Дисертації з теми "Polyethylene nanocomposites"
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Green, Christopher Duncan. "Polyethylene-montmorillonite nanocomposites." Thesis, University of Southampton, 2008. https://eprints.soton.ac.uk/65001/.
Повний текст джерелаIsik, Fatma. "Nanocomposites Based On Blends Of Polyethylene." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/3/12606338/index.pdf.
Повний текст джерелаas organoclay Cloisite&
#61666
15A, Cloisite&
#61666
25A and Cloisite&
#61666
30B were used. All samples were prepared by a co-rotating twin screw extruder, followed by injection molding. Before producing the ternary nanocomposites, in order to determine the optimum amount of the organoclay and compatibilizer, binary mixtures of LDPE/organoclay and LDPE/compatibilizer blends with different compositions were prepared. Based on the results of the mechanical tests, compatibilizer and organoclay contents were determined as 5 wt. % and 2 wt % respectively. After that, ternary nanocomposites were prepared with each compatibilizer/organoclay system and characterization of these nanocomposites was performed. Among the investigated addition orders, mechanical test results showed that the best sequence of component addition was (PCoC), in which LDPE, compatibilizer and organoclay were simultaneously compounded in the first run of the extrusion. Considering the ternary nanocomposites, compositions of LDPE/E-MA-GMA/15A, LDPE/E-GMA/15A and LDPE/E-nBA-MAH/30B showed the highest improvement in mechanical properties. According to the DSC analysis, addition of organoclay and compatibilizer does not influence the melting behavior of the compositions and both compatibilizers and organoclay types have no nucleation activity in LDPE. In the X-Ray analysis, the highest increase of the basal spacing for ternary nanocomposites obtained for LDPE/E-BA-MAH/organoclay nanocomposites. This increase was 83 %, 198 %, and 206 % for samples containing 15A, 25A and 30B respectively.
Shaito, Ali Al-Abed. "Long Term Property Prediction of Polyethylene Nanocomposites." Thesis, University of North Texas, 2008. https://digital.library.unt.edu/ark:/67531/metadc9738/.
Повний текст джерелаAlghamdi, Abdulaziz. "Mechanical characterisation of novel polyethylene-based nanocomposites." Thesis, University of Nottingham, 2014. http://eprints.nottingham.ac.uk/14120/.
Повний текст джерелаBAFNA, AYUSH ASHOK. "POLYETHYLENE-CLAY NANOCOMPOSITES: PROCESSING-STRUCTURE-PROPERTY RELATIONSHIP." University of Cincinnati / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1083810121.
Повний текст джерелаShaito, Ali Al-Abed D'Souza Nandika Anne. "Long term property prediction of polyethylene nanocomposites." [Denton, Tex.] : University of North Texas, 2008. http://digital.library.unt.edu/permalink/meta-dc-9738.
Повний текст джерелаBafna, Ayush A. "Polyethylene-clay nanocomposites processing-structure-property relationship /." Cincinnati, Ohio : University of Cincinnati, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=ucin1083810121.
Повний текст джерелаChan, Hong Yu. "Crystallization of polypropylene/vermiculite and polyethylene/vermiculite nanocomposites." access abstract and table of contents access full-text, 2004. http://libweb.cityu.edu.hk/cgi-bin/ezdb/dissert.pl?msc-ap-b21173990a.pdf.
Повний текст джерелаAt head of title: City University of Hong Kong, Department of Physics and Materials Science, Master of Science in materials engineering & nanotechnology dissertation. Title from title screen (viewed on Aug. 31, 2006) Includes bibliographical references.
Al-Fouzan, Abdulrahman M. "Polyethylene Terephthalate / clay nanocomposites. Compounding, fabrication and characterisation of the thermal, rheological, barrier and mechanical properties of Polyethylene Terephthalate / clay nanocomposites." Thesis, University of Bradford, 2011. http://hdl.handle.net/10454/5283.
Повний текст джерелаKarlsson, Mattias. "Investigation of the dielectric breakdown strength of polymer nanocomposites." Thesis, Uppsala universitet, Tillämpad materialvetenskap, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-227815.
Повний текст джерелаCapaldi, Franco Mario 1977. "Atomistic simulations of octacyclopentyl polyhedral oligomeric silsesquioxane polyethylene nanocomposites." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/32388.
Повний текст джерела"June 2005."
Includes bibliographical references.
As the scientific community develops the ability to create composites which incorporate nanoscopic filler particles, the detailed atomic arrangement and atomic interactions become significant in determining the composite properties. Nanoscopic fillers such as carbon nanotubes, polyhedral oligomeric silsesquioxane (POSS), and layered silicates have already been successfully used to improve the thermal and mechanical properties of polymers. On this length scale, details describing particle organization, interaction between particles, and interactions between particle and matrix are needed to understand the behavior of the composite. In this thesis, we use atomistic simulations to investigate the detailed behavior of a blended octacyclopentyl polyhedral oligomeric silsesquioxane (CpPOSS) / polyethylene (PE) nanocomposite. The model potential employed to describe the atomic interactions in these systems is capable of reproducing the experimental vibrational and crystal structures for the POSS well. The mechanical properties of an infinite crystal were calculated. The), are anisotropic with a Reuss average isotropic elastic modulus of 11.78 GPa. Simulations of CpPOSS/PE composites revealed that the POSS had a stiffening effect on the polymer. Simulations revealed that both PE and POSS dynamics as measured by translational and rotational diffusivities decreased, the glass transition temperature increased, and both the density and modulus increased with increasing POSS content. Micromechanical models were fit to the composite modulus which allowed effective mechanical particle sizes to be determined.
