Thèses : « Nanocomposites - Physical Properties »

1

Kalakonda, Parvathalu. « Thermal Physical Properties Of Nanocomposites Of Complex Fluids ». Digital WPI, 2013. https://digitalcommons.wpi.edu/etd-dissertations/301.

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"Composites of nanoparticles with complex fluids represent a unique physical system where thermal physical properties of the components partially or fully mix and new behavior can emerge. Traditional composites are relatively well understood as the superposition, weighted by volume or mass, of the components properties and the interfacial interactions play the role of holding the composite together. As the filler component, nanoparticle, decreases in size, the surface area begins to dominate, leading to unique behavior of the nanocomposites. The richness of the nanocomposites that can be designed by coupling various nanoparticles and complex fluid materials opens a wide field of active research. This dissertation presents a series of experimental studies on various nanocomposites using modulated differential scanning calorimetry, spectroscopic ellipsometry, dielectric spectroscopy, polarizing microscopy, and conductivity measurements of nanoparticles such as multi-wall carbon nanotubes and quantum dots on the phase transitions of several liquid crystals and polymers. The liquid crystals (LCs) and liquid crystalline polymer (LCP) of interest are: negative dielectric anisotropy alkoxyphenylbenzoate (9OO4), octylcyanobiphenyl (8CB), decylcyanobiphenyl (10CB), and isotactic polypropylene (iPP) which can form smectic liquid crystal (LC) phase. Studies have been carried out as a function of concentration and temperature spanning through various ordered phases. The results indicate a mixture of ordering and disordering effects of the nanoparticles on the phases of the complex fluids. In 9OO4/CNT system, dipole moment of liquid crystal and graphene like surface can allow a random dispersion of CNT to promote both orientational and positional order. For nCB/CNT, nCB/Quantum dot (QD) systems, nanoparticles induce net disordering effect in LC media. The effect of QDs on LC depends on the anchoring conditions and the QDs size. The results clearly demonstrate that the nematic phase imposes self-assembly on QDs to form one dimensional arrays. This leads to net disordering effect. The thermal/electrical conductivity changes in thin films of iPP/CNT sheared/un-sheared samples and it also varies with temperature for the purpose of inducing anisotropy of those properties in parallel and perpendicular to average orientation. The percolation threshold is clearly pronounced in both conductivities due to pressing and shearing treatment of the films. This will further our abilities to nano-engineer material for many important applications."

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Wincheski, Russell A. « Characterization of the physical properties of iron polyimide nanocomposites ». W&M ScholarWorks, 1999. https://scholarworks.wm.edu/etd/1539623960.

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The discovery of tunneling magneto-resistance has led to a great deal of interest in the study of ferromagnet-insulator-ferromagnet (FIF) systems due to potential sensor and magnetic storage applications. An analysis of the band structure of the 3d ferromagnets shows that the conduction electrons become spin polarized by the molecular field. The transmission coefficient of these electrons across a tunneling gap therefore depends upon the relative alignment of the molecular field between the two ferromagnets.;In this work the manufacture of such tunneling gaps through compression molding of powdered ferromagnetic iron with a high performance polyimide has been studied for the first time. The percent change in the resistance with applied magnetic field depends critically on the volume percentage of ferromagnetic material in the composite. A peak in the tunneling magnetoresistance (TMR) occurs at a volume concentration just beneath the percolation threshold of the ferromagnetic material. The change in resistance relative to the resistance at zero field, DeltaR/R0, obtains a room temperature peak value of -4.5% at 20% iron volume concentration.;Granular conducting systems near the percolation threshold are also subject to variable range hopping (VRH) conduction. The charging energy of small metallic grains results in an energy barrier for the acceptance of an additional electron. Electronic conduction requires thermal activation over this barrier along with tunneling through the insulating regime. The result of these two combined processes is a temperature dependent tunneling distance and a conductivity of the form ln sigma ∝ T-x, with 1/4 ≤ x ≤ 1/2.;The theoretical development and experimental measurements of TMR and VRH in iron polyimide nanocomposites are thoroughly developed and analyzed in this work. Ferromagnet particle size and band structure effects on TMR are also explored in an effort to optimize the material for sensor applications.

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Nasiri, Aida. « Development of Safe-by-Design Nano-composites for Food Packaging Application ». Thesis, Montpellier, 2017. http://www.theses.fr/2017MONTT076.

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Ce projet contribue à développer la prochaine génération de nano-emballages en utilisant une approche plus sûre et éco-conçue avec des avantages directs à la fois pour l'environnement et la sécurité des consommateurs. Les emballages alimentaires constituent l’un des principaux secteurs d’applications des nanotechnologies avec des enjeux environnementaux prometteurs de substitution des pétro-plastiques par des bio-plastiques et de réduction des pertes et gaspillages alimentaires grâce à des emballages plus performants, de type actifs et intelligents. Dans le cas de matériaux nano-composites (matrice polymérique contenant des nano-particules) destinés au contact alimentaire, le risque majeur en terme de santé humaine est lié à leur impact sur la migration de composés indésirables de l’emballage vers l’aliment (stabilisants UV, antioxydants, plastifiants, etc) qui peuvent avoir des effets néfastes en fonction des doses et durées d’exposition. Ces interactions contenant/contenu sont soumises à une réglementation européenne dont l’objectif est la protection de la santé du consommateur en fixant des limites de migration spécifique pour tous les composés supposés entrer dans la composition des matériaux plastiques dédiés au contact alimentaire. Dans le cas des nanomatériaux, la présence de nanoparticules est susceptible de modifier les interactions entre le polymère et les additifs et par voie de conséquence leurs propriétés de transfert. Ainsi, la formalisation des phénomènes de migration de l’emballage vers l’aliment établie sur des matériaux plastiques ne contenant pas de nanoparticules ne peut pas être directement transposée au nano-matériaux. De plus la présence de ces nanoparticules peut profondément modifier l’éco-toxicité environnementale du système matrice- nanoparticule -additif.La présente étude vise à comprendre et contrôler l’impact des structures nanocomposites (matrice polymérique contenant des nano-particules) sur les propriétés de transport (diffusivité et solubilité) des nanoparticules et des additifs chimiques en condition d’usage. À cet égard, il est nécessaire de combler le déficit de connaissances dans a caractérisation de la structure 3D, des propriétés physico-chimique et des interactions aux interfaces entre nanoparticules et matrice dans les nanomatériaux. Devant la complexité du système étudié, la modélisation est indispensable pour représenter (simplifier sans pour autant perdre trop de connaissances) la structure 3D des nanomatériaux et simuler, reproduire puis prédire, l’évolution de leurs propriétés de transfert en fonction des paramètres structurels et en condition d’usage. La modélisation des transferts est également indispensable pour, dans une approche d’ingénierie inverse, éco-concevoir et dimensionner à façon des nano-emballages sûrs pour l’Homme et l’Environnement. Dans cette optique une démarche de modélisation multi-échelle des relations structure/propriétés de transfert de masse a été mise en place sur des matériaux nanocomposites ciblés choisis pour leur pertinence dans le domaine de l’emballage alimentaire
The market of nanotechnologies is dominated by the food packaging area which amounts more than 20% of the total nanotechnologies market in 2015. However, the wide-scale use of nanomaterials raises important questions about environmental and safety issues that could hinder their development. In the case of plastics intended to be in contact with food, the risk of contamination concerns not only the nanoparticles but also all the chemical additives added during the material processing. The presence of nanoparticles is susceptible to modify the interactions between polymer and the additives with a possible change in their transport properties and therefore the food contamination.The present work aims at identifying the relationship between the structural characteristic and the transport properties (diffusivity and solubility) of nanoparticles and chemical additives incorporated in nanocomposites. In this regard, it is necessary to fill the gap of knowledge in 3D nanostructure characterization and a multi-scale modeling of mass transfer properties of nanocomposites in real usage conditions.In this way, polyethylene and nanoclay were selected based on the best compromise between real potential applications and the scientific knowledge previously published and eventually the nanocomposites were synthesized with LLDPE, Cloisite20 and a compatibilizer by melt intercalation method.The nanocomposite structure was characterized using TEM, X-ray nanotomography, TGA and XRD then submitted to migration tests undertaken in contact with different food simulants which represent various types of food (aqueous, acid, alcoholic) following the recommendation of the European regulation on the food contact material. To evaluate the positive or adverse effects of the nanomaterials on the contamination of the food by chemical additives which are usually incorporated with the plastic packaging, the virgin polymer and nanocomposite material were spiked with a mixture of the additives exhibiting various volatility, polarity and molecular weight. Then, the transport properties (i.e inertia) of nanocomposite structure was distinctively investigated on kinetic (apparent diffusion coefficient) and thermodynamic (partition coefficient) considerations.The results indicated that nanoclay addition in plastic materials favorably reduced the migration of additives by modifying both their diffusivity in the polymer and their partition between the polymer and the food simulant. However, while the partition coefficient of additives increases in nanocomposite in comparison to pure LLDPE for the samples in contact with all types of food simulants, the reduction of diffusion coefficient is significantly dependent on the nature of the food simulant in contact. Hence, it can be concluded that the major role in the migration of additives is not played by the imposed tortuosity path, but by the factors such as the affinity between the base polymer and simulants as well as the effects of simulants on swelling and crystallinity of the samples. Moreover, the effect of additive-related parameters and the structural parameters were assessed and put in perspective with their impact on the transport properties of nanostructures. Integrating the results of characterization and transfer properties led to an improved understanding of the influence of structure of nanocomposites on their mass transfer properties and therefore on the suitability of using them as food contact materials

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Nel, Alicia. « Investigation of the effect of chitin nanowhiskers distribution on structural and physical properties of high impact polypropylene/chitin nanocomposites ». Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/95981.

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Thesis (MSc)--Stellenbosch University, 2014.
ENGLISH ABSTRACT: Polymer composites have been gaining more importance in our daily lives because of the favorable properties that can be provided by these types of material. A polymer composite consists of improved properties when compared to the individual polymers that it is compiled of. The reason that composites are better than the individual polymers is mainly because composites are a combination of all the bene cial properties from the individual materials that was used to make the polymer composite. High impact polypropylene (HiPP) is a complex copolymer that was developed to overcome the restrictions of polypropylene (PP). Although PP have excellent properties at lower temperatures, it loses these advantages at elevated temperatures. High impact polypropylene has a much better impact strength and is processable at high temperatures. High impact polypropylene has been studied in depth for its applications and its superior properties such as an improved impact strength. The tensile properties, after the incorporation of a nano ller, have however not been investigated to our knowledge. Nano llers have reinforcing abilities due to the nano-scale diameters. Particles that have sizes on a nanometer range are mostly devoid of defects. Nano llers that are biopolymers have additional advantages such that can consist of antimicrobial abilities, renewability, biocompatibility and biodegradability. Composites reinforced with chitin nanowhiskers (chnw) have shown to have valuable applications in the latest medical, industrial and environmental developments. Di erent loadings of chnw were incorporated into a HiPP matrix in order to investigate the e ects that this nano ller will have on the tensile properties of HiPP. There were two challenges that required attention during the incorporation of chnw into HiPP. The rst major challenge was the poor interaction that exist between chnw and HiPP due to the hydrophobic nature of the HiPP matrix and the hydrophilic nature of chnw. The second problem was the agglomeration that can occur because of the hydrogen bonding between the chnw that is caused by the structure of the chnw chains. In order to gain the best dispersion of chnw within the HiPP matrix it was necessary to use compatibilizers and di erent methods of incorporation. The two types of compatibilizers that were chosen to improve the compatibility between the HiPP matrix and chnw were polypropylenegraft- maleic anhydride (PPgMA) and poly(ethylene-co-vinyl alcohol)(EVOH). Injection molding is typically used to process HiPP and was chosen as one of the methods for incorporating chnw into the HiPP matrix. A second method of incorporation was used speci cally for the nancomposites containing EVOH known as electrospinning combined with meltpressing. Tensile testing, DSC, TGA and FTIR were used to investigate the changes in the mechanical and thermal properties of the nanocomposites. SEM and TEM were employed to investigate the morphology of the electrospun ber mats and to characterize the chnw. FTIR as well as TGA were used to characterize the chitin nanowhiskers and to identify the individual components within the nanocomposites after incorporation took place. The incorporation of chnw along with the compatibilizer did show improvement in some mechanical properties of the polymer matrix. However, the in uence that each type of compatiblizer had on this e ect varied depending on the content of the chnw and compatibilizer with regards to the polymer matrix.

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Guha, Ingrid F. « Effects of silica nanoparticle surface treatment and average diameter on the physical and mechanical properties of poly(dimethylsiloxane)-silica nanocomposites ». Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/118564.

