Dissertations / Theses on the topic 'Polyimide'
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Gopalanarayanan, Bhaskar. "Analysis of Thermoplastic Polyimide + Polymer Liquid Crystal Blends." Thesis, University of North Texas, 1998. https://digital.library.unt.edu/ark:/67531/metadc279285/.
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Thermoplastic polyimides (TPIs) exhibit high glass transition temperatures (Tgs), which make them useful in high performance applications. Amorphous and semicrystalline TPIs show sub-Tg relaxations, which can aid in improving strength characteristics through energy absorption. The a relaxation of both types of TPIs indicates a cooperative nature. The semicrystalline TPI shows thermo-irreversible cold crystallization phenomenon. The polymer liquid crystal (PLC) used in the blends is thermotropic and with longitudinal molecular structure. The small heat capacity change (ACP) associated with the glass transition indicates the PLC to be rigid rod in nature. The PLC shows a small endotherm associated with the melting. The addition of PLC to the semicrystalline TPI does not significantly affect the Tg or the melting point (Tm). The cold crystallization temperature (Tc) increases with the addition of the PLC, indicating channeling phenomenon. The addition of PLC also causes a negative deviation of the ACP, which is another evidence for channeling. The TPI, PLC and their blends show high thermal stability. The semicrystalline TPI absorbs moisture; this effect decreases with the addition of the PLC. The absorbed moisture does not show any effect on the degradation. The addition of PLC beyond 30 wt.% does not result in an improvement of properties. The amorphous TPI + PLC blends also show the negative deviation of ACP from linearity with composition. The addition of PLC causes a decrease in the thermal conductivity in the transverse direction to the PLC orientation. The thermomechanical analysis indicates isotropic expansivity for the amorphous TPI and a small anisotropy for the semicrystalline TPI. The PLC shows large anisotropy in expansivity. Even 5 wt. % concentration of PLC in the blend induces considerable anisotropy in the expansivity. Thus, blends show controllable expansivity through PLC concentration. Amorphous TPI + PLC blends also show excellent film formability. The amorphous TPI blends show good potential for applications requiring high thermal stability, controlled expansivity and good film formability.
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Cano, Camilo I. "Polyimide Microstructures From Powdered Precursors: Phenomenological and Parametric Studies on Particle Inflation." Akron, OH : University of Akron, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=akron1123710711.
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Dissertation (Ph.D.)--University of Akron, Dept. of Polymer Engineering, 2005."August, 2005." Title from electronic dissertation title page (viewed 09/24/2005) Includes bibliographical references.
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Neuhaus, Herbert John. "Electrical conduction in polyimide." Thesis, Massachusetts Institute of Technology, 1989. http://hdl.handle.net/1721.1/14476.
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MOUANE, KHALID. "Polyimide thin-ply composite." Thesis, Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-70118.
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Mechanical performance of composite structures is influenced by the accumulation of damage from the manufacturing process and throughout the whole service life. For instance, an aircraft is subjected to a combination of mechanical loading and the thermo-oxidative environment from the take-off to the landing. Therefore, this degree project consists of studying the damage initiation and evolution in carbon fibre reinforced polyimide composites and assesses the thickness effect of the laminated composites. After manufacturing, the level of residual thermal stresses occurring at room temperature lead to the occurrence of microcracks in bundles of the quasi-isotropic composites. Further cooling to cryogenic temperature creates new cracks were appearing. This reinforces the conclusion that cracks are created due to thermal stresses. Comparison between a baseline composite made of carbon fibre T650 8-harness satin weave with thermosetting polyimide resin (ply thickness= 190µm) and thin-ply textile laminate made of Textreme carbon fibre IMS65 (ply thickness=83µm) with the same resin shows that the ply thickness has a significant effect on suppressing or delaying the occurrence and the propagation of microcracks after mechanical loading. It is assumed that there are some edge effects leading to different damage state in 90° and ±45° layers.
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Cao, Yuanmei. "Antireflective Polyimide Based Films." University of Akron / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=akron1335501090.
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Dangarwala, Gaurav A. "A model of the change in viscosity of polyimide PMR-15 during cure." Ohio : Ohio University, 1993. http://www.ohiolink.edu/etd/view.cgi?ohiou1175284832.