(cont.) The POSS was found to aggregate into small necklace structures which have internal ordering similar to the crystal phase. The formation of crystallites was found to be energetically favorable in this system. A coarse grained potential which accounts for both the attraction and orientation between particles was developed to aid the further study of aggregation and crystallization in these composites. The interface between the POSS and the polymer is found to consist of polymer chains aligned tangentially to the POSS cage. This layer has increased mobility tangential to the surface of the particle and decreased mobility in the radial direction. Though it is very thin, consisting of only 1 or 2 monolayers of polymer, due to the small size of the POSS particle, the weight fraction of polymer in the interfacial region is as high as 43 % in the 25 weight percent CpPOSS/PE composite. These simulations reveal the formation of structure on both the angstrom length scale in the polymer near the interface and the mesoscopic length scale between the POSS particles.
by Franko M. Capaldi.
Ph.D.
Lau, K. Y. "Structure and electrical properties of silica-based polyethylene nanocomposites." Thesis, University of Southampton, 2013. https://eprints.soton.ac.uk/358889/.
Повний текст джерелаOluz, Zehra. "Additives For Photodegradable Polyethylene." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614537/index.pdf.
Повний текст джерелаTang, Youhong. "Microrheological study on polyethylene/thermotropic liquid crystalline polymer/layered silicates nanocomposites /." View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?CENG%202007%20TANG.
Повний текст джерелаReading, Martin. "An investigation into the structure and properties of polyethylene oxide nanocomposites." Thesis, University of Southampton, 2010. https://eprints.soton.ac.uk/171659/.
Повний текст джерелаGill, Yasir Q. "Preparation and characterization of polyethylene based nanocomposites for potential applications in packaging." Thesis, Loughborough University, 2015. https://dspace.lboro.ac.uk/2134/18052.
Повний текст джерелаTraina, Matteo. "Preparation and properties of micro- and nanocomposites based on high density polyethylene." Doctoral thesis, Università degli studi di Trento, 2008. https://hdl.handle.net/11572/368262.
Повний текст джерелаTraina, Matteo. "Preparation and properties of micro- and nanocomposites based on high density polyethylene." Doctoral thesis, University of Trento, 2008. http://eprints-phd.biblio.unitn.it/105/1/TRAINA-Matteo_PhD-thesis-2008_200DPI.pdf.
Повний текст джерелаChen, Jia. "Modified Yttrium Hydroxide/MC Nylon Nanocomposites and Scaling Effects in Multilayer Polyethylene Films." Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6073.
Повний текст джерелаKosuri, Divya. "Polyethylene-layered double hydroxide and montmorillonite nanocomposites: Thermal, mechanical and flame retardance properties." Thesis, University of North Texas, 2008. https://digital.library.unt.edu/ark:/67531/metadc6087/.
Повний текст джерелаLabde, Rohan Khushal. "Preparation and Characterization of Polyethylene Terephthalate/Montmorillonite Nanocomposites by In-situ Polymerization Method." University of Toledo / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1271126238.
Повний текст джерелаKosuri, Divya D'Souza Nandika Anne. "Polyethylene-layered double hydroxides and montmorillonite nanocomposites thermal, mechanical and flame retardance properties /." [Denton, Tex.] : University of North Texas, 2008. http://digital.library.unt.edu/permalink/meta-dc-6087.
Повний текст джерелаKanbur, Yasin. "Conductive Polymer Nanocomposites Of Polypropylene And Organic Field Effect Transistors With Polyethylene Gate Dielectric." Phd thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613312/index.pdf.
Повний текст джерелаs and fullerenes were surface functionalized with HNO3 : H2SO4 before composite preparation. The CNT and fullerene content in the composites were varied as 0.5, 1.0, 2.0 and 3.0 % by weight. For the composites which contain surface modified CNT and fullerene four different compatibilizers were used. These were selected as TritonX-100, Poly(ethylene-block-polyethylene glycol), Maleic anhydride grafted Polypropylene and Cetramium Bromide. The effect of surface functionalization and different compatibilizer on mechanical, thermal and electrical properties were investigated. Best value of these properties were observed for the composites which were prepared with maleic anhydride grafted polypropylene and cetramium bromide. Another aim of this study is to built and characterize transistors which have polyethylene as dielectric layers. While doing this, polyethylene layer was deposited on gate electrode using vacuum evaporation system. Fullerene , Pentacene ve Indigo were used as semiconductor layer. Transistors work with low voltage and high on/off ratio were built with Aluminum oxide - PE and PE dielectrics.
Nawaz, Sohail. "Preparation and long-term performance of poly(ethylene-co-butyl acrylate) nanocomposites and polyethylene." Doctoral thesis, KTH, Polymera material, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-104685.
Повний текст джерелаQC 20121109
Cable insulation materials
Loss of deltamethrin and pipronyl butoxide from polyethylene
long-term performance of polyethylene in chlorine dioxide water
Isik, Coskunses Fatma. "Ternary Nanocomposites Of Low Density,high Density And Linear Low Density Polyethylenes With The Compatibilizers E-ma_gma And E-ba-mah." Phd thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613294/index.pdf.