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Thesis: S.B., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2010.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 35-37).
The purpose of this thesis was to quantify the effects of silica nanoparticle surface treatments and average silica nanoparticle diameter on various macroscopic properties of poly(dimethylsiloxane)-silica nanocomposites, specifically stiffness, wettability, and permeability to organic solvents. Poly(dimethylsiloxane)-silica nancomposites were prepared with constant amounts (4.8 wt%, 1.8 vol%) of fumed silica nanoparticles with varying surface treatments (hexamethyldisilazane and octamethylcyclotetrasiloxane) and varying particle diameter (7 and 12 nm). The Young's elastic modulus, mass increase due to dodecane absorption after 10 minutes, and advancing and receding water contact angles were measured for each nanocomposite. PDMS-silica nanocomposites containing untreated silica nanoparticles were found to have a higher Young's elastic modulus than nanocomposites containing hexamethyldisilazane-treated silica nanoparticles with the same diameter. However, nanocomposites containing identically sized silica nanoparticles with and without the octamethylcyclotetrasiloxane surface treatment had the same stiffness. The average nanocomposite stiffness increased slightly as the untreated silica nanoparticle diameter decreased from 12 nm to 7 nm. Varying the surface treatment or particle diameter of the filler did not significantly affect the level of dodecane absorption or the wettability of the nanocomposite. All nanocomposites showed approximately 20-23 wt% increase from dodecane absorption after 10 minutes of dodecane immersion. All nanocomposites exhibited average advancing contact angles around 115-120° and average receding contact angles around 85-90°. Nanocomposites were imaged using optical coherence tomography to examine particle dispersion. Potential differences in particle dispersion are discussed.
by Ingrid F. Guha.
S.B.

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Ali, Samer Shaur. « Fundamental interactions and physical properties of starch, poly vinyl alcohol and montmorillonite clay based nanocomposites prepared using solution mixing and melt extrusion ». Thesis, Kansas State University, 2010. http://hdl.handle.net/2097/6983.

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Master of Science
Department of Grain Science and Industry
Sajid Alavi
Plastics from petroleum sources are the main raw materials used for producing food packaging films. But these plastic films cause a great environmental concern due to their non-degradable nature and non-renewable source. Biodegradable polymers like starch can be used as a base material which can replace petroleum based plastics packaging. In this study, starch (0-80%) and polyvinyl alcohol (PVOH) (20-100%) were used as base polymers to produce nanocomposites. Glycerol (30%) and sodium montmorillonite (0-20%) were used as a plasticizer and nano-filler, respectively. Nanocomposites were produced through two methods: solution and melt extrusion method. Extrusion method resulted in greater exfoliation of nanocomposites than solution method because it provided more shear stress to disrupt the layered silicate structure. In extrusion method, a lab scale extruder was used to produce these nanocomposites and films were made by casting. Process parameters, including screw speed (200-400 RPM) and barrel temperature (145-165[superscript]oC), were varied systematically. X-ray diffraction (XRD) and transmission electron microscopy (TEM) were conducted to characterize the nanostructure of these nanocomposites. Thermal characterization of these films was carried out through differential scanning calorimetric (DSC) studies. Results from XRD and TEM explained the phenomenon of intercalation and exfoliation in these nanocomposites. Structural and thermal data indicated important role for Na[superscript]+MMT along with process parameters in controlling exfoliation and glass transition temperature of the nanocomposites. These results also helped in understanding the fundamental interactions among all the components. The tensile strength and elongation at break of films ranged from 4.72 to 23.01MPa and 63.40 to 330.15% respectively, while water vapor permeability ranged from 1.68 to 0.79g.mm/kPa.h.m[superscript]2. These results provide a great understanding for further improvements in order to bring these films close to commercial plastic films which have superior tensile strength (10-80MPa), elongation at break (200-800%) and water vapor permeability (0.002- 0.05g.mm/kPa.h.m[superscript]2). The cost for polyethylene is approximately $0.70/lb while the raw material cost for this starch based films is approximately $0.85/lb.

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Aldroe, Hanaya. « Analyse des propriétés physiques et mécaniques des nanocomposites polyamide 12 / cloisite® 30B en lien avec leurs nanostructures ». Thesis, Tours, 2014. http://www.theses.fr/2014TOUR4034/document.

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Les nanocomposites suscitent un intérêt croissant depuis leur développement dans les années 90 par Toyota. Par conséquent, l'amélioration des propriétés de ce type de matériaux est un enjeu fort tant d'un point de vue fondamental qu'industriel. Cette amélioration peut passer par un choix pertinent des charges renforçantes ajoutées à la matrice notamment en ce qui concerne le type, la géométrie, la proportion et le traitement de ces charges. L’optimisation des paramètres d’élaboration du mélange y joue aussi un rôle important. L’objectif de ce travail est de contribuer à l’identification et à la compréhension des mécanismes à l'origine du renforcement des matrices thermoplastiques par des nanocharges. Cet aspect est abordé à travers l’étude des propriétés thermiques et mécaniques des nanocomposites formés d’une matrice Polyamide 12 (PA12) chargées par des nanoparticules d’argile organiquement modifiée. Plus précisément, nous avons analysé les effets de la fraction massique des charges et du vieillissement naturel sur les propriétés structurales, thermiques et mécaniques de ces nanocomposites. L’influence des conditions de mélangeage sur ces propriétés ont aussi été examinées. Nous avons particulièrement mis l’accent sur l’identification des liens qui existent entre les propriétés macroscopiques et la structure des nanocomposites. Nous avons aussi fait une étude comparative des propriétés viscoélastiques de ces matériaux à l'état fondu et à l'état solide, ce qui représente une des originalités forte de ce travail
Nanocomposites are interestingly growing since their development in the 1990s by Toyota Company. Therefore, improving the properties of such materials is a major issue from fundamental and industrial point of view. This improvement can pass through a relevant choice of reinforcing loads added to the matrix particularly regarding the type, geometry, the proportion, and the treatment of these fillers. The processing parameters of the mixture play also a key role. The objective of this work is to contribute to the identification and understanding of the mechanisms at the origin of the reinforcing thermoplastic matrices by nanofillers. This aspect presented through the study of the thermal and mechanical properties of nanocomposites formed by a polyamide 12 matrix (PA12) filled with organically modified clay nanoparticles. More specifically, we analysed the effects of the filler mass fraction and environmental aging on structural, thermal and mechanical properties of these nanocomposites. The mixing conditions on these properties were also examined. A particular attention has been paid to the study of relationships between the macroscopic properties and the structure of nanocomposites. Viscoelastic properties of these materials in both melt and solid states were compared, which represents one of the originalities of this work

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Bhole, Y. S. « Investigations on gas permeation and related physical properties of structurally architectured aromatic polymers (polyphenylene oxides and polyarylates), polyarlate-clay nanocomposites and poly ( ionic liquid) ». Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2007. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/2578.

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Ali, Zulfiqar [Verfasser], Hans-Joachim [Akademischer Betreuer] Radusch et G. [Akademischer Betreuer] Heinrich. « Analysis of morphology development during the mixing process of rubber-clay nanocomposites and correlation to their mechanical-physical properties / Zulfiqar Ali. Betreuer : Hans-Joachim Radusch ; G. Heinrich ». Halle, Saale : Universitäts- und Landesbibliothek Sachsen-Anhalt, 2009. http://d-nb.info/102489617X/34.

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Njuguna, Michael Kamau. « Characterisation of multi wall carbon nanotube–polymer composites for strain sensing applications ». Thesis, Queensland University of Technology, 2012. https://eprints.qut.edu.au/54671/1/Michael_Kamau_Njuguna_Thesis.pdf.

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Carbon nanotubes (CNTs) have excellent electrical, mechanical and electromechanical properties. When CNTs are incorporated into polymers, electrically conductive composites with high electrical conductivity at very low CNT content (often below 1% wt CNT) result. Due to the change in electrical properties under mechanical load, carbon nanotube/polymer composites have attracted significant research interest especially due to their potential for application in in-situ monitoring of stress distribution and active control of strain sensing in composite structures or as strain sensors. To sucessfully develop novel devices for such applications, some of the major challenges that need to be overcome include; in-depth understanding of structure-electrical conductivity relationships, response of the composites under changing environmental conditions and piezoresistivity of different types of carbon nanotube/polymer sensing devices. In this thesis, direct current (DC) and alternating current (AC) conductivity of CNT-epoxy composites was investigated. Details of microstructure obtained by scanning electron microscopy were used to link observed electrical properties with structure using equivalent circuit modeling. The role of polymer coatings on macro and micro level electrical conductivity was investigated using atomic force microscopy. Thermal analysis and Raman spectroscopy were used to evaluate the heat flow and deformation of carbon nanotubes embedded in the epoxy, respectively, and related to temperature induced resistivity changes. A comparative assessment of piezoresistivity was conducted using randomly mixed carbon nanotube/epoxy composites, and new concept epoxy- and polyurethane-coated carbon nanotube films. The results indicate that equivalent circuit modelling is a reliable technique for estimating values of the resistance and capacitive components in linear, low aspect ratio-epoxy composites. Using this approach, the dominant role of tunneling resistance in determining the electrical conductivity was confirmed, a result further verified using conductive-atomic force microscopy analysis. Randomly mixed CNT-epoxy composites were found to be highly sensitive to mechanical strain and temperature variation compared to polymer-coated CNT films. In the vicinity of the glass transition temperature, the CNT-epoxy composites exhibited pronounced resistivity peaks. Thermal and Raman spectroscopy analyses indicated that this phenomenon can be attributed to physical aging of the epoxy matrix phase and structural rearrangement of the conductive network induced by matrix expansion. The resistivity of polymercoated CNT composites was mainly dominated by the intrinsic resistivity of CNTs and the CNT junctions, and their linear, weakly temperature sensitive response can be described by a modified Luttinger liquid model. Piezoresistivity of the polymer coated sensors was dominated by break up of the conducting carbon nanotube network and the consequent degradation of nanotube-nanotube contacts while that of the randomly mixed CNT-epoxy composites was determined by tunnelling resistance between neighbouring CNTs. This thesis has demonstrated that it is possible to use microstructure information to develop equivalent circuit models that are capable of representing the electrical conductivity of CNT/epoxy composites accurately. New designs of carbon nanotube based sensing devices, utilising carbon nanotube films as the key functional element, can be used to overcome the high temperature sensitivity of randomly mixed CNT/polymer composites without compromising on desired high strain sensitivity. This concept can be extended to develop large area intelligent CNT based coatings and targeted weak-point specific strain sensors for use in structural health monitoring.

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Tokarski, Tomasz. « Nanomechanical properties of nanocomposite polymer layer ». Thesis, KTH, Skolan för kemi, bioteknologi och hälsa (CBH), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-261161.

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Interphase phenomenon gains more and more interest throughout the research community. An interphase is formed between a filler particle and a polymeric matrix, and it may constitute almost the entire volume of a nanocomposite. If the interphase have favorable mechanical properties it will thus result in a nanocomposite with such properties. Therefore, understanding the principles of its formation and properties are crucial in order to design advanced nanocomposites. This thesis focuses on PDMS-carboxylic acid modified latex nanoparticles (PDMS-CML) surface composites investigated by means of Atomic Force Microscopy (AFM). A new sample preparation method was designed and utilized together with the Gel Trapping Technique (GTT). Quantitative Imaging Mode and Contact Mode were utilized in the AFM studies. Topography and nanomechanical properties were investigated and compared for pure PDMS and PDMS containing the nanoparticles. Further, Contact Mode was used to investigate nanoscale wear of the samples in order to elucidate the interactions strength between the nanoparticles and the matrix.
Egenskaper hos interfaser är ett område som röner allt större intresse hos forskarna inom materialområdet. En interfas bildas mellan en fillerpartikel och en polymermatris, och den kan utgöra den största volymen i en nanokomposit. Ifall interfasen har fördelaktiga mekaniska egenskaper så resulterar det alltså i att nanokompositen också får det. Det är därför viktigt att först principerna för hur interfasen bildas och får sina egenskaper om man vill framställa avancerade nanokompositer. I det här avhandlingsarbetet lades fokus på PDMS och karboxylsyrefunktionaliserade latex nanopartiklar som bildade en nanokomposit yta, vilken studerades med atomkraftsmikroskopi (AFM). En ny framställningsmetod togs fram och utnyttjades tillsammans med den så kallade ”Gel Trapping” tekniken (GTT). Quantitative Imaging och kontakt mode utnyttjades vid AFM studierna. Topografin och de nanomekaniska egenskaperna studerades för ren PDMS och PDMS blandat med nanopartiklarna. Nötning på nanometernivå studerades också, och dä med AFM i kontakt mode.