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Wang, Jia. "Synthesis and properties of polyimide/organo clay and polyimide/polyaniline-modified clay nanocomposites." University of Cincinnati / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1282055379.
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Criss, Jim McRae. "Synthesis, characterization, and study of polyimide processing additives and their effect on polyimide properties." Thesis, Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/20015.
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Bott, Richard H. "Characterization of modified polyimide adhesives." Diss., Virginia Polytechnic Institute and State University, 1988. http://hdl.handle.net/10919/53914.
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An addition polyisoimide prepolymer was modified through the incorporation of metal particles. The response of this metal/polymer composite to mechanical vibrations and the passage of electric current was measured. Model aluminum conductor bar joints containing this material were assembled and exposed to elevated temperatures for extended periods of time while the electrical properties of the composites were monitored. In the most favorable systems, no thermal degradation of the electrical properties was observed. Dynamic mechanical behavior of the metal/polymer composites indicated good adhesion between particles and the matrix and also a broadening of the glass transition region as well as a post Tg dispersion in the temperature spectrum. The adhesive properties of these metal/polymer composites to aluminum were studied and found to be influenced by the loading level of the metal in the composite.
Chemical reactions occurring during the cure of a neat resin sample of the polyisoimide prepolymer were monitored using infrared spectrometry and differential scanning calorimetry. Both the crosslinking and isomerization reactions were found to be apparently first order with the isomerization having a lower activation energy than the crosslinking. Linear, high molecular weight, thermoplastic polyimides and poly(imide-siloxane) homo- and copolymers prepared by bulk and solution thermal imidization were investigated as structural adhesives for titanium. The solution thermal imidization procedure was found to result in favorable adhesive characteristics while the presence of siloxane segments in the polymer backbone improved the resistance of stressed specimens to moisture. Aluminum-sec-butoxide used as a primer was also found to improve the moisture durability of bonds prepared with these materials.Ph. D.
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Rojahn, Martin. "Encapsulation of a retina implant /." [S.l. : s.n.], 2003. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB10378693.
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Sejour, Hensley. "Investigation of Dithiolenes for Propylene/Propane Membrane Separations." Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/19697.
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Polyimide membranes containing nickel dithiolenes were investigated for the separation of propylene and propane. Permeation and sorption experiments were conducted as well thermal property analyses. Results indicate that the dithiolene has an antiplasticizing effect on the polymers studied. Upon addition of the dithiolene there is a subsequent reduction in the permeability coefficient and the permeability selectivity remains relatively unchanged. There is some evidence of increases in solubility selectivity, but a larger decrease in diffusivity selectivity results in a decrease in the permeability selectivity. Investigation of the thermal and mechanical properties of dithiolene-containing films indicates a reduction in fractional free volume as well as the glass transition temperature when compared to the pure polymer. There is also an increase in the modulus of the films upon addition of the dithiolene. The implications of these results and their correlation with antiplasticization are discussed.
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Kaneko, K., T. Hori, E. Nakane, H. Kondo, and T. Mizutani. "Space Charge Behavior of Polyimide Film." IEEE, 2004. http://hdl.handle.net/2237/7209.
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Kioul, Azzedine. "Polyimide ceramers : composition, morphology and properties." Thesis, Loughborough University, 1993. https://dspace.lboro.ac.uk/2134/10592.