Повний текст джерелаMethyl acrylate &ndash
Glycidyl methacrylate terpolymer (E-MAGMA) and Ethylene &ndash
Butyl acrylate- Maleic anhydrate terpolymer (E-BA-MAH) were used as the compatibilizers. The organoclays selected for the study were Cloisite 30B and Nanofil 8. Nanocomposites were prepared by means of melt blending via co-rotating twin screw extrusion process. Extruded samples were injection molded to be used for material characterization tests. Optimum amounts of ingredients of ternary nanocomposites were determined based on to the mechanical test results of binary blends of PE/Compatibilizer and binary nanocomposites of PE/Organoclay. Based on the tensile test results, the optimum contents of compatibilizer and organoclay were determined as 5 wt % and 2 wt %, respectively. XRD and TEM analysis results indicated that intercalated and partially exfoliated structures were obtained in the ternary nanocomposites. In these nanocomposites E-MA-GMA compatibilizer produced higher d-spacing in comparison to E-BA-MAH, owing to its higher reactivity. HDPE exhibited the highest basal spacing among all the nanocomposite types with E-MA-GMA/30B system. Considering the polymer type, better dispersion was achieved in the order of LDPE<
LLDPE<
HDPE, owing to the linearity of HDPE, and short branches of LLDPE. MFI values were decreased by the addition of compatibilizer and organoclay to the matrix polymers. Compatibilizers imparted the effect of sticking the polymer blends on the walls of test apparatus, and addition of organoclay showed the filler effect and increased the viscosity. DSC analysis showed that addition of compatibilizer or organoclay did not significantly affect the melting behavior of the nanocomposites. Degree of crystallinity of polyethylene matrices decreased with organoclay addition. Nanoscale organoclays prevented the alignment of polyethylene chains and reduced the degree of crystallinity. Ternary nanocomposites had improved tensile properties. Effect of compatibilizer on property enhancement was observed in mechanical results. Tensile strength and Young&rsquo
s modulus of nanocomposites increased significantly in the presence of compatibilizers.
Costa, Francis Reny. "Mg-Al Layered Double Hydroxide: A Potential Nanofiller and Flame-Retardant for Polyethylene." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2007. http://nbn-resolving.de/urn:nbn:de:swb:14-1195481811992-27563.
Повний текст джерелаKim, Sung-gi. "PET Nanocomposites Development with Nanoscale Materials." Connect to Online Resource-OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1178043237.
Повний текст джерелаTypescript. "Submitted as partial fulfillment of the requirements for The Doctor of Philosophy Degree in Engineering." Bibliography: leaves 200-205.
Svensson, Sofie. "Reprocessing and Characterisation of High Density Polyethylene Reinforced with Carbon Nanotubes." Thesis, Högskolan i Borås, Akademin för textil, teknik och ekonomi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-12853.
Повний текст джерелаNanocomposite containing High Density Polyethylene (HDPE) and Carbon Nanotubes (CNTs)was reprocessed and characterised to investigate the effect on properties during recycling. Thecomposite was prepared with 3 wt-% CNTs and was recycled ten times by alternatereprocessing and grinding and thereafter the material was characterised. Furthermore, simulatedcycles with continuous processing at 20, 100 and 200 minutes were conducted, representing 10,50 and 100 cycles respectively, in order to investigate the degradation after longer time ofprocessing. In both trials, a reference material containing neat HDPE was studied. Thecharacterisation of the materials produced was conducted using tensile, flexural and charpyimpact testing for investigation of mechanical properties. Differential Scanning Calorimetry(DSC) was used for determining the thermal behaviour and Gel Permeation Chromatography(GPC) to find molecular weight changes. Fourier Transform Infrared Spectroscopy (FTIR) wasused for identification of the material. The results showed no major difference in propertiesafter ten recycling steps, which indicated that the material had the ability to retain its propertiesduring recycling. In the simulated cycles, the oxidative induction time was decreased after 50and 100 cycles, meaning that antioxidants had been consumed during processing. After 50cycles the molecular weight for the reference material was slightly decreased and after 100cycles significantly decreased, indicating chain scission of the polymer chains. For thecomposite the molecular weight was stable, due to that the carbon nanotubes protect thepolymer matrix during degradation.
Zhang, Qilei. "Preparation of high-strength and high-modulus HA/UHMWPE nanocomposites for cortical bone replacement /." View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?CBME%202008%20ZHANG.
Повний текст джерелаVaddi, Satya. "Flammability evaluation of glass fiber reinforced polypropylene and polyethylene with montmorillonite nanoclay additives." Birmingham, Ala. : University of Alabama at Birmingham, 2008. https://www.mhsl.uab.edu/dt/2009r/vaddi.pdf.
Повний текст джерелаTitle from PDF title page (viewed Feb. 1, 2010). Additional advisors: Derrick R. Dean, Gregg M. Janowski, Selvum (Brian) Pillay (ad hoc). Includes bibliographical references (p. 76-82).
Bueno, Marcos Roberto Paulino. "Materiais nanoestruturados sintéticos tipo esmectitas: sua síntese, caracterização e aplicação em nanocompósitos de polietileno." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2008. http://hdl.handle.net/10183/24325.
Повний текст джерелаNanostructured natural materials, as smectites, have been widely used in polymeric nanocomposites, with significant gains in many properties. However, due to its polar nature, the use in nanocomposites of polyolefins presents a series of drawbacks. Among these problems, its difficulty exfoliation in the matrix, which generally results in a system not nanostructured and, consequently, with little or no gain on properties. To try to resolve this problem, materials type smectite have been modified with quaternary ammonium salts. These salts, in turn, have toxic characteristics, preventing its use in food packaging. In order to study a new alternative that bypasses these problems, two lamellar nanostructured materials, like smectite, with alkyl groups containing sigma links connected to lamellar inorganic network, were synthesized. Both materials had excellent mesostructural order. One of the synthesized materials, formed by a lamellar Al-silsesquioxane, containing high levels of alkyl chain between the inorganic lamella, was used in the formation of a polyethylene composite. Commercial natural clay, modified with quaternary ammonium salts (Cloisite 15A), was used for comparative purposes. The composites then obtained, were characterized to assess microstructural differences, morphological change, and its mechanical and rheological properties. Comparatively to commercial clay (Cloisite 15A), the composites containing synthetic materials, showed differented rheologics properties, better impact resistance and better Environmental Stress Cracking Resistance (ESCR).