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Stojak, Kristen L. « Synthesis and Properties of Polymer Nanocomposites with Tunable Electromagnetic Response ». Thesis, University of South Florida, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=1535889.

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Multifunctional polymer nanocomposites (PNCs) are attractive for the design of tunable RF and microwave components such as flexible electronics, attenuators, and antennas due to cost-effectiveness and durability of polymeric matrices. In this work, three separate PNCs were synthesized. Magnetite (Fe₃O₄) and cobalt ferrite (CFO) nanoparticles, synthesized by thermal decomposition, were used as PNC fillers. Polymers used in this work were a commercial polymer provided by the Rogers Corporation (RP) and polyvinylidene fluoride (PVDF). PNCs in this thesis consist of Fe₃O₄ in RP, CFO in RP, and Fe₃O₄ in PVDF. Characterization techniques for determining morphology of the nanoparticles, and their resulting PNCs, include x-ray diffraction, transmission electron microscopy and magnetometry.

All magnetometry measurements were taken using a Quantum Design Physical Property Measurement System with a superconducting magnet. Temperature and external magnetic field magnetization measurements revealed that all samples exhibit superparamagnetic behavior at room temperature. Blocking temperature, coercivity and reduced remnant magnetization do not vary with concentration. Tunable saturation magnetization, based on nanoparticle loading, was observed across all PNCs, regardless of polymer or nanoparticle choice, indicating that this is an inherent property in all similar PNC materials.

Tunability studies of the magneto-dielectric PNCs were carried out by adding the PNC to cavity and microstrip linear resonator devices, and passing frequencies of 1–6 GHz through them in the presence of transverse external magnetic fields of up to 4.5 kOe, provided by an electromagnet. Microwave characteristics were extracted from scattering parameters of the PNCs. In all cases, losses were reduced, quality factor was increased, and tunability of the resonance frequency was demonstrated. Strong magnetic field dependence was observed across all samples measured in this study.

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Stojak, Kristen Lee. « Synthesis and Properties of Polymer Nanocomposites with Tunable Electromagnetic Response ». Scholar Commons, 2013. http://scholarcommons.usf.edu/etd/4587.

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Multifunctional polymer nanocomposites (PNCs) are attractive for the design of tunable RF and microwave components such as flexible electronics, attenuators, and antennas due to cost-effectiveness and durability of polymeric matrices. In this work, three separate PNCs were synthesized. Magnetite (Fe3O4) and cobalt ferrite (CFO) nanoparticles, synthesized by thermal decomposition, were used as PNC fillers. Polymers used in this work were a commercial polymer provided by the Rogers Corporation (RP) and polyvinylidene fluoride (PVDF). PNCs in this thesis consist of Fe3O4 in RP, CFO in RP, and Fe3O4 in PVDF. Characterization techniques for determining morphology of the nanoparticles, and their resulting PNCs, include x-ray diffraction, transmission electron microscopy and magnetometry. All magnetometry measurements were taken using a Quantum Design Physical Property Measurement System with a superconducting magnet. Temperature and external magnetic field magnetization measurements revealed that all samples exhibit superparamagnetic behavior at room temperature. Blocking temperature, coercivity and reduced remnant magnetization do not vary with concentration. Tunable saturation magnetization, based on nanoparticle loading, was observed across all PNCs, regardless of polymer or nanoparticle choice, indicating that this is an inherent property in all similar PNC materials. Tunability studies of the magneto-dielectric PNCs were carried out by adding the PNC to cavity and microstrip linear resonator devices, and passing frequencies of 1-6 GHz through them in the presence of transverse external magnetic fields of up to 4.5 kOe, provided by an electromagnet. Microwave characteristics were extracted from scattering parameters of the PNCs. In all cases, losses were reduced, quality factor was increased, and tunability of the resonance frequency was demonstrated. Strong magnetic field dependence was observed across all samples measured in this study.

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Furuya, Tsutomu. « Structure Formation and Physical Properties of Aqueous Polymer Solutions and Hydrogels with Additives ». Kyoto University, 2019. http://hdl.handle.net/2433/236625.

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Mortazavi, Bohayra, et Bohayra Mortazavi. « Multiscale modeling of thermal and mechanical properties of nanostructured materials and polymer nanocomposites ». Phd thesis, Université de Strasbourg, 2013. http://tel.archives-ouvertes.fr/tel-00961249.

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Nanostructured materials are gaining an ongoing demand because of their exceptional chemical and physical properties. Due to complexities and costs of experimental studies at nanoscale, computer simulations are getting more attractive asexperimental alternatives. In this PhD work, we tried to use combination of atomistic simulations and continuum modeling for the evaluation of thermal conductivity and elastic stiffness of nanostructured materials. We used molecular dynamics simulations to probe and investigate the thermal and mechanical response of materials at nanoscale. The finite element and micromechanics methods that are on the basis of continuum mechanics theories were used to evaluate the bulk properties of materials. The predicted properties are then compared with existing experimental results.

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Yang, Hui-Chen, et 楊慧真. « Preparation and Physical Properties ofPoly(Lactic Acid) Nanocomposites ». Thesis, 2010. http://ndltd.ncl.edu.tw/handle/76105489054709957916.

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碩士
國立中興大學
化學工程學系所
98
This research used Poly-Lactic Acid as the main material due to its fine biocompatibility. However, the differences in heat resistance due to the slower crystallization rate of Poly-Lactic Acid is the major limit on application now. The purpose of this research was to probe into the different fillers by adding in Poly-Lactic Acid, adding SiO2, Glycidyloxypropyl trimethoxysilane ( GPS ) modified SiO2 , montmorillonite Cloisite15A , modified clay, and the multi-walled carbon nanotube. The addition of all these materials were all capable to enhance the mechanical properties and thermal properties of Poly-Lactic Acid. For the Poly-Lactic Acid/SiO2 nanocomposites and Poly-Lactic Acid /carbon nanotube nanocomposites, compatibilizers were used to enhance the dispersion, and especially adding carbon nanotube will enable Poly-Lactic Acid to provide with electrical conductivity to biodegradable materials. Nanocomposites had been prepared from Poly-Lactic Acid separately with SiO2 , GPS modified SiO2, montmorillonite Cloisite15A, modified clay, and carbon nanotubes by melt blending. The mechanical properties analyzed by DMA show that the storage modulus (E’) of Poly-Lactic Acid at the room temperature of 30 ℃was 1.48×109 Pa. However, the storage modulus (E’) of the composites had all increased after adding the content of either GPS modified SiO2 or not, montmorillonite Cloisite15A,modified clay, and carbon nanotubes. Comparisons with the same contents of 5.0 phr inorganic materials showed that carbon nanotubes with the storage modulus (E’) increases to 1.92×109 Pa ,while Cloisite15A to 1.88×109 Pa, GPS modified SiO2 to 1.87×109 Pa , SiO2 to1.84×109 Pa, and modified clay to 1.66×109 Pa. The results of the thermal properties through the analysis of DSC, the results showed that SiO2 , GPS modified SiO2, montmorillonite Cloisite15A,modified clay, carbon nanotubes could increase efficiently the crystalline degree of Poly-Lactic Acid . The crystalline degree of Poly-Lactic Acid is 2.2 %, by comparing with the same 5.0 phr contents of inorganic materials, carbon nanotubes increased to 30.5 % were best, while Cloisite15A to 25.9 %, modified clay to 25.5 %, GPS modified SiO2 to 10.9 %,and SiO2 to 9.22 %. All nucleating agents had been found to enhance the heat resistance of Poly-Lactic Acid . The addition of Poly-Lactic Acid crystals could result in the correspondence of the crystalline degrees of composites with the respective storage modulus (E’). This was because the crystal storage modulus (E’) was a lot greater than the respective amorphous storage modulus (E’). Moreover, the addition of either with or without GPS modified SiO2 after the annealing process to induce Poly-Lactic Acid to make integrated crystals when compared with the same 5.0 phr content of inorganic compounds, GPS modified SiO2 increased to 46.6 % and SiO2 to 38.3 % . The resistance of Poly-Lactic Acid is 2.3×1014 Ω‧cm, electrical conductivity of the composites increase after adding carbon nanotube, adding 5.0 phr contents of carbon nanotubes, while the resistance of the composites decrease to 8.03×105 Ω‧cm.

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17

Wang, Jyun-Xian, et 王俊賢. « Preparation and Physical Properties of Polyacrylate / Montmorillonite Nanocomposites ». Thesis, 2016. http://ndltd.ncl.edu.tw/handle/62030945717051722569.

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碩士
國立中興大學
化學工程學系所
104
In this study, montmorillonite (MMT) was modified to prepare polyacrylate/modified montmorillonite nanocomposite films by UV polymerization. UV curable monomers employed include the hydrophobic 1, 6-Hexanedio diacrylate (HDDA) and hydrophilic ethoxylated trimethylopropane triacrylate (ETTA). First, quaternary ammonium salt (QA) was added to montmorillonite, and grafted onto MMT by adsorption. Tetraethyl orthosilicate (TEOS) was then added to form silica on the MMT surface. Subsequently, the grafting of 3-(trimethoxy silyl)-1-propanol methacrylate (MPS) on MMT/SiO2 (QACS) was done to bring the C=C function groups. Finally, methyl methacrylate and butyl acrylate were polymerized on the outer surface of MMT/SiO2 nanohybrids by surface polymerization. The Si-O-Si vibrational stretching at 1082 cm-1 from MMT/SiO2 nanohybrids is revealed by FTIR. Via XRD analysis, we found that MMT/SiO2 nanohybrids exhibitting no diffraction peaks from 1.5 to 8 degree byWAXD, suggesting the distance of interlayers of MMT above 5.88 nm (1.5o). Silica nanoparticles on the clay surface were observed by SEM. The C=C stretching vibration at 1637 cm-1 belonging to MPS grafted on silica was confirmed by FT-IR. By TGA analysis, the amount of grafted MPS in MMT/SiO2 nanohybrids was evaluated as 0.18 g MPS/g QACS ( = 0.36 g MPS/g MMT). For surface polymerization, methyl methacrylate and butyl acrylate monomers at weight ratio of 3:1 were added to obtain poly(methyl methacrylate-co-butyl acrylate) on MMT/SiO2 nanohybrids. The characteristic peaks of methyl methacrylate and butyl acrylate were observed from FTIR. Furthermore, polyacrylate/modified MMT nanocomposites were prepared by UV polymerization. By FTIR monitoring, the C=C double bond disappeared after polymerization, indicating polymerization successful. Comparing the transmittance data at 550 nm by UV-vis, while the content of MMT was increased from 0 wt% to 1.5 wt%, the transmission decreased from 93.1% to 89.9% in polymerized HDDA/modified MMT nanocomposites. On the other hand, the transmission decreased from 96.3% to 94.2% in polymerized ETTA/modified MMT nanocomposites. The transmission of polymerized ETTA and HDDA films were slightly affected by the presence of modified MMT due to its good dispersion. For pencil hardness test, while the content of MMT was increased from 0 wt% to 1.5 wt%, it was found that the hardness increased from 6H to 9H in HDDA/modified MMT nanocomposites, and the hardness increased from 3H to 6H in the ETTA/modified MMT nanocomposites. For static water contact angle analysis, while the content of MMT increased from 0 wt% to 1.5 wt%, the contact angles of HDDA/modified MMT nanocomposites was measured from 63.9o to 81.8o. For ETTA/modified MMT nanocomposites, the angles increased from 55.6o to 71.2o. For the fracture surface texture by SEM, the distance between polyacrylate/MMT nanocomposites texture was reduced compared with pure polyacrylate films, indicating that MMT improved the toughness of polyacrylate/MMT nanocomposites.

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18

曾子凡. « Preparation and physical properties of polyethylene/silica nanocomposites ». Thesis, 2003. http://ndltd.ncl.edu.tw/handle/30379823474808412081.