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Polyimides have become important materials in the manufacture of a large number of technical products, e.g. varnishes, coatings etc, as they can fulfill a number of requirements. One such requirement is that they have to withstand high temperatures without deterioration of their properties. The work is based on the expectation that the temperature resistance and thermal stability of polyimides can be enhanced by introducing inorganic heat resistant materials, such as silicates, to form hybrid mixtures known as "ceramers". The systems considered in this work are based on linear aromatic polyimides and silica networks produced by the sol-gel route. Solutions of polyamic acid and partially polymerised tetraethoxysilane (TEaS) solutions are converted into ceramer films by solvent evaporation, followed by imidisation and condensation reactions through stepped temperature rises up to a maximum of 350°C. Phase separation is prevented by the use of small amounts of compatibilising agent glycidyloxypropyltrimethoxysilane (GOTMS) or by addition of triethylamine or tributylamine catalysts. By controlling the rate of condensation reactions in the two components different morphologies are obtained, varying from semi-interpenetrating networks of linear poyimides within highly crosslinked silica chains to finely dispersed heterogeneous systems exhibiting etiher a co-continuous or particulate microstructure. As each phase consists of interpenetrating networks of the two components at different concentrations, it is inferred that phase separation takes place through a spinodal decomposition. The crosslinking density of the silica network was reduced by diluting the tetraethoxysilane component with minor quantities of· dimethyldiethoxysilane (DMES). The properties of polyimide ceramers were found to be intermediate between those exhibited by the individual components, depending on the details of the morphological structure. The most interesting characteristics of these systems are: (a) high modulus, high glass transition temperature and dimensional stability at temperatures greater than 250·C, (b) suppression of anisotropy in polyimide films by addition of silica, and (c) negative coefficients of thermal expansion below 100·C. The causes of this anomalous behaviour are not clear at this stage but it appears to be related to large volumetric changes taking place within the silica network as a consequence of the absorption and desorption of small amounts of water.
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Collins, Gustina B. "Laser Processing of Polyimide on Copper." Thesis, Virginia Tech, 2001. http://hdl.handle.net/10919/32559.
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While work using a laser for processing a polymer dielectric is currently being studied, the purpose of this thesis is to present an effective and economical approach using laboratory equipment that is most commonly used and available for the processing of materials including polymers and metals. The use of a laser allows for a more cost effective and flexible method for processing polyimide over other wet and dry processes.
This thesis represents the results of research on the laser processing of polyimide on copper. The research examines the effect of the laser processing parameters using a CO2 laser. The parameters examined include the pulse width, repetition rate, and number of pulses. The processed samples include freestanding Kapton with no adhesive layer, freestanding Kapton with an adhesive layer, and Kapton with adhesive layered on copper. The laser processing used a single laser shot with the parameters being varied over a series of shots fired. The effect of the parameters was observed over large and small ranges. The characteristics of processed freestanding samples were graphically presented along with captured images. The results demonstrate that the laser processing of polyimide is strongly dependent on the laser pulse width and that the optimum value from these experiments suggest the use of a pulse width of 60ms for using a CO2 laser. From these results, further considerations for the laser processing of polyimide on copper were given.Master of Science
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FLAMENT, OLIVIER. "Etude xps des interfaces polyimide/isolant." Paris 7, 1990. http://www.theses.fr/1990PA077034.
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L'etude des interfaces, pour la comprehension des phenomenes d'adherence, entre le polyimide pmda-oda (pyromellitic dianhydride-oxydianiline) et des substrats isolants (al#2o#3 et si#3n#4) est abordee a partir de la technique xps (x-ray photoelectron spectroscopy). Une calibration du spectrometre pour l'obtention de resultats quantitatifs est prealablement effectuee, la methode permettant l'obtention de mesures quantitatives reproductibles qui tiennent compte des conditions operatoires. L'utilisation de depots de polyimide en films minces (<5 nm) a permis de mettre en evidence des differences entre des temps de recuit de 1 h et 5 h a 240#oc au niveau de l'interface polymere-substrat. En effet, parallelement a l'imidisation du polyimide, des variations importantes sont constatees dans le niveau c#1#s (diminution du pic du aux imides, apparition d'un pic supplementaire) et le niveau n#1#s (augmentation de la quantite de liaisons c=n par rapport au polyimide de reference). Ces variations sont attribuees a la formation de liaisons substrat-polymere de type al-o-c pour les substrats d'alumine. Pour les substrats de nitrure, ces changements sont significatifs pour les substrats non traites et traites par plasma o#2, alors que pour ceux ayant subi un traitement d'adherence avec la -aps (-aminopropyltriethoxysilane) aucune difference n'est revelee entre les deux types de recuit. Des tests de pelage ont ete effectues pour les differents cas. Ils mettent en evidence que le recuit prolonge du polyimide (5 h) ameliore l'adherence sur les nitrures non traites ou oxydes par plasma; ceci correlant bien avec la caracterisation par esca de liaisons substrat-polymere
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Panigot, Michael John. "Synthesis and photochemistry of polyimide endcaps." Case Western Reserve University School of Graduate Studies / OhioLINK, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=case1055531066.