Ersu, Dilek. "Preparation And Characterization Of Nanocomposites With A Thermoplastic Matrix And Spherical Reinforcement." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/3/12607447/index.pdf.
Повний текст джерелаethylene/n-butyl acrylate/maleic anhydride (E-nBA-MAH), ethylene/glycidyl methacrylate (E-GMA) and ethylene/methyl acrylate/glycidyl methacrylate (E-MA-GMA) Lotader®
resins
as silica Cab-o-sil®
M5 fumed silica were used. All samples were prepared by means of a lab scale co-rotating twin screw extruder and injection molded into standard samples. In the first step, individual effects of filler and compatibilizers were studied in binary systems with LDPE. Then, keeping the amount of compatibilizer constant at 5%, ternary nanocomposites were prepared by adding 2 or 5% of fumed silica using different component mixing orders. Among investigated mixing orders, mechanical test results showed that the best sequences of component addition are FO1 [(LDPE+Co)+M5] and FO2 [(LDPE+M5)+Co] mixing orders. Considering the compatibilizers, E-nBA-MAH terpolymer showed the highest performance in improving the mechanical properties, E-GMA copolymer also gave satisfactory results. According to the DSC analysis, since addition of fumed silica and compatibilizer does not influence the crystallization behavior of the compositions, it is concluded that, neither fumed silica nor any of the compatibilizers have nucleation activity on LDPE. MFI test results showed that, addition of fumed silica increases the melt viscosity, decreasing MFI values of samples. This change seems to be directly proportional to fumed silica amount.
Tijen, Seyidoglu. "Purification And Modification Of Bentonite And Its Use In Polypropylene And Linear Low Density Polyethylene Matrix Nanocomposites." Phd thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612204/index.pdf.
Повний текст джерела3210), were prepared by melt compounding in the batch mixer at two different clay concentrations (2 and 5 wt %) and fixed compatibilizer/organoclay ratio (&alpha
=2.5). A commercial organoclay, I34, was also used in LLDPE based nanocomposites to make a comparison. XRD and TEM analyses of the compounds prepared by DMDA and TBHP showed mixed nanocomposite morphologies consisting of partially intercalated and exfoliated layers. Young`s modulus and tensile strength of nanocomposites prepared with DMDA and TBHP showed generally higher values compared to those of neat LLDPE, while results were the highest in the composites prepared with commercial organoclay I34. Parallel disk rheometry was used as a supplementary technique to XRD, TEM and mechanical characterizations, and it was shown to be a sensitive tool in assessing the degree of dispersion of clay layers in the polymer matrix.
Pallon, Love. "Polyethylene/metal oxide nanocomposites for electrical insulation in future HVDC-cables : probing properties from nano to macro." Doctoral thesis, KTH, Polymera material, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-193591.
Повний текст джерелаNanokompositer av polyeten och metalloxidpartiklar anses vara möjliga material att använda i morgondagens isolationshölje till högspänningskablar för likström. För att nå en transmissionsspänning på 1 MV behövs isolationsmaterial som i jämförelse med dagens polyeten har lägre elektrisk ledningsförmåga, högre styrka mot elektriskt genomslag och som kan kontrollera ansamling av rymdladdningar. De senaste årens forskning har visat att kompositer av polyeten med nanopartiklar av metalloxider har potential att nå dessa egenskaper. I det här arbetet har kompositer av polyeten och nanopartiklar av MgO för elektrisk isolation producerats och karaktäriserats. Nanopartiklar av MgO har framställts från en vattenbaserad utfällning med efterföljande calcinering, vilket resulterade i polykristallina partiklar med en mycket stor specifik ytarea (167m2 g-1). MgO-nanopartiklarna ytmodifierades i n-heptan genom att kovalent binda oktyl(trietoxi)silan och oktadekyl(trimetoxi)silan till partiklarna för att skapa en hydrofob och skyddande yta. Extrudering av de ytmodifierade MgO nanopartiklarna tillsammans med polyeten resulterade i en utmärkt dispergering med jämnt fördelad partiklar i hela kompositen, vilket ska jämföras med de omodifierade partiklarna som till stor utsträckning bildade agglomerat i polymeren. Alla kompositer med låg fyllnadsgrad (1–3 vikt% MgO) visade upp till 100 gånger lägre elektrisk konduktivitet jämfört med värdet för ofylld polyeten. Vid högre koncentrationer av omodifierade MgO förbättrades inte de isolerande egenskaperna på grund av för stor andel agglomerat, medan kompositerna med de ytmodifierade fyllmedlen som var väl dispergerade behöll en kraftig reducerad elektrisk konduktivitet upp till 9 vikt% fyllnadshalt. Den minsta interaktionsradien för MgO-nanopartiklarna för att minska den elektriska konduktiviten i kompositerna fastställdes med bildanalys och simuleringar till ca 800 nm. Den teoretiskt beräknade interaktionsradien kompletterades med observation av en experimentell interaktionsradie genom att mäta laddningsfördelningen över en Al2O3-nanopartikle i en polyetenfilm med intermodulation (frekvens-mixning) elektrostatisk kraftmikroskop (ImEFM), vilket är en ny AFM-metod för att mäta ytpotentialer. Genom att lägga på en spänning på AFM-kantilevern kunde det visualiseras hur laddningar, både injicerades och extraherades, från nanopartiklarna men inte från polyeten. Det tolkades som att extra energinivåer skapades på och runt nanopartiklarna som fungerar för att fånga in laddningar, ekvivalent med den gängse tolkningen att nanopartiklar introducera extra elektronfällor i den polymera matrisen i nanokompositer. Nanotomografi användes för att avbilda elektriska träd i tre dimensioner. Avbildningen av det elektriska trädet visade att tillväxten av trädet hade skett genom bildning av håligheter framför den framväxande trädstrukturen. Håligheterna leder till försvagning av materialet framför det propagerande trädet och förenklar på det sättet fortsatt tillväxt. Bildningen av håligheter framför trädstrukturen uppvisar en analogi till propagering av sprickor vid mekanisk belastning, i enlighet med Griffiths koncept.