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碩士
國立中興大學
化學工程學系
91
Abstract In this study, amino silane coupling agent was used for the surface modification of silica. The modified silica, linear low density polyethylene ( LLDPE ) and polyethylene grafted malic anhydride ( PE-g-MA ) were melt blended in Brabender mixer to prepare PE/Silica nanocomposites. Fourier Transform Infrared Spectrophotometer confirmed the Si-O-Si bonding of silica and polysiloxane at 771 and 1017 cm-1. The N-H absorption of six-member ring consists of amine group of polysiloxane and hydroxyl group of silica with 1588 cm-1. The formation of amide via the reaction of amine group on silica and anhydride group of compatibilizer showed weak absorption at 1645 and 1560 cm-1. Thermal Gravimetric Analysis gives an increases of 18℃ in 5 wt % loss temperature for silica reinforced LLDPE. Analysis of isothermal crystallizatin kinectics data showed that the Avrami index of pure LLDPE is 3.1. With the addition of silica into LLDPE matrix , Tmo is found to be decreased, the n value decrease to 2.1, t1/2 increases from 6.87 minutes ( E ) to 14.50 minutes ( E-S-3 ), measured at 120℃. While for 6 phr silica addition, t1/2 was decreasing to 4.71 minutes. With the addition of compatibilizer and 6 phr of SA3 into LLDPE matrix. Also, Tmo is found to be decreased. For t1/2, it was found that the value is 2.77 minutes for EM-12 and 0.90 minutes for EM-12-SA3-6. Polarized Optical Microscopy reveals that silica in matrix shows the heterogeneous nucleation effect. Scanning Electron Microscope and Field Emission Scanning Electron Microscope are used to observe the cracking surface of nanocomposites at low temperatures. It is found that silica are only well dispersed in PE matrix with good interfacial adhesion, when the compatibilizer and silane modified silica are added simultaneous. Dynamic mechanical data shows the addition of silica enhance the E’ at -100℃. For E” at γ relaxation, the peak temperature increases with the addition of silica and the damping amplitude also increases.

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19

林玉涵. « Preparation and physical properties of polymer electrolytes nanocomposites ». Thesis, 2003. http://ndltd.ncl.edu.tw/handle/68472134561536156510.

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20

Lin, Ting-Wei, et 林鼎維. « Preparation and Physical Properties of Epoxy/Modified Montmorillonite Nanocomposites ». Thesis, 2014. http://ndltd.ncl.edu.tw/handle/15503334305467649136.

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碩士
國立中興大學
化學工程學系所
102
In this study, we first prepared the modified montmorillonite (MMT) having epoxy functional groups and added it into the epoxy to form nanocomposites. The curing agent is polyetheramine, D230, that used for the preparation of nanocomposites by ring-opening reaction of the epoxy functional groups in epoxy resin. The modified MMT was done by treating MMT with a modified silane (MS), and Then tetraethylorthosilicate (TEOS) was added to form nanosilica particles on the MMT surface. Then, the reaction of 3-(Trimethoxy silyl)-1-propanol methacrylate (MPS) on MMT/SiO2 nanohybrids (C1S1) was done to bring the C=C function groups. Finally, glycidyl methacrylate (GMA) and styrene were polymerized on the outer surface of MMT/SiO2 nanohybrids by admicellar polymerization. Because the glycidyl methacrylate itself contains epoxy functional group, it can enhance the dispersion of modified MMT dispersed in epoxy resin. Hence, it can be expected to improve the compatibility and uniform dispersion in the epoxy resin. For admicellar polymerization, glycidyl methacrylate and styrene monomers at weight ratio of 1:3 were added to obtain poly (glycidyl methacrylate-co-styrene) grafted on a MMT/SiO2 nanohybrids grafted with MPS. The characteristic spectrometric peaks of glycidylmethacrylate and styrene were studied by FTIR. The Si-O vibrational stretching form MMT/SiO2 nanohybrids is revealed. We found that MMT/SiO2 nanohybrids exhibit no diffraction peaks between 1.5 to 8 degree by XRD, suggesting the distance of interlayer of modified clay above 5.88 nm (1.5°). Subsequently, the epoxy/modified MMT nanocomposites were prepared and further analyzed. By XRD analysis, it was shown that the exfoliation of modified MMT at 1~3 wt % loading was achieved. By inspecting the SEM fracture photographs, we found that the surface structure was covered with stripes for epoxy/modified MMT nanocomposites. When the modified MMT in the nanocomposites reaches 3.0 wt %, the number of stripes were increased significantly. In the DMA analysis, the glass transition temperature was measured. While adding 1、2、3 wt % modified MMT in nanocomposites, the glass transition temperatures were dropped to 80.5 ℃、71.5 ℃、71.1 ℃ compared with 86.3 ℃ for pure epoxy resin after curing. The decrease of glass transition temperature is explained by the confinement of polymer chains embedded in the MMT gallery and limits their segmental motions and results in insufficient crosslinking density. Also, the storage modulus was studied. The E’ value increased form 2.73 E8 Pa for pure epoxy, to 2.88、2.95、2.99 E8 Pa for 1、2、3 wt % modified MMT in nanocomposites at 30 ℃. The increased percentage of E’ value was found to be 5.47、8.13、9.72 % for 1、2、3 wt % loading of modified MMT.This means the modified MMT can effectively enhance the storge modulus. From the oxygen transmission rate analysis, the oxygen permeability decreased form 2.97 cc/m2-day matrix substrate to 2.42、0.76、0.42 cc/m2-day of 3、6、9 wt % of modified MMT of nanocomposites. We can see the oxygen barrier properties of polymers can be significantly increased by inclusion of clay platelets due to the increase of diffusion path for gas molecules. Finally, the oxygen transmission rate further was analyzed and found the MMT platelets form this thesis shows the aspect ratio of 350 for MMT dispersed in epoxy nanocomposite.

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21

Lee, Wei-Lun, et 李維倫. « A Study on Physical Properties of Polyurethane/Clay Nanocomposites ». Thesis, 2000. http://ndltd.ncl.edu.tw/handle/20046425542374093235.

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碩士
國立雲林科技大學
工業化學與災害防治研究所
88
The purpose in the study is to research the relationships of structure-property on the polyurethane(PU) /clay nanocomposites. The PU matrix are prepared by two stage method. PU soft segment of the matrix include polyester and polyether type, and chain extenders include m-phenylenediamine-4-sulfonic acid(PDSA) and 1,4-butanediol(1,4BD). The natural clay is modified by intercalating reagent form organocaly for better disperse in the PU matrix. The effects of different amounts of organoclay and the kinds of soft segment and chain extender of PU on the degree of dispersion of organoclay in the PU matrix are researched in the study. The structure and physical properties were measured by X-ray diffraction(XRD), atomic force microscpoe(AFM), dynamic mechanical analyzer(DMA), differential scanning calorimeter(DSC) thermogravimeter analysis(TGA) and Tensile testrespectively. The results show that degree of dispersion of organoclay on the nanocomposites depend on the content of organoclay, soft segment type and chain extender type within PU matrix in the study.The soft segments based on polyether, and functional chain extender PDSA would be resulted into the better degree of dispersion on the nanocomposites. The better dispersion degree of nanocomposite system, the more excellent mechanical and thermal properties. From the d-space data, measured by the X-ray diffraction, the structure on the PU/Clay composites are proved as nanometer dispersion. Furthermore, the thermal properties reveal the thermal degradation temperature(5wt% loss) of PU/Clay nanocomposite increase with increasing the contents of organoclay.

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22

Yang, Chun-Cheng, et 楊承鈞. « Preparation and Physical Properties ofEpoxy Resin/Montmorillonite/Silica Nanocomposites ». Thesis, 2009. http://ndltd.ncl.edu.tw/handle/56215989950132990052.

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碩士
國立中興大學
化學工程學系所
97
In this study, the amino propyl trimethoxy silane was used for the surface modification of silica, and the modified silica was adsorbed to surface of clay/silica (SiO2 : Clay = 4:1 and 2:1) and the clay/silica was adsorbed by the surfactant. Also, we used Dimethyldistearylammonium chloride (DMDSAC) and Dodecyltriphenylphosphonium (DTPPB) surfactant to modify clay/silica. Then we prepared the Epoxy/clay/silica nanocomposites and Epoxy/clay/silica/DOPO composites. In FTIR analysis, we found the Si-O-Si bond of silica and amino silane at 1114 cm-1, the N-H absorption peak emerges at 1564 cm-1, and the C-H absorption peak occurs at 2858 cm-1, 2926 cm-1. In DSC analysis, we found the glass transition temperature of nanocomposites were 152.0 oC and 150.1 oC, when the content of clay were 1.2 wt % and 2.0 wt% respectively. When the temperature of post cure in preparing nanocomposites reaches 200 oC, the glass transition temperature of nanocomposites were 178.0 oC and 170.3 oC. Therefore, increasing the temperature of post cure can lead the nanocomposite crosslinked completely and the segmental mobility of epoxy polymer decreased with the consequence of higher glass transition temperatures. In TEM studies, we found the d-spacing of clay galleries were enlarged by silica particles and clay platelets were highly exfoliated. When the clay in nanocomposites reached 0.2 wt %, the d-spacing of clay was 30 ~ 40 nm. When the clay in the nanocomposites reached to 1.2 wt % and 2.0 wt %, the d-spacing of clay was 30 nm and 20 nm, respectively.We found, in the nanocomposites containing 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO) flame retardant, when the content of clay were 1.2 wt % and 1.9 wt %, the clay aggregate more and the d-spacing was 20 and 15 nm respectively. In the analysis of TGA, the thermal decomposition temperature of nanocomposites at TG = 95 % decreases with the increase of DOPO, the char yield is high at 800 oC. In LOI studies, the LOI of pure epoxy is 26.3. When adding the DOPO in the pure epoxy, the LOI is 28.3. The LOI of nanocomposites increases to 32.0 when the clay in the nanocomposites reaches 1.9 wt %. When the amount of clay in the nanocomposites increases to 1.8 wt %, the LOI of nanocomposites is 30.5. It is suggest that nanocomposites with clay can improve the flame retardancy and the in corporation of silica enhances the contact surface area between clay and epoxy resin and hence becomes more flame retardant. In the analysis of DMA, when the post cure temperature of nanocomposites is 150 oC, the E’ value increase from 19.2 % to 61.3 % at 35 oC. When the post cure temperature of nanocomposites is 200 oC, the E’ value increased from 1.8 % to 43.5 % at 35 oC. With the addition of the DOPO in the nanocomposites under the clay content from 0.4 wt % to 1.9 wt %, the E’ value increases from 8.8 % to 27.4 % at 35 oC.

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23

Li, Hsin-Chiung, et 李新炯. « Physical and Thermal Properties of Nylon 6/ABS nanocomposites ». Thesis, 2006. http://ndltd.ncl.edu.tw/handle/51842222814339713252.

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碩士
長庚大學
化工與材料工程研究所
94
The physical and thermal properties of nanoclay-filled Nylon 6 (Nano-Nylon 6) and Nylon 6 blended with poly(acrylonitrile-butadiene-styrene) terpolymer (ABS) prepared through a twin screw extruder were investigated using maleic a anhydride-grafted polyolefin elastomer (POE-g-MA) or a maleic anhydride-grafted polybutadiene (PB-g-MA) as a compatibilizer to enhance the interfacial interaction. TEM, XRD and SEM/EDS results confirmed that for the Nano-Nylon 6/ABS system the clay was dispersed homogeneously and exfoliated in Nano-Nylon 6, and no discernible effect of both compatibilizers on the dispersibility of clay in the matrix has been observed. Through SEM and POM observation, the ABS particle sizes tended to decrease with the addition of compatibilizers, especially in PB-g-MA included blends. DSC results indicated that the additions of compatibilizers significantly affected the crystalline structure of Nano-Nylon 6. The crystallization kinetics of the sample was analyzed with the Avrami equation. TGA results showed that the thermal stability of Nano-Nylon 6/ABS matrix was slightly enhanced with adding PB-g-MA and POE-g-MA. Similar behavior were observed for Nylon 6/ABS blends system.

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24

江俊杰. « Preparation and Physical Properties of Nylon 6/Silica Nanocomposites ». Thesis, 2002. http://ndltd.ncl.edu.tw/handle/97368265022057687249.

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碩士
國立中興大學
化學工程學系
90
Abstract This study was aimed to prepare surface-modified silica followed by melt blending with Nylon 6 via two processes. One is the adsorption of cationic surfactant on silica, the other is the grafting of styrene/glycidyl methacrylate copolymer on silica surface though surface polymerization. These surface-modified silicas has been applied to preparation of Nylon 6/silica nanocomposites through melt mixing. Differential Scanning Calorimeter (DSC) result showed that the addition of silica into nylon 6 matrix increase the crystallization rate as well as the crystallization peak temperature (Tp) and also induce the crystallization into the less stable γcrystalline form. Non-isothermal crystallization kinectics data shows that the Avrami index, n, of vigin nylon 6 is 2.74 whereas for the nylon 6/silica nanocomposites with 5 wt% content is 4.89. Transmission electron microscopy (TEM) reveals the surface-modified silica in nylon 6 matrix is well dispersed. Finally, nylon 6 /silica nanocomposites were analyzed by DMA for measuring storage modulus (E’) , loss modulus (E”) and loss factor (tanδ). The storage modulus of nanocomposites containing 5 wt% silica modfied by adsorption of single cationic surfactant layer was 2.1 times that of virgin nylon 6. For silica modified by poly(styrene-glycidyl methacrylate) copolymer with silica content of 5 wt% , the storage modulus was 2.7 times that of pure nylon 6.