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Sekar, Sudalai muthu Suriya. "Characterization of Polyimide/Graphene Hybrid Nanocomposites." University of Cincinnati / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1565348858679907.
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Ellison, Matthew M. "Metal/polymer interactions in polyimide adhesives." Diss., This resource online, 1995. http://scholar.lib.vt.edu/theses/available/etd-08282003-155323/.
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Miller, Larry M. "A model for the prediction of thermo-oxidative mass loss of ceramic coated polyimide composites." Ohio : Ohio University, 1995. http://www.ohiolink.edu/etd/view.cgi?ohiou1174609538.
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Rymer, Dawn Lee. "The atmospheric chemical vapor deposition of titanium nitride on polyimide substrates." Ohio : Ohio University, 1995. http://www.ohiolink.edu/etd/view.cgi?ohiou1179952065.
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Sili, Elyse. "Étude et caractérisation des décharges partielles et du vieillissement du polyimide en environnement aéronautique." Toulouse 3, 2012. http://thesesups.ups-tlse.fr/1922/.
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Les inquiétudes, entretenues d'une part par l'augmentation exponentielle de la consommation des énergies fossiles et d'autre part par le souci de préserver l'environnement, ont motivé les acteurs impliqués dans le domaine du transport à mettre en place des solutions alternatives. Une des solutions possibles est le développement des véhicules plus électriques, voire hybrides. Or le passage vers une nouvelle génération d'avion plus électrique exige l'augmentation de la puissance électrique embarquée qui peut être atteinte tout en préservant la masse embarquée à travers l'augmentation du niveau de tension. Cette augmentation de tension combinée aux contraintes imposées par l'environnement avionique : baisse de pression liée à l'altitude, cycles de température et variation du taux d'humidité, entrainent l'apparition de nouveaux phénomènes qui sont défavorables aux Systèmes d'Isolation Electrique (SIE) tels que les décharges partielles (DP). L'apparition de ces décharges dépend des conditions de fonctionnement et peut conduire à un vieillissement prématuré des matériaux isolants et donc du matériel électrique des systèmes embarqués. C'est dans ce cadre que s'inscrit le travail présenté dans ce manuscrit, dont l'objectif est d'évaluer l'impact des contraintes imposées en environnement aéronautique sur les caractéristiques des décharges et sur le vieillissement des isolants sous décharge. Dans un premier temps, des mesures de caractéristiques de décharges telles que leur seuil d'apparition et l'énergie dissipée en contraintes combinées (P, T, Hr), ont montré la présence de deux mécanismes de claquage qui régissent le développement de la décharge à gauche du minimum de Paschen suivant la valeur de la température appliquée. De plus, une étude menée sur la validité des expressions correctives introduites à la loi de Paschen a démontré leur validité sous pression atmosphérique. Pour des combinaisons de températures et de pressions, une nouvelle formule empirique pour le calcul de la tension de claquage a été proposée et validée pour des températures supérieures à 35°C. Ensuite une étude sur l'impact de l'environnement aéronautique ainsi que d'autres paramètres sur les caractéristiques de la décharge a été abordée. Il a été démontré que ses caractéristiques varient en fonction du paramètre appliquée (T, P, Hr, d, U), et cette variation a été expliquée en se référant au libre parcours moyen des électrons. Enfin, une étude sur l'influence de l'environnement aéronautique sur le comportement de l'énergie dissipée par les décharges et sur le vieillissement du polyimide a été menée, afin de trouver une relation entre ces deux grandeurs. D'après les résultats obtenus, il a paru difficile d'établir une relation directe entre ces deux grandeurs, et valable quelles que soient les conditions appliquées à cause, en particulier, de la variation des propriétés de la surface vieillie en fonction des conditions atmosphériques. Une relation plus pertinente entre la durée de vie et une autre caractéristique de la décharge a été proposée en considérant l'intensité des décharges. Il a été démontré que quelles que soient les conditions appliquées, la durée de vie et l'intensité