QC 20161006
Kanuga, Karnav D. "A FUNDAMENTAL STUDY ON THE NON-LINEAR MECHANO-OPTICAL BEHAVIOR OF POLYETHYLENE NAPHTHALATE, ITS BLENDS WITH POLYETHERIMIDE AND ITS NANOCOMPOSITES." University of Akron / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=akron1138038431.
Повний текст джерелаCoelho, Paulo Henrique da Silva Leite 1985. "Estudo do efeito de compatibilização de argilas organofílicas em blendas imiscíveis de poliamida 6 e polietileno de baixa densidade." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266910.
Повний текст джерелаDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química
Made available in DSpace on 2018-08-16T01:54:01Z (GMT). No. of bitstreams: 1 Coelho_PauloHenriquedaSilvaLeite_M.pdf: 3567481 bytes, checksum: e65ba429faa53dd840da6f11f7155c0e (MD5) Previous issue date: 2010
Resumo: O trabalho descreve a obtenção de nanocompósitos de polietileno de baixa densidade, poliamida 6, polietileno enxertado com anidrido maleico e montmorilonita organofilicamente modificada com o objetivo de estudar o efeito de compatibilização da argila organofílica nas blendas de polietileno e poliamida. Os compostos foram preparados pelo método de intercalação do fundido em extrusora dupla-rosca e os corpos de prova, obtidos por injeção, foram caracterizados por análise térmica dinâmico-mecânica, microscopia eletrônica de varredura, difração de raios-X, microscopia eletrônica de transmissão, calorimetria exploratória diferencial, análise termogravimétrica e teste mecânicos de resistência a tração e ao impacto. As análises térmicas revelaram uma ligeira queda da estabilidade térmica associada ao efeito de degradação do modificador encontrado na argila; o aparecimento de um novo pico de fusão nas curvas de DSC dos nanocompósitos foi associado à formação de uma nova fase cristalina na poliamida 6, causado pela presença da argila. As análises morfológicas revelaram uma adequada homogeneidade nos nanocompósitos e uma redução dos tamanhos dos domínios das duas fases da blenda, de forma que nenhum aglomerado foi observado, o que mostra que houve uma boa dispersão da argila na matriz. As análises estruturais confirmaram esta boa dispersão através da microscopia eletrônica de transmissão (MET) e da difração de raios-X (DRX), que revelaram que a argila teve suas camadas parcialmente intercaladas e/ou esfoliadas em todos os nanocompósitos estudados, e que esta estrutura encontrada proporcionou uma melhora significativa nas propriedades mecânicas dos compostos
Abstract: This work describes the behavior of nanocomposites of polyamide 6 (PA6), low density polyethylene (LDPE) and an organophilic montmorillonite. The compatibilization effect of the orgalophilic clay was studied with and without the presence of a maleic anhydride grafted polyethylene (PE-g-MA). The nanocomposites were prepared by melt intercalation on a twin screw extruder. The samples were prepared by injection molding, and characterized using scanning electron microscopy (SEM), wide-angle X-diffraction (WAXD), dynamic mechanical analysis (DMA), transmission electron microscopy (TEM) and differential scanning calorimeter (DSC). Mechanical properties as tensile strength and impact strength were also evaluated. The thermal analysis showed a slight decrease in thermal stability that was associated with the effect of degradation of the modifier of the clay; the emergence a new melting peak for the Polyamide 6 associated to a new crystalline phase due the clay nucleation effect. The morphologic analysis showed two phases for all systems but a reduction on the particle dimension due the presence of the clay, with low differences by the use of the compatibilizer. Structural analysis confirmed by transmission electron microscopy (TEM) and X-ray diffraction (XRD), which had its clay layers extensive exfoliated, with some small degree of intercalation nanocomposites at all, and that this structure has provided a significant improvement in mechanical properties of compounds
Mestrado
Ciencia e Tecnologia de Materiais
Mestre em Engenharia Química
Carvalho, José Wilson Camilher. "Estudo, caracterização e aplicação de nanocompósitos utilizando poliolefinas funcionalizadas." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266883.