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25

彭俊彥. « Preparation and physical properties of thermoplastic polyurethane /montmorillonite nanocomposites ». Thesis, 2002. http://ndltd.ncl.edu.tw/handle/25905148124684152339.

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碩士
國立中興大學
化學工程學系
90
Abstract The MMT-master batch is introduced in proportion to the matrix of Thermolplastic Polyurethane (TPU) by kneading process to prepare nanocomposites in this study. This master batch is prepared by the negatively charged MMT adsorbed with cationic polyelectrolytes in the water phase and then “coagulated” with negatively charged Polyurethane Dispersion (PUD). Characterized by FTIR and DSC, the compatibility of PUD with TPU matrix of the master batch is confirmed. The result of XRD demonstrated that the d-spacing of MMT is greater than 4.4 nm. The storage modulus, as compared with TPU, increased 59% at -100℃ and 43% at 25℃, respectively at 5 wt% MMT loading. The tensile strength and elongation at break of TPU nanocomposite at 3 wt % MMT also increases 38% and 23%, respectively. In this research, we demonstrated the preparation of TPU/MMT nanocomposite by kneading process with improved mechanical and thermal properties as compared with those of TPU.

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HsinHsien, Lin, et 林信賢. « Preparation and Physical Properties of Polymethyl methacrylate/Montmorillonite Nanocomposites ». Thesis, 2001. http://ndltd.ncl.edu.tw/handle/27972185062862190313.

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碩士
國立中興大學
化學工程學系
89
Polymethyl methacrylate (PMMA) latex and methyl methacrylate-butyl actylate copolymer latex were prepared by microemulsion polymerization using anionic surfactant dodecyl sulfate sodium salt. By adsorbing cationic polyelectrolytes, the montmorillonite （MMT） surfaces carry positive charges. Therefore, the polymer/MMT complexes can be obtained through adsorbing negative charge latex particles on the surfaces of MMT. The MMT d-spacings and contents in compls were analyzed by X-ray diffraction (XRD) and Thermogravimetric Analyzer (TGA), respectively. Subsequently, PMMA/MMT nanocomposites were prepared through bulk polymerization of methyl methacrylate (MMA) along with polymer/MMT complexes, or bleexending polymer/MMT complexes and PMMA by a Brabender mixer. The d-spacings, glass transition temperatures, and modulus (E’, E’’ and tanδ）of these nanocomposites were analyzed by XRD, Differential Scanning Calorimeter (DSC) and Dynamic Mechanical Analyzer (DMA), respectively. As compared to the pristine PMMA, the storage modulus (E’) of the nanocomposites with 3 wt% of MMT prepared through bulk polymerization and Brabender-mixing exhibit increase percentages of 40 % and 32 %, respectively. It is important to note that adding an appropriate amount of polybutyl acrylate (PBA) to the MMT-containing nanocomposites prepared via bulk polymerization will further improve the storage modulus. In this research, the PMMA/MMT nanocomposites with excellent mechanical properties were successfully developed by bulk polymerization and Brabender-mixing.

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27

yun, Lee ya, et 李雅雲. « Synthesis and physical properties of nanocomposites waterborne epoxy resin ». Thesis, 2011. http://ndltd.ncl.edu.tw/handle/84133440772126409419.

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碩士
國立高雄師範大學
化學系
99
The first part is the study on waterborn epoxy resin which was obtained by non-ionic surfactants agent emulsifier through temperature phase inversion (EPW-100). The EPW-100 further mixed with the hardening agent 6868B and variable amount of montmorillonite、bentonite、kaolinite and water-soluble nanocalcium carbonate to form a nanocomposite materials. The properties including tensile strength, pen-hardress and water resistance were investigated by XRD, SEM, DSC, TGA, etc. The second part is the study on the synthesis of antibacterial Ag nanoparticles by using hydrothermal reduction method. The results exhibit the Ag NP containing waterborne epoxy is a good antibacterial agent for E. coli and P.a(pseudomonas aeraginosa).

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Ku, Cheng-Cheng, et 古承正. « Preparation and Physical Properties of Silica Grafted PMMA Nanocomposites ». Thesis, 2019. http://ndltd.ncl.edu.tw/handle/c96254.

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碩士
國立中興大學
化學工程學系所
107
The aim of this research is to produce PMMA/silica nanocomposites which have better dispersity and heat resistance. Silica nanoparticles were prepared by sol-gel method and modfied by coulping agent, 3-(trimethoxy silyl)-1-propanol methacrylate (MPS). We further divided three different admicellar systems to graft polymethyl methacrylate (PMMA) on the silica particles surface by adding different kinds of surfactants. Finally, we analyzed heat resistance and conversion of product and observe particles size and morphology. In this research, we added different weight ratio of MPS to modify silica particles and observed by SEM. We used three systems. System (A) used the cation of VBDDAC adsorb on silica particles at first, form admiclle by mixing different kinds of surfactant and PMMA was grafted on surface. System (B) mixed cationic surfactant hexadecyl-trimethyl ammonium bromide (CTAB) to form bilayer micelle on the surface of silica and grafted PMMA. System (C) used anionic surfactant Sodium dodecyl sulfate (SDS) to form admicelle and grafted PMMA on the surface of silica. The size of silica particles, produced by sol-gel method, was about 7~10 nm. The mean diameter of modified silica particle by adding 0.15 and 0.3 g MPS/g silica was about 15 nm. In system (A), we found that the admicelle formed by VBDDAC and CTAB could lead to 4 g PMMA grafted on 1g silica surface. Td5 was higher than 270℃. Particles sizes was between 30~80 nm. In system (B), increasing the additional ratio of MPS from 0.15 to 0.3 g/g silica can improve the conversion of monomer from 65% to 86%. Adding NaHCO3(aq) as buffer made system more stable during polymerization and could reach the conversion to 100%. Adding some cationic monomer DMAPMA could decrease the particles size to 20 nm and got better dispersity. In system (C), all samples had good stability and better heat resistance (Td5 is 270±5℃). The increased ratio of MPS from 0.15 to 0.6 g/g silica could improve grafted efficiency and increased conversion from 67 to 86%. Increasing temperature to 80 ℃ and removing ethanol before polymerization could achieve the conversion of 90%.

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Liu, Wei-Yi, et 劉威毅. « Preparation and Physical Properties of UV Curable Acrylate / Montmorillonite Nanocomposites ». Thesis, 2011. http://ndltd.ncl.edu.tw/handle/09522661463346084104.

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碩士
國立中興大學
化學工程學系所
99
In this study, the montmorillonite was modified to prepare acrylate/ montmorillonite nanocomposites film by UV polymerization. UV curable monomers employed are the hydrophilic ethoxylated trimethyl opropane triacrylate (ETTA) and hydrophobic 1, 6-Hexanediol diacrylate (HDDA). The montmorillonite treated with a modified silane (MS), and then tetraethyl orthosilicate (TEOS) was added to form nanosilica particles on the clay surface. Then, the reaction of 3- (Trimethoxy silyl)-1-propanol methacrylate (MPS) on Clay/SiO2 nanohybrids (CSN) was done to bring the C=C function groups. Finally, styrene and methyl methacrylate were polymerized on Clay/SiO2 nanohybrids by admicellar polymerization. MS was added to clay for the preparation of Clay/SiO2 nanohybridss. The Si-O vibrational stretching from Clay/SiO2 nanohybrids is revealed by FTIR. SiO2 nanoparticles on the clay surface were observed by SEM. Via XRD analysis, we found that Clay/SiO2 nanohybrids exhibitting no diffraction peaks from 1.5 to 8 degree by WAXD, suggesting the distance of interlayers of modified clay above 5.88 nm (1.5°). Via TGA, we evaluated the amount of grafted MPS in Clay/SiO2 nanohybrids as 0.84 m-mole MPS/g CSN. The Si/Al atomic ratio of Clay/SiO2 increases with MPS as measured by Energy Dispersive X-ray Spectroscopy (EDS). The C=C vibrational stretching belonging to MPS grafted on silica was confirmed by FTIR. For admicellar polymerization, styrene and methyl methacrylate monomers at different weight ratio were added to obtain poly(styrene-co-methyl methacrylate) on Clay/SiO2 nanohybrids. The characteristic peaks of styrene and methyl methacrylate were observed from FTIR. Subsequently, acrylate/modified montmorillonite nanocomposites were prepared by UV polymerization. Via the fracture surface texture by SEM, the dispersion of PMMA modified montmorillonite in polyacrylates is better than that of commercial montmorillonites. Commercial montmorillonites employed are the Cloisite 15A and Cloisite 30B. In the polymerized ETTA/modified montmorillonite nanocomposites studied by DSC, we found the Tg of polymerized ETTA increased from -44.6 ℃ to -41.6 ℃. On the other hand, the Tg of polymerized HDDA increased 3.7 ℃ from 92.4 ℃ to 96.1 ℃ in the polymerized HDDA/modified montmorillonite nanocomposites. This is explained by the confinement of polymer chains embedded in the montmorillonite gallery and limits their segmental motions. In the polymerized ETTA/modified montmorillonite nanocomposites studied by pencil hardness test, the hardness increased from 3 H to 6 H. On the other hand, the hardness increased from 6 H to 8 H in the polymerized HDDA/modified montmorillonite nanocomposites. Comparing the transmission data at 500 nm by UV-vis,The transmission decreased from 98.94 % to 96.81 % in polymerized ETTA/modified montmorillonite nanocomposites. On the other hand, the transmission decreased from 98.74 % to 97.14 % in the polymerized HDDA/modified montmorillonite nanocomposites. The transmission of polymerized ETTA and HDDA films were slightly affected by the presence of the clay/SiO2 nanohybrids due to its good dispersion.

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30

楊席珍. « Preparation and physical properties of styrene-acrylonitrile copolymer/montmorillonite nanocomposites ». Thesis, 2000. http://ndltd.ncl.edu.tw/handle/39903005343328549719.

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碩士
國立中興大學
材料工程學研究所
88
Abstract The preparation of styrene-acrylonitrile/MMT nanocomposite was done by quasi-emulsion polymerization in adsorbed cetyl trimethylammonium bromide (CTAB) micelles on MMT. Various amounts of MMT in SAN/MMT nanocomposites were prepared. The samples were analyzed by XRD、TGA to obtain d-spacing of MMT and content of MMT. The low MMT content SAN/MMT composites were prepared by two methods. One is by bulk polymerization, the other is done in a Brabender mixer. The measured E'、E'' and tanδ of SAN/MMT nanocomposites by Dynamic Mechanical Analyzer was compared with those of pure SAN copolymer. Then, XRD、TEM were employed to observe the d-spacing and dispersion of MMT in SAN matrix. Results show that the SAN/MMT nanocomposites can be prepared by bulk polymerization and melt blending. And, MMT was dispersed in SAN uniformly. The storage modulus (E') of SAN/MMT composites are higher than those of pure SAN with an increase percentage of 72 % and 61 % , respectively. Both the d-spacing of the SAN/MMT nanocomposites were measured to be greater than 200~300 nm from TEM. In this study, we have successfully prepared SAN/MMT nanocomposites with mechanical properties improved by MMT reinforcement.

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31

Wu, Shiou-Miin, et 吳秀敏. « Preparation of PTFE/SiO2 Nanocomposites Boards and their Physical Properties ». Thesis, 2005. http://ndltd.ncl.edu.tw/handle/96826981804005556029.

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碩士
逢甲大學
紡織工程所
93
Abstract With the rapidly development of electric communication, the FR-4 Boards will not be suitable in all kinds of properties, especially in dielectric property. In order to improve the transmission of the High-Frequency Board at high frequency state, we must bring the dielectric properties under control. The composite materials of inorganic powder-PTFE board are the ideal material of high frequency board. In the study, we utilize inorganic powders (SiO2 and Hollow glass particle) to reinforce the PTFE board, then the PTFE/inorganic is completed, we discuss the effect of different of PTFE matrix and the particle sizes and the particle contents on the dielectric, thermal and mechanism properties of PTFE/inorganic Board. The experimental results, show that PTFE resin-emulsion and PTFE film has the similar properties of dielectric, mechanical and thermal behavior. Dielectric and thermal properties are increased, with the increasing of powder content；however the mechanical properties are decreased.

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32

Lee, Po-Yuan, et 李柏源. « Preparation and Physical Properties of Polymethyl methacrylate/Zinc oxide Nanocomposites ». Thesis, 2009. http://ndltd.ncl.edu.tw/handle/16879641000800397642.

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碩士
國立中興大學
化學工程學系所
97
The main purpose of this study is to fabricate zinc oxide/polymethyl methacrylate (ZnO/PMMA) nanocomposites with well-dispersed ZnO nanoparticles. Firstly, we used solution polymerization to prepare the copolymers (ABM copolymers) made of acrylic acid (AA), butyl acrylate (BA) and methyl methacrylate (MMA), and the ratios of these three monomers (AA:BA:MMA) had been respectively varied to 1:2:7, 2:2:6 and 3:2:5. In the following experiments, we used solution blending method to mix ZnO nanoparticles and ABM copolymers together. In XRD and FTIR analysis, we found that the carboxylic acid groups of ABM copolymer could dissolve ZnO crystalline and adsorbed onto the surface of ZnO nanoparticles. In the sedimentation test, we observed that ABM copolymers enhanced the stability of dispersion of ZnO nanoparticles in the hydrophobic organic solvent. Furthermore, we used solution blending, bulk polymerization and melt blending method to fabricate ZnO/PMMA nanocomposites. The ABM copolymers had been used as compatibilizers for ZnO nanoparticles dispersed in PMMA matrix. The carboxylic acid groups of ABM copolymers can adsorb onto the surface of ZnO nanoparticles, and the hydrophobic moiety of ABM copolymers can compatibilize with PMMA matrix. Via XRD analysis, we found that the ZnO nanoparticles had been dissolved more severely as the portion of acrylic acid in the ABM copolymer raised. In DSC and DMA analysis, we found that ZnO nanoparticles and ABM copolymers had no apparent influence on the glass transition temperature and the mechanical strength of PMMA matrix. Data from TGA analysis indicate that ZnO nanoparticles evidently enhance the thermal stability of PMMA matrix. However, the addition of the easily decomposed ABM copolymers in PMMA reduces the thermal stability of PMMA matrix. Via UV-vis analysis, we observed that adding ZnO nanoparticles into PMMA matrix dramatically decreased the transparency of ZnO/PMMA nanocomposites films. Whereas adding ABM copolymers into ZnO/PMMA nanocomposites as the compatibilizers can increase the transparency of ZnO/PMMA nanocomposites films. Hence, it’s obvious that the ABM copolymers improved the dispersibility of ZnO nanoparticles in PMMA matrix. After inspected by SEM and TEM analysis, we found that if ZnO/PMMA nanocomposites containing ABM copolymers as compatibilizers, ZnO nanoparticles would loosely and widely disperse in PMMA matrix. In addition, the capability of ABM copolymer to improve the dispersibility of ZnO nanoparticles increases with the portion of acrylic acid in the ABM copolymer. Therefore, we suggest that the amount of carboxylic acid groups in ABM copolymer is one of the important factors to aid the dispersion of ZnO nanoparticles in PMMA matrix.

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33

Wang, Xiao-Min, et 王孝民. « Preparation and Physical Properties of Poly(vinyl alcohol)/Silica Nanocomposites ». Thesis, 2008. http://ndltd.ncl.edu.tw/handle/42247361403755505051.

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碩士
國立中興大學
化學工程學系所
96
In this research, we used tetraethyl orthosilicate (TEOS) as the precursor to fabricate SiO2, and then we used the SiO2 modifier - GT to perform surface modification on SiO2; further, we used solution blend method and in-situ method to produce the nanocomposites of PVA/ SiO2 from PVA. In this study, we varied the content of SiO2 to discuss how SiO2 affected the PVA’s physical properties and after modifying SiO2 by GT to investigate the effects to PVA/SiO2 composites. 　　We analyzed the fabricated PVA/SiO2 composites via DSC and found PVA’s glass transition temperatures enhanced with the increase of the content of SiO2. When the content of SiO2 in the composites reached to 20 wt%, the glass transition temperature of the composites produced by in-situ in acid condition enhanced by 6.9 ℃, and it enhanced by 6.1 ℃ and 2.9 ℃ respectively in the in-situ in basic condition and solution blend method. Due to SiO2 and PVA in the composites brought the hydrogen bonding interaction to restrain PVA’s chains movemwnt. When the content of SiO2 increased, polymer chains needed more energy to mobilize, so we observed the increase of glass transition temperature. After modifying SiO2 in the composites by GT, due to the OH groups on SiO2 increased, we could enhance the hydrogen bonding interaction between SiO2 and PVA to lead the glass transition temperature of the composites to increase again. In the composites made by in-situ in acid condition, the modified SiO2 had 1.0 ℃ more than the unmodified SiO2 in the comparison of the glass transition temperature, and it increased by 5.3 ℃ and 2.7 ℃ respectively in the in-situ in basic condition and solution blend method. 　　In the TGA analysis, we found that PVA’s thermal decomposition temperature at 5 % weight loss increased with the content of SiO2. When the SiO2 in the composites reached to 20wt%, the thermal decomposition temperature at 5 % weight loss of the composites made by in-situ in acid condition increased by 17.8 ℃and it increased by 11.7 ℃ and 8.9 ℃ respectively for the in-situ basic condition and solution blend method. Because the SiO2 in the composites inhibited thermal motion in the chains of PVA, the thermal decomposition temperature at 5 % weight loss enhanced. After modifying the SiO2 in the composites by GT, the thermal decomposition temperature at 5 % weight loss of the composites also increased again. In the composites made by in-situ acid condition, the thermal decomposition temperature of the one had modified SiO2 increased by 5.8 ℃ at 5 % weight loss, in the comparison with the one had unmodified SiO2. In the in-situ in basic condition, the enhancement of the thermal decomposition temperature was 14.7℃. In solution blend method, the thermal decomposition temperature at 5 wt% loss decreased by 4.0℃. 　　In the analysis of XRD, the degree of crystallinity of PVA decreased with the increase of the content of SiO2. When the SiO2 in the composites reached 30wt%, the degree of crystallinity of the composites made by in-situ in acid condition decreased by 18.8% and decreased by 16.9% and 12.7% respectively in in the in-situ in basic condition and solution blend method. Due to the hydrogen bonds between SiO2 and PVA, it reduced the interaction among the chains of PVA; hence, PVA’s degree of crystallinity decreased. After modifying the SiO2 in the composites by GT, because the OH groups on the SiO2 surface increased and interacted with the hydroxyl groups of PVA, the degree of crystallinity for PVA decreased again. In the composites made by in the in-situ in basic condition and solution blend method, the degree of crystallinity of the modified SiO2 and that without SiO2 decreased by 3.7% and 1.4% respectively. However, it increased 3.3% for the in-situ at acid condition. 　　In the FESEM analysis of fracture surfaces, when the content of SiO2 in the composites reached 30 wt%, the particles of SiO2 still well-dispersed in the matrix of PVA and there was no aggregation. SiO2 had good dispersion in PVA, so there was no apparent effect on the dispersion of SiO2 after we modified the SiO2 in the composites by GT. The diameter of the particles of SiO2 was around 5 nm to 20 nm.

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34

Yeh, Chia-Hsing, et 葉佳炘. « Preparation and Physical Properties of Poly(ethylene terephthalate)/Silica Nanocomposites ». Thesis, 2006. http://ndltd.ncl.edu.tw/handle/83010820933673601165.

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碩士
國立中興大學
化學工程學系所
94
In this research, two methods were used to modify silica. For the first method, we modified silica with GPS to form epoxy group grafted silica surface.For the second method, we used AEE to react with epoxy group to obtain hydroxyl group. Modified silica were dispersed in EG and mixed with TPA, BHET and catalyst. The mixture was made to be polymerized to synthesize the PET/SiO2 nanocomposites through standard polymerization steps of PET. Intrinsic viscosities of these nanocomposites were 0.51 ~ 0.70 and average molecular weight of these nanocomposites were 13520 ~ 25130. According to the data of TGA at 5 % loss, as the content of modified silica increased in PET matrix, the decomposition temperature increased 11.1℃. DSC showed that the crystallization temperature increased from 171.2 ℃ to 198.5 ℃ and the melting point of PET/SiO2 nanocomposites increase from 241.2 ℃ to 248.3 ℃ at cooling rate of 10 ℃/min. For nonisothermal crystallization kinetics, data were carried out with half-time of crystallization of PET/SiO2 nanocomposites decreasing from 3.50 min to 3.48 ~ 1.69 min at cooling rate of 10 ℃/min and the those Avrami indices of PET/SiO2 nanocomposites are between 2.48 and 2.96. For isothermal crystallization, kinetics data were carried out with half-time of crystallization of PET/SiO2 decreasing from 2.07 min to 0.16 ~ 1.28 min at isothermal crystallization temperature of 200 ℃ and those Avrami indices of PET/SiO2 are between 1.61 and 2.05. Polarized Optical Microscopy revealed that the addition of modified silica in PET increased the rate of crystallization grown at isothermal crystallization temperature of 225 ℃ and the crystal of PET crystallized at 225 ℃ were unusual spherulites. DMA data shows that the storage moduli of PET/1 ~ 3 wt% GPS modified silica nanocomposites were 1.17 E9 Pa ~ 1.33 E9 Pa, and the storage moduli of PET/1 ~ 3 wt% AEE-GPS modified silica nanocomposites were 1.49 E9 Pa ~ 1.53 E9 Pa at 30 ℃. FE-SEM morphology studies observed a good dispersion of the modified silica dispersion in PET matrix, having average particles diameter of 40 to 50 nanometers. EDS morphology studies observed the modified silica dispersion in PET matrix, having average particles diameter of 36 nanometers. TEM morphology observed the modified silica dispersed in PET matrix, having average particles diameter of 50 to 100 nanometers.

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35

Chen, Kinch, et 陳金旗. « Preparation and Physical Properties of Poly(butylene terephthalate)/Silica Nanocomposites ». Thesis, 2004. http://ndltd.ncl.edu.tw/handle/30405014926826364615.

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碩士
國立中興大學
化學工程學系
92
Abstract The silica-master batch is introduced in proportion to the matrix of Poly(butylenes terephthalate) (PBT) by melt blending to prepare nanocomposites in this study. This master batch is prepared by the modified silica adsorbed with cationic surfactant in the water phase. The XRD data demonstrated that the d-spacing of silica in nanocomposites is greater than 4.4 nm. Thermal Gravimetric Analysis gives an increases of 2.1℃ at 50 wt % loss temperature for silica reinforced PBT. Crystallization kinetics data at non-isothermal crystallization were carried out with t1/2 of PBT/silica nanocomposites decreased from 4.04 min to 0.82〜1.13 min at cooling rate of 5 ℃/min and the Avrami index of PBT/silica is between 3.3 and 4.03. Isothermal crystallization studies were also carried out with t1/2 of PBT/silica nanocomposites decreased from 1.2 min to 0.26〜0.33 min at crystallization temperature of 200 ℃. The Avrami index of PBT/silica nanocomposites is 2.58〜3.55 while that for PBT is 2.24. Polarized Optical Microscopy reveals that the addition of silica in PBT increases the density of nucleating site and decreases the size of crystallites grown in PBT matrix. Dynamic mechanical data shows the addition of silica enhances the storage moduli from 8.33×108 Pa to 9.11×108〜1.16×109 Pa measured at 30 ℃. The glass transition temperature increasing from 55.05 ℃ to 56.74〜58.95℃.

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36

蔡秉凱. « Preparation and physical properties of silicone oil/silica fluid nanocomposites ». Thesis, 2004. http://ndltd.ncl.edu.tw/handle/77900561065482888693.

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碩士
國立中興大學
化學工程學系
92
Abstract In this study, the silicone oil is synthesized via octamethylcyclotetrasiloxane（D4） and hexamethyldisiloxane by acid cayalyst and under the dosage of sulfuric acid is 1.0 wt ％, the viscosity reaches equilibrium after 5 ~ 6 hours. By 29Si-Nuclear Magnetic Resonane analysis, the absorbances of silicone in (-Me2SiO-) and (Me3SiO-) are close to -22 ppm and 6 ppm. Epoxy silane coupling agent（GPS） and D4 are used for the surface modification of silica. By Fourier Transform Infrared Spectrophotometer analysis, the absorbances of epoxy ring breathing is 1254 cm-1, asymmetric ring stretching absorbance is 822 cm-1, Si-CH3 rocking and CH deformation absorbances of silicone oil are 1028 cm-1 and 1263 cm-1. By Solid State 29Si-Nuclear Magnetic Resonane analysis, the bond absorbances of GPS and silica are at -68.52, -57.03 and -48.71 ppm. The contact angle of water on unmodified silica is 19.0 o and the contact angles of water on modified silica is 91.0 o. With the addition of 1 phr and 3 phr silica into silicone oil , the viscosity increase from 976.8 cp to 1184 cp and 1431 cp. The 50 wt ％ loss temperatures increase from 544 ℃ to 572 ℃ and 578 ℃ for commercial silicone oil, mO970. The particles size of modified silica are between 25 ~ 50 nm in silicone oil by FE-SEM analysis. By DMA analysis, the tanδof the silicone/silica composite fluid which containing 1 phr and 3 phr silica raise from 5.35 for pure oil to 8.02 and 13.36.（based on marketed silicone oil, mO970）

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37

Cheng-hsing, Fan, et 范正欣. « Preparation and Physical Properties of Liquid Crystalline Polymer / Montmorillonite Nanocomposites ». Thesis, 2004. http://ndltd.ncl.edu.tw/handle/12536767744972055005.