Повний текст джерелаTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química
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Resumo: É apresentada a preparação e a caracterização de nanocompósitos, produzidos a partir da vermiculita e poliolefinas funcionalizadas como matriz polimérica. As poliolefinas foram representadas pelo polietileno de baixa densidade (PEBD) e o polietileno de baixa densidade linear (PEBDL), utilizadas com e sem o anidrido maleico. A vermiculita de origem nacional foi escolhida como fase inorgânica na preparação dos nanocompósitos, devido a sua abundância e o seu baixo custo associado. A interação das matrizes poliolefínicas com a vermiculita foi facilitada pela utilização de agentes de acoplamento, baseados em compostos de amônio, cujos efeitos sobre as propriedades de barreira, ao oxigênio, à umidade, e de retardância de chama dos compostos obtidos são relatados. Foi utilizada como ferramenta de análise a Espectroscopia de Infravermelho com transformada de Fourier (FTIR), para o acompanhamento e caracterização do processo de síntese das organo-vermiculitas. A Difração de Raio X (DRX) foi utilizada tanto para a análise do minério de vermiculita como recebido, quanto para a caracterização dos nanocompósitos utilizando as vermiculitas modificadas com os agentes de acoplamento. Os resultados foram confirmados com a utilização da Microscopia Eletrônica de Transmissão (MET) e a Microscopia Eletrônica de Varredura (MEV), com auxílio da técnica de feixe de íons (FIB). Essas técnicas confirmaram a obtenção de compostos esfoliados, evidenciando a eficiência dos agentes de acoplamento no processo de obtenção dos nanocompósitos, previamente analisados via DRX. A estrutura esfoliada dos compostos obtidos permitiu que fossem conduzidos testes sobre a sua capacidade de barreira ao oxigênio e a umidade, cujos resultados promissores mostraram a possibilidade de serem utilizados como materiais de embalagem. Da mesma forma, a característica esfoliada destes materiais possibilitou o desenvolvimento de testes para o atendimento da área de fios e cabos como isolamento e cobertura de cabos. Com este objetivo, foram analisados os requisitos de retardância de chama e ao aumento da temperatura de degradação, fundamental à preservação da integridade dos cabos durante o ataque das chamas. Este trabalho apresentou de maneira pioneira o processo de produção e utilização da vermiculita nacional, na obtenção de nanocompósitos, desde minério bruto até o produto final e a sua aplicação em casos reais
Abstract: The preparation and characterization of nanocomposites made from vermiculite and functionalized polyolefins as a polymeric matrix is presented. Polyolefins are represented by low-density polyethylene (LDPE) and linear low-density polyethylene (LLDPE), used with and without maleic anhydride. Vermiculite from a national origin was chosen as an inorganic phase in the nanocomposite preparation, due to its abundance and low cost. The interaction of the polyolefin matrixes with the vermiculite was facilitated using coupling agents. The coupling agents used were represented by the ammonium compounds and their effects were reported in the barrier properties to oxygen, humidity and in flame retardance in the produced compounds. As a nanocomposite analysis tool, Fourrier transformed infrared spectroscopy (FTIR) techniques were used, mainly in following and characterizing the organo-vermiculite process. X-ray diffraction (XRD) was used from the analysis of the vermiculite as received to the nanocomposite characterization using coupling agents. These results were confirmed using the transmission electronic microscopy (TEM) and scanning electronic microscopy (SEM), using focused ion beam (FIB), as well. These techniques confirmed the obtainment of exfoliated compounds that reinforced the coupling agents in the nanocomposite obtainment process, previously analyzed by XRD. The exfolied structure of the compounds obtained allowed for barrier-capacity tests. The nanocomposites tested as an oxygen and humidity barrier showed the possibility of being used as packaging materials due to the promising results presented. Likewise, the exfoliated characteristic of these materials enabled the development of tests to meet the needs of the wire and cable area as insulation and cable jacketing. Within this objective, there was the need to focus on the flame retardance requirements and the increase of the degradation temperature, crucial to preserve cable integrity during the flame attack. This work presents, in a pioneering manner, a revision of the production process and utilization of national vermiculite in obtaining the nanocomposite, from its ore to the final product and its application in real cases
Doutorado
Ciencia e Tecnologia de Materiais
Doutor em Engenharia Química
Ferreira, Santos Melo Ana Elisa. "New approaches for the synthesis of high-performance polyolefins reactor nanocomposites and blends." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0032/document.
Повний текст джерелаDespite the remarkable properties of ultra-high molecular weight polyethylene, itsapplication is limited by the difficulties encountered in conventional melt processing duethe high degree of entanglement of the chains.The aim of this work is to develop polyethylene based nanocomposites and in-reactorblends, by in situ polymerization. For this purpose metallocenes and post-metallocenecatalysts were immobilized by different methods on mesoporous silica SBA-15. The poroussystem of this support, with well-defined channels at the nanometric scale, may causeconfinement effects of macromolecular chains and/or potentiate intimate mixing ofpolymer blends.Ethylene polymerization behavior of the homogeneous and the supported systems alongwith the immobilization methodologies used and their effect on the polymerization activityand polymer molar masses were evaluated.A complete characterization of the nanocomposites and blends comprising different aspectsof the materials properties (morphology, crystallinity and homogeneity) was carried out.The thermal and mechanical properties of the final materials were also evaluated.In a general way the polyethylene based nanocomposites and in-reactor blends showedimproved mechanical properties, in terms of elastic modulus, mechanical strength,toughness and creep resistance, when compared with neat polyethylenes. By processing theUHMWPE powders by compression molding, at high pressure and below its meltingtemperature a remarkable increase of the mechanical parameters was obtained.Preliminary results on the preparation of nanocomposites using cellulose nanowhiskershave shown that this approach is feasible and show potential for further development
Mokashi, Vineet V. "Study of Mechanical Properties of Carbon Nanotubes and Nanocomposites by Molecular Simulations." University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1109358015.
Повний текст джерелаCerezo, Frances Therese, and francestherese_cerezo@hotmail com. "Thermal stability and mechanical property of polymer layered graphite oxide composites." RMIT University. Applied Sciences, 2006. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20080627.161157.
Повний текст джерелаAbakar, Adam Omar. "Elaboration, structuration et propriétés rhéologiques de nanocomposites polymères modèles à base de Laponite." Phd thesis, Université du Maine, 2012. http://tel.archives-ouvertes.fr/tel-00756711.
Повний текст джерелаSILVA, Eduardo de Mello. "Obtenção e caracterização de nanocompósitos na forma de filmes planos." Universidade Federal de Campina Grande, 2016. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/1044.
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Capes
O presente trabalho trata da obtenção e caracterização de filmes planos de PEBDL/bentonita com e sem a incorporação de um agente compatibilizante (PE-gMA). Os filmes foram obtidos por extrusão plana e suas propriedades mecânicas, de permeabilidade e térmicas foram avaliadas em função do teor (0 a 5% em massa) e do tipo de carga incorporada. Duas argilas foram utilizadas: a) uma bentonita de origem local (Paraibana) e b) uma argila organofílica comercial importada. A argila paraibana foi purificada e organofilizada antes de ser incorporada à matriz polimérica. As argilas utilizadas foram caracterizadas através da sua capacidade de troca catiônica (CTC), por difração de raios-x (DRX), por espectroscopia no infravermelho por transformada de Fourier (FTIR), análise da composição química por energia dispersiva (EDX), análise granulométrica e por análise termogravimétrica (TGA). Os nanocompósitos obtidos na forma de filmes planos foram caracterizados por DRX, microscopia eletrônica de varredura (MEV), permeabilidade ao vapor de água e aos gases O2 e CO2, propriedades mecânicas, análise termogravimétrica (TGA) e análise da calorimetria exploratória diferencial (DSC). Os filmes de nanocompósitos com compatibilizante apresentaram morfologia intercalada/parcialmente esfoliada e os filmes sem a presença do compatibilizante apresentaram morfologia compatível com a de nanocompósitos intercalados/microcompósitos. Os resultados das propriedades mecânicas mostraram que os filmes preparados com o agente compatibilizante apresentaram propriedades superiores à da matriz pura e às dos outros sistemas preparados. A presença do agente compatibilizante reduziu significativamente a permeabilidade ao vapor de água e a permeabilidade ao gás O2 nos filmes, mas os filmes sem a presença do agente compatibilizante apresentaram aumento desta propriedade quando comparados ao filme de PEBDL puro. As analises térmicas mostraram um aumento discreto da estabilidade térmica para os filmes de nanocompósitos preparados com o agente compatibilizante.
The present work deals with the manufactur and characterization of flat films of LLDPE/bentonite with and without the incorporation of a compatibilizing agent (PE-g-MA). The films were obtained by flat die extrusion and its mechanical, permeability and thermal properties were evaluated in function of clay content (0 to 5% by mass) and clay identity. Two clays were used: a) a local bentonite (from Paraiba) and b) an imported commercial organoclay. The local clay was purified and organophilized before being incorporated into the polymer matrix. The clays were characterized by cation exchange capacity (CEC), x-ray diffraction (XRD), spectroscopy Fourier transform infrared (FTIR), analysis, chemical composition by dispersive energy (EDX), particle size analysis and by thermogravimetric analysis (TG). Nanocomposites obtained as flat films were characterized by XRD, scanning electron microscopy (SEM), water vapor, O2 and CO2 gas permeability, mechanical properties, thermogravimetric analysis (TG) and differential scanning calorimetry (DSC). The nanocomposite films with compatibilizer showed an intercalated/partially exfoliated morphology while the morphology of the films without compatibilizer was compatible with that of intercalated nanocomposites/microcomposites. The mechanical properties of the films prepared with the compatibilizer agent were higher than those of the neat matrix and the other systems prepared. Compatibilizing agent addition significantly reduced water vapor and O2 gas permeability in films, but the films without the presence of the compatibilizer showed an increase of this property when compared to pure LLDPE film. The influence of compatibilizer addition on CO2 permeability was small. Thermal analyzes showed a slight increase of thermal stability for the films of nanocomposites prepared with the compatibilizing agent.
Pirondelli, Andrea. "Production and Electrical Characterization of Low Density Polyethylene-based Micro- and Nano-dielectrics containing Graphene Oxide, Functionalized Graphene and Carbon Black additives." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016.
Знайти повний текст джерелаJordens, Kurt. "Hybrid Inorganic-Organic Materials: Novel Poly(Propylene Oxide) Based Ceramers, Abrasion Resistant Sol-Gel Coatings for Metals, and Epoxy-Clay Nanocomposites. With an Additional Chapter On: Metallocene Catalyzed Linear Polyethylene." Diss., Virginia Tech, 1999. http://hdl.handle.net/10919/30194.
Повний текст джерелаPh. D.
Pitard, Domitille. "Étude de l'organisation à l'état solide et de la dynamique des chaines polymères dans les nanocomposites polyéthylène/POSS." Phd thesis, Université Paris-Est, 2008. http://tel.archives-ouvertes.fr/tel-00461664.
Повний текст джерелаBARBOSA, Renata. "Estudo da modificação de argilas bentoníticas para aplicação em nanocompósitos de polietileno." Universidade Federal de Campina Grande, 2009. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/1818.