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碩士
國立中興大學
化學工程學系
92
In this research, surface agents including DTPPB and 2P4QCA were used as templates for the modification of montmorillonite (MMT) surface.According to the technology of thermotropic liquid crystalline polymer Type Ⅱ Vectra’s polymerization, each acetoxy-monomer ( (A-HBA , A-HNA , A-BP) mole (%) = ( 73 , 27 , X ) X=0、0.5、1.0) of LCP and 1 phr modified MMT were made into LCP / MMT nanocomposites through melt polycondensation reactions.With 2P4QCA content increase, it increase the dispersion of modified clay in the nanocomposites, because it can react with acetoxy-monomers and produce acetic acid.Therefore thermal, mechanical and other properties of the nanocomposites will increase.The addition of small amounts of acetoxy-BP will control molecule weights of LCP.It can react with acetoxy-monomers and produce acetic acid to form copolyesters, because more acetoxy groups will increase reactive rate and lower the time of polymerization. Therefore it will terminate the reaction and control molecule weights of LCP and thermal and mechanical properties of the nanocomposites will lower.TEM reveals that most clay layers of organoclay were intercalated.DSC result showed that Tm and Tc of LCP / MMT nanocomposites increase 0.5~1.5 oC, POM reveals that LCP / MMT nanocomposites still have liquid crystallinity and were nematic schlieren textures.The isotropic temperature lower 2~3 oC owing to the addition of modified MMT, DMA reveals that storage modulus (E'') of nanocomposites increase 10~30 (%).

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38

Feng, Chiang Ming, et 江明峰. « Preparation and Physical Properties of Poly(lactic acid)/Montmorillonite Nanocomposites ». Thesis, 2004. http://ndltd.ncl.edu.tw/handle/04220101016110932087.

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碩士
國立中興大學
材料工程學研究所
92
A milestone in the history of mankind can be described by the use of different materials, which are the Stone Age, the Bronze Age and etc. According to the development of technology, synthetic polymers are gradually popular and convenient in life. Many problems, such as the consumption of natural resources and pollution of the environment come out at the same time. Therefore, the request for “Eco-Green” materials is increasing, which means that more interests in developing with biodegradability and biocompatibility material. Poly(lactic acid) (PLA), Poly(ε-caprolactone) (PCL), and chitosan all have good biocompatibility and biodegradability. However, PLA with low flexibility contains good physical and mechanical properties, but PCL and chitosan with low mechanical properties process good flexibility. According to their own nature, the application is limited. By adding different ratio of PCL and chitosan into PLA can improve its original behavior. Also, it expects that the addition of montmorillonite into the system can reinforce the mechanical property of material and form a complementary degradable polymeric nanocomposite to promote its application. Therefore, a blend by mixing PCL/Chitosan with various amount of PLA has been prepared. Montmorillonite is succeeded treated by CTAB and lactic acid emulsion to increase larger thickness and chemical affinity of montmorillonite and PLA. The addition of chitosan can further increase the distance between layer and layer to 40 Å which is useful for the subsequent dispersion of PLA. In this research, the effects by adding PCL and chitosan into PLA nanocomposite on the physical properties and morphologies can be analysed by DSC, TGA, FTIR, DMA, SEM and TEM.

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39

Haung, Wei Lung, et 黃偉倫. « The Physical Properties Of PMMA/Clay Nanocomposites By Melt Blending ». Thesis, 2010. http://ndltd.ncl.edu.tw/handle/87546298475346011255.

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40

Lin, Chien-Chih, et 林建志. « Investigation on physical and chemical properties of organic-inorganic nanocomposites ». Thesis, 2010. http://ndltd.ncl.edu.tw/handle/13607253279618194384.

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博士
臺灣大學
高分子科學與工程學研究所
98
This thesis is devoted to polymer-silica nanocomposites to study its physical and chemical properties. It contains three parts, the first part is to monitor the nanophase transition of the nanocomposites, the second part is to discuss effects of nanoparticle sizes and type of polymer chemical structures on the properties of nanocomposites, and the final part is to develop an innovative nanocomposite which has superhydrophobic and low moisture permeation properties. We have found that when the concentration of nanoparticles reaches its percolation threshold, the glass transition temperature of nanocomposite which can not be measured by to conventional macroscale thermal analytic instruments such as DSC and TMA. Therefore, we have established a methodology basis on in-situ thermal atomic force microscope to monitor the nanophase transition of the nanocomposite upon heating. When the concentration of nanoparticles reaches its percolation threshold, a dramatic increasing in thermal and mechanical properties that is universal regardless the chemical structure of polymers and the particles of the nanoparticles in the nanocomposite. Finally, we synthesize a fluoroimide acrylate as an organic component of nanocomposite, then add silica nanoparticles to reinforce the thermal stability and mechanical properties of polymer to develope a solventless photocurable nanocomposite resin system. To control the size of nanodomain can make materials have the superhydrophobic, and fluoroimide acrlate make materials have very low water vapor permeation. It has potential application in optical waveguides, light emitting diodes, device encapsulation, dental restorative materials and so on.

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41

Wu, Po-Shuan, et 吳博軒. « Preparation and Physical Properties of Melamine Polyphosphate/Montmorillonite/Nylon 6 Nanocomposites ». Thesis, 2013. http://ndltd.ncl.edu.tw/handle/9jf5up.

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碩士
國立中興大學
化學工程學系所
101
In this study, melamine polyphosphate (MPP) was prepared and served as Clay modifier. The montmorillonite (MMT) with the characteristics of negative surface charge was modified by MPP via chemical reactions in the aqueous solution. The modified montmorillonite (MPP/Clay) was further introduced to Nylon 6 matrix by melt blending method. Thermal properties and flame retardant properties of (MPP/Clay)/Nylon 6 nanocomposites were studied. The synthesis of MPP was performed by the combination of melamine with phosphoric acid. Melamine phosphate (MP) was first prepared with positive charge in surface that can serve as the modified Clay precursor. After 300 ℃ thermal treatment, the MP molecules went through dehydration polymerization to generate MPP. Fourier transform infrared spectroscopy (FT-IR) indicated melamine polyphosphate wereobserved at 3133.8 cm-1 and 2843.7 cm-1 assigned to the vibration absorption of -NH3+, 2696.7 cm-1assigned to the vibration absorption of O-H groups, 1385.4 cm-1 assigned to the vibration of C-N groups of the triazine rings, 1282.12 cm-1 and 1178.8cm-1 assigned to the vibration of P=O bonds, 970.2cm-1 assigned to the vibration absorptions of P-O in P-O-H groups, and 888.7 cm-1 assigned to the vibration of P-O-P bonds. The modified montmorillonite (MPP/Clay) was prepared via melamine acidification and adsorb on the MMT surface firstly. Next, phosphoric acid was added to generate MP on the Clay surface. It was observed that the increase of MP concentration could further increase the platelet distance to the extent of featureless XRD pattern (none of peaks). The generated MPP particles with diameter less than 100 nm immobilized on the MMT surface was observed by field emission scanning electronic microscopy (FE-SEM). After melt blending, the (MPP/Clay)/Nylon 6 nanocomposites were prepared. Differential scanning calorimetry (DSC) results indicated that modified MMT does not affect the melting point of the polymer matrix. Found that the crystallization temperature of the composites occurred early in the first cooling, add modified montmorillonite has heterogeneous nucleation. Thermogravimetric analysis (TGA) showed that the incorporation of modified MMT (30 wt%) significantly enhanced the residue to 19.53 wt% at 800 ℃. Furthermore, LOI (limiting oxygen index) value increases from 25.3 to 37.4 indicating that (MPP/Clay)/Nylon 6 nanocomposites possess excellent flame retardant properties. FESEM analysis can be observed that the post-combustion of the (MPP/Clay)/Nylon 6 nanocomposites forms compact coke layer structure, thus prevents the inner polymer burning further to achieve the derived flame retardant purpose.

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42

Chen, Shin-Liang, et 陳信良. « Study on Synthesize and Physical Properties of Polyurethane/Carbon Nanotube Nanocomposites ». Thesis, 2005. http://ndltd.ncl.edu.tw/handle/72365708694836894285.

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碩士
國立雲林科技大學
工業化學與災害防治研究所
93
The preparation of polyurethane (PU)/Carbon nanotube(CNT) nanocom- posites is main class in the study. With Increasing dispersion of CNT in the matrix by CNT functionalization to improve thermal、mechanical and electric properties of nanocomposites. Interfacial interaction of CNT and PU have been investigated by FTIR spectroscopy. Insight into the nature of CNT dispersion was gained by AEM、FE-SEM and AFM inspection. Thermal properties analyze by DSC and the analysis of thermal stability perform by TGA. The characterization of mechanical and electrical of composites is determined by Tensile and DC Four Probe. The crystallization is measured by X-ray. The result show modified CNT and polymer matrix with interaction to achieve good dispersion in composites film. With increasing the content of CNT , the hard segment Tg increase and become unobvious when reached 20wt%. The residual of composites raise substantially at 600℃. When addition reach 20wt% the Young''s modulus and tensile strength is enhanced by more than 400% and 100% , the electric conductivity with 10-1S/cm. X-ray with the characteristic diffraction peak of CNT. Above report display modified CNT with apparent utility in the nanocomposite.

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43

Chen, Bo-Syuan, et 陳伯璿. « Preparation and Physical Properties of Poly(ethylene terephthalate)/Modified Montmorillonite Nanocomposites ». Thesis, 2010. http://ndltd.ncl.edu.tw/handle/44263331262318565689.

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44

Chan, Tzu-Jung, et 詹茲戎. « Preparation and Physical Properties of Poly(ethylene terephthalate) / Carbon Nanotube Nanocomposites ». Thesis, 2010. http://ndltd.ncl.edu.tw/handle/22764813281552062115.

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碩士
國立中興大學
化學工程學系所
98
In this study, the multi-walled carbon nanotube (CNT) was modified to prepare PET/CNT nanocomposites by melt blending. The CNT was adsorbed with a modified silane (MS), and then tetraethylorthosilicate (TEOS) was added to form silica on the CNT surface. Then, the reaction of methacryloxypropyltrimethoxysilane (MPS) on the SiO2/CNT was done to bring the active C=C function group. Finally, styrene and glycidyl methacrylate (GMA) were added and polymerized on SiO2/CNT surface. The epoxy functional group of GMA may react with the carboxylic acid group of PET to improve dispersibility. The adsorption isotherm of MS on CNT was studied, and the capacity of carboxyl of acid on CNT was evaluated as 5.19×10-4 mol/g-CNT. Three kinds of MS weight ratio with 0.038-fold, 0.05-fold and 0.5-fold to CNT were added for the preparation of SiO2/CNT. The Si-O-Si stretching from SiO2/CNT is revealed by FTIR. The Si/C atomic ratio of SiO2/CNT increases with the increase of TEOS as measured by Energy Dispersive X-ray Spectroscopy (EDS). SiO2 nanoparticles on the CNT surface were observed by FESEM. The C=C stretching belonging to MPS, grafted on silica, is confirmed by FTIR. For surface modification, styrene and GMA were added to obtain modified CNT. The characteristic peak of styrene and GMA is observed from FTIR. Furthermore, PET / modified CNT nanocomposites were prepared by melt blending. The interfacial interaction between modified CNT and PET is better than virgin CNT observed by FESEM. The percolation threshold decreases when the weight ratio of MS to CNT increases as determined by electrical conductivity measurement. It is obvious that the added CNT or modified CNT can serve as a good nucleating reagent for PET and accelerates the rate of crystallization. When decreasing the weight ratio of MS to CNT, the storage modulus (E’) of composites increases based on DMA data. In particular, when the weight ratio of MS to CNT is 0.038, the E’ is enhanced by 52% with a 5 phr of modified CNT. Also, adding the modified CNT can increase Tg of PET composites. This is explained by the confinement of dispersed polymer chains by modified CNT and limits their segmental motions.