Повний текст джерелаMade available in DSpace on 2018-09-26T15:00:31Z (GMT). No. of bitstreams: 1 RENATA BARBOSA - TESE (PPGEP) 2009.pdf: 13292645 bytes, checksum: e1d1eb846f17881cd108a8bad8f924ec (MD5) Previous issue date: 2009-06-19
Nanocompósitos de PEAD/argila bentonítica modificada e sem modificação foram preparados por meio do processo de intercalação por fusão. Realizou-se, previamente um estudo sistemático com quatro sais quaternários de amônio e em três tipos de argilas bentoníticas. Em seguida, fez-se a escolha de um sal quaternário de amônio e de uma argila bentonítica para dar continuidade ao trabalho. A argila escolhida foi organofilizada usando-se diferentes percentuais de sal quaternário de amônio 100%, 125% e 150% baseados na capacidade de troca de cátions (CTC) da argila. Ficou evidente por difração de raios- X (DRX) que os sais foram incorporados à estrutura da argila confirmando assim sua organofilização. Em princípio, todos os sais poderão ser usados para a organofilização da argila e, consequentemente nos sistemas de nanocompósitos PEAD/argila organofílica. Porém, foi verificado que o tipo de ânion presente pode influenciar a estabilidade térmica do sal quaternário de amônio. Os nanocompósitos foram preparados em uma extrusora de rosca dupla contrarrotacional e, em seguida, corpos de prova foram moldados por injeção. Para a avaliação da inflamabilidade dos sistemas foi utilizado o teste de queima na posição horizontal segundo a norma (UL-94HB) e o método do Calorímetro de Cone. O comportamento térmico dos nanocompósitos foi avaliado por temperatura de deflexão térmica (HDT) e termogravimetria (TG). As técnicas de DRX e microscopia eletrônica de transmissão (MET) foram utilizadas para caracterizar a morfologia e analisar o grau de expansão das argilas preparadas bem como o grau de esfoliação dos nanocompósitos. As propriedades mecânicas de tração e impacto também foram analisadas. Para efeito de comparação, determinadas composições foram extrudadas utilizando-se duas configurações de roscas da extrusora ZSK-30 corrotacional, com objetivos de variar as condições de processo e melhorar as propriedades dos nanocompósitos obtidos. Observou-se que o percentual de sal de amônio e o tipo de compatibilizante polar influenciam nas propriedades finais dos nanocompósitos.
High Density Polyethylene (HDPE) nanocomposites containing unmodified and modified bentonite clay were prepared by melt intercalation technique. Initially, four quaternary ammonium salts and three types of bentonitic clays were studied. Afterwards, one type of salt and one type of clay were chosen for the study. The clay was organophilized using 100,125 and 150wt% of quaternary ammonium salt based on cationic exchange capacity (CEC) of the clay. It was evident from the X-ray diffraction (XRD) that the salts were incorporated into the clay structure confirming its organophilization. In general, all salts may be used for clay organophilization and hence, on HDPE/Organophilic clay nanocomposites. However, it was verified that the type of anion present may influence the thermal stability of the quaternary ammonium salt. The nanocomposites were prepared in a counter-rotating twin screw extruder and the samples were prepared by injection molding. For the evaluation of the flammability, horizontal burn (UL-94HB) and cone calorimeter methods were used. The thermal behavior of the nanocomposites was analyzed by Heat Distortion Temperature (HDT) and Thermogravimetry (TG). XRD and Transmission Electron Microscopy (MET) techniques were used to characterize the morphology and analyze the degree of expansion of the prepared clays, and also the degree of exfoliation of the nanocomposites. Mechanical properties (Tensile and Impact strength) were also analyzed. Some compositions were extruded using two screw configurations of ZSK-30 co-rotacional extruder with the aim of improving the properties of the nanocomposites obtained by varying the processing conditions. It was observed that the percentage of the ammonium salt and the type of polar compatibilizer influence the final properties of the nanocomposites.
Edakkara, A. J., J. J. Mathen, J. Sebastian, G. Ramalingam, and G. P. Joseph. "Electrical Behaviour of Polyethylene Vinyl Acetate / ZnO Nanocomposite." Thesis, Sumy State University, 2013. http://essuir.sumdu.edu.ua/handle/123456789/35634.
Повний текст джерелаMathen, J. J., A. J. Augustine, J. Sebastian, J. Madhavan, and G. P. Joseph. "Synthesis and Characterization of Polyethylene Vinyl Acetate / ZnSe Nanocomposite." Thesis, Sumy State University, 2013. http://essuir.sumdu.edu.ua/handle/123456789/35635.
Повний текст джерелаFang, Liming. "Processing of UHMWPE and HA/UHMWPE nanocomposite for biomedical applications /." View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?MECH%202006%20FANG.
Повний текст джерелаUcar, Egemen. "Ternary Nanocomposites Of High Density, Linear Low Density And Low Density Polyethylenes." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608446/index.pdf.
Повний текст джерелаAX8900), as organoclay Cloisite®
15A were used. All samples were prepared by a co-rotating twin screw extruder, followed by injection molding. Considering ternary nanocomposites, highest impact strength results were obtained with 10% compatibilizer plus 2% organoclay
highest yield stress, elastic modulus, flexural strength, flexural modulus were obtained with 5% compatibilizer plus 4-6% organoclay. DSC data indicated that addition of organoclay and compatibilizer did not change the melting point remarkably
on the other hand it affected the crystallinity. The organoclay used had no nucleation effect on polyethylene, and the compatibilizer decreased the crystallinity of the matrix. X-ray diffraction showed that in all ternary nanocomposites and in binary nanocomposite of high density polyethylene with organoclay, layer separation associated with intercalation of the clay structure occurred,. The highest increase of interlayer gallery spacing was obtained with 10% compatibilizer plus 2% organoclay, which were 25%, 28% and 27% for HDPE, LLDPE and LDPE matrices respectively.