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45

Ye, Wei-Bin, et 葉偉斌. « Studies on the polymer electrolytes nanocomposites of Synthesis and physical properties ». Thesis, 2002. http://ndltd.ncl.edu.tw/handle/80902479492341716006.

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碩士
元智大學
化學工程學系
90
In order to enhance the compatibility and dispersion of layered double hydroxide (LDH) into the poly(ethylene oxide) (PEO) matrix, the layer surface of LDH was grafted with PEO-oligomer by in-situ synthesis. The obtained PEO/LDH nanocomposites mixed with lithium percolate (LiClO4) can be used as all solid-state polymer electrolytes in the secondary lithium batteries. In this research, the preparation of PEO/LDH nanocomposites was performed to study the effect of LDH on the morphology, conductivity, and ion transport of polymer electrolytes. According to the XRD results, the PEO-oligomer modified LDH shows fully exfoliation dispersion in the PEO matrix. The well dispersed LDH layers in PEO/LDH nanocomposites results in an amorphous morphology, which can be attributed to the improvement of ionic conductivity of nanocomposites without any liquid plasticizer. The highest ionic conductivity of 6´10-5 S/cm (at 30℃) occurs at the composition of 10 wt% LDH added. On the other hand, the lithium ion transference number measured by dc polarization in PEO/LDH nanocomposites increases with increasing LDH amounts, which is attributed to the positive-charge characteristics appearing on the surface of LDH layers.

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46

Wang, Ying-Da, et 王英達. « Synthesis and Physical Properties of UV Curable Liquid-Crystalline Acrylate Nanocomposites ». Thesis, 2010. http://ndltd.ncl.edu.tw/handle/04392332166737991307.

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碩士
臺灣大學
材料科學與工程學研究所
98
In this research, we have synthesized and utilized a liquid crystalline(LC) acrylate, 4,4''-bis(3-Hydroxy- alkyloxy) biphenyl diacrylates(B3A). We have photo cured the B3A either at LC state or at isotropic state and compared the difference of cured properties between two state. Hardness of the sample with LC structure after photocure exhibits 20% higher than the amorphous one. The result is due to the self reinforcing effect from the LC structure remained in the sample after cured. We further improved the physical properties of the B3A by incorporating nanofiller to from nanocomposite. We studied the effect of nanofiller on the formation of LC state in the cured sample. In the first part of this work, we added SiO2 particle which modified with 3-(Trimethoxysilyl) propylmethacrylate (MPS) in acrylate resin. SiO2 enhances its decomposition temperature (Td), storage modulus and glass transition temperature (Tg) effectively. But when the content of SiO2 is further increased, the increase in mechanical property is less significant. In the XRD study, the peak of LC structure is broader as increasing the content of SiO2. It shows that the increased amount of SiO2 decrease the domain size of LC structure. In the second part, nanofillers with different aspect ratios, TiO2 nanorod(TNR) and TiO2 nanoparticle(TNP) are added to acrylate resin to investigate their effect on the LC structure formation and self-reinforcing effect. In TNR nanocomposite series, when we increase TNR contain to 2wt%, that is difficult to find large domain LC structure under POM analysis. Due to the increased amount of TNR limit the formation of LC structure. The trend in TNP nanocomposite series matched up with the trend in SiO2 composite series, but the effect on the physical properties by TNP is less obvious. In conclusion, we observe that the nanocomposites are dependent on the inorganic nanofiller’s shape and the interface interaction of polymer-inorganic. Additionally, the properties of nanocomposites are also affected by the presence of LC structure.

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47

Chen, Ping-Hui, et 陳鵬輝. « Preparation and Physical Properties of Linear Low Density Polyethylene/Modified Montmorillonite Nanocomposites ». Thesis, 2011. http://ndltd.ncl.edu.tw/handle/96394443714746718178.

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碩士
國立中興大學
化學工程學系所
99
In this study, the linear low density polyethylene ( LLDPE ) , the modified clay, and the compatibilizer of maleic anhydride grafted polyethylene ( PEgMA), were melt blended to prepare the linear low density polyethylene / modified clay nanocomposites together with the physical properties measured for these nanocomposites. The preparation of modified clay is done by the synthesis of the modified silane ( Modified Silane, MS ) , adsorpted to clay, and the adding of tetraethyl orthosilicate ( TEOS ) to generate silica particles on clay. The weight ratios of clay and silica are 1：2 and 1：1. Then 3- (Trimethoxy silyl)-1-propanol methacrylate (MPS) was added to prepare the modified clay with grafting . By using CTAB, Styrene, GMA, and KPS we proceed the surface polymerization. By FT-IR analysis, the modified clay with the epoxy groups in GMA on grafted silica has the absorbance at 910 cm-1. This confirmed the successful grafting of GMA onto the modified clay. By XRD analysis, the modified clay shows no diffraction peaks between 1.5 ° ~ 8 °. Linear low density polyethylene / modified clay composites, by XRD analysis, show no diffraction peaks between 1.5 °~8 °. The interfacial strength among clay, silica and LLDPE were improved in the 5.20 phr of modified clay of composites, which was observed by fracture surface in the FESEM analysis. By DSC analysis, LLDPE/clay nanocomposites show similar melting point compared with that of LLDPE. By TGA analysis, the content of modified clay nanocomposites (MMT：SiO2 = 1：1) with 2.60 phr at 10 % weight loss shows a higher temperature of 5.5 ℃ above. In DMA analysis, the composites with the modified clay (MMT：SiO2 = 1：1) also enhance the storage modulus (at 40 ℃) from 1.52×108 Pa to 3.74×108 Pa for the content of 5.22 phr. The data of tensile strength for the modified clay nanocomposite (MMT：SiO2 = 1：1) with a content of 8 phr also improve. The Young''s Modulus improved significantly by 98.8 %. In water permeation analysis, the modified clay nanocomposites (MMT：SiO2 = 1：1) with a content of 5.22 phr shows the water vapor transmission rate decreased by 26.9 %. In oxygen permeation, the modified clay nanocomposite (MMT：SiO2 = 1：1) with a content of 5.22 phr gives a lower oxygen transmission rate by 18.6 %

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48

Chen, Ko-Vin, et 陳科文. « The Manufacture of Polyurethane/Clay Nanocomposites and their Physical and Dyeing Properties ». Thesis, 2005. http://ndltd.ncl.edu.tw/handle/61240914168028303110.

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碩士
逢甲大學
紡織工程所
93
The paper is using the polyurea prepolymer, which was synthesized from the extender (ethylene diamine (EDA) or N-(2-hydroxyethyl) ethylene diamine (HEDA)) and 4,4’-diphenylmethane diisocyanate (MDI), as an intercalative agent to intercalate the organic modified montmorillonite clay. Then, it is further reacted with the polyurethane prepolymer, which is polymerized from the polytetramethylene glycol (PTMG) and MDI, to proceed the intercalative polymerization to form a polyurethane/clay nanocomposite polymer. The experimental parameters contain the molecular weight of polyurea intercalative prepolymer extender and also the contents of organo-clay in the prepolymer etc. We expect to get better mechanical, thermal properties and also improving the dyeing properties of nano-clay polyurethane. 　　The polyurethane/clay polymer is synthesized using two-step method: synthesizing the polyurethane prepolymer from PTMG and MDI and then extended with the polyurea prepolymer modified with the organo-clay. Since the extender HEDA contains side chain of hydroxyl groups, the modified PU can further react with the reactive dye. 　　From the experimental results of qualitative analysis by the fine structure (X-ray and FT-IR) , thermal stability and mechanical analysis. It was found from the X-ray scanning analysis that the intercalation was successfully achieved. The distance of interlayer spacing was manifestly enlarged. From the infrared spectrum analysis (FT-IR) , the polyurethane and the polyurethane/clay nanocomposites were successfully synthesized. Thermal stability was improved as the content increased. The mechanical properties were significantly improved as the content of organo-clay was increased. For the dyeing properties, the dye-uptake was lowered down as the amount of organoclay increased, but the dye-fastness was increased up to grade of 5.

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49

Chein, Ching-Foun, et 簡正豐. « The Study of Interfacial Modification on Physical Properties of Polystyrene/Montomrillonite Nanocomposites ». Thesis, 2000. http://ndltd.ncl.edu.tw/handle/17694641383439222980.

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碩士
國立中興大學
化學工程學系
88
Abstract This thesis is aimed at surface modification of Montmorillonite (MMT) by coating styrene-acrylate copolymer via surface polymerization. We tried improve the adhesion between MMT and styrene-acrylate copolymer by the interaction between carbonyl polar group of acrylate and polar of MMT. These modified MMT platlets were easily dispersed and swollen in styrene monomer. Polystyrene-clay nanocomposites were prepared through bulk polymerization . Cetyltrimethyl ammonium bromide (CTAB) was used to perform the ion-exchange with Na+ on MMT surface and to form admicelle on MMT surface. The adsolubilization of styrene and methyl methacrylate into CTAB bilayers (admicelles) adsorbed on MMT was measured by HPLC. Results showed that the adsolubilization constant of styrene was 800M-1 which was nearly constant despite varying equilibrium concentration of styrene in the aqueous phase. While the adsolubilization constant of methyl methacrylate decreased with increasing equilibrium concentration . In the mixed monomer system , adsolubilization constants for styrene and methyl methacrylate were all decreased with increasing monomer equilibrium concentration in the aqueous phase. Samples after surface polymerization were analyzed with respect to the d-spacing by X-ray diffraction (XRD) and glass transition temperature by DSC. The molecular weight of copolymer formed on MMT was measured with GPC/light scattering. The PS/MMT nanocomposites contained 1 wt% and 3 wt% MMT in the polystyrene matrix were prepared. X-ray diffraction (XRD) and transmission electron microscopy (TEM) indicated the exfoliation of MMT in polystyrene. Some local areas appeared to contain a bundle of 2-6 parallel silicate layers with basal spacing equals to 3-4 nm that is consistent with the XRD analysis. Also , these nanocomposites were analyzed by DMA for measuring storage modulus (E'') , loss modulus (E") and loss factor (tanδ). The storage modulus of nanocomposites containing 3 wt% MMT modfied by styrene-acrylate copolymer was 1.4 times that of polystyrene without clay. For MMT modified by poly(styrene-methyl methacrylate) copolymer, storage modulus and loss modulus were 1.2 times that of MMT modified by polystyrene. In this research, we have prepared PS/MMT nanocomposites with good mechanical properties through surface copolymerization of styrene and acrylate on MMT to enhance the interfacial bonding between polystyrene and MMT.

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50

Liau, Jeng-Jia, et 廖政佳. « The synthesis and Physical properties of Anionic Water-borne Polyurethane/Clay Nanocomposites ». Thesis, 2005. http://ndltd.ncl.edu.tw/handle/14686635950081551964.

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碩士
逢甲大學
紡織工程所
93
Polyurethane can usually be syntheized by polydiol ，diisocynate and extender (diol or diamine ) , and its property can also be affected by its composition. In this research, first we discuss the mechanical property of polyurethane influenced by molecular weight of extender. Select a better molecular weight and add different kinds of nanoclays to it , and form the polyurethane/clay nanocomposites. Compared the thermal stability and mechanical properties with different kinds of nanoclays for polyurethane/clay nanocomposites. then, we choose the better one (compatibility and dispersibility) and discuss the thermal stability and mechanical properties of polyurethane/clay nanocomposites with different content of the nanoclay. Finally dyeing it by reactive dye. Discuss the influence of dye to polyurethane/clay with different contents of clay. From the infrared spectrum analysis (FT-IR),we know the polyurethane and the polyurethane/clay nanocomposites has be successfully synthesized ；From the X-ray diffraction spectral analysis, it can be found that the polyurethane/clay nanocomposites d-space was enlarged , the mechanical property of polyurethane/clay was affected by mean molecular weight, the polyurethane with the extender mean molecular weight of 274.5 had better mechanical property. But as the mean molecular weight increased, the mechanical property didn’t increase because of polyurethane phase separation. Therefore the mechanical property didn’t increase with mean molecular weight increased. In polyurethane/clay nanocomposites, the clay of 25A was the better one showing good dispersibility , and it also had better mechanical property and thermal stability. Polyurethane/clay nanocomposites with more contents of clay exhibited better mechanical property and thermal stability. The mechanical property was poor as the content over 3%. Nevertheless, the thermal stability was increased with the increasing content of clay. For the dyeing of polyurethane/clay nanocomposites , the dyeing uptake was loss with the addition of nanoclay; but the colorfastness to water was increased with the addition of nanoclay.

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Thèses sur le sujet « Nanocomposites - Physical Properties »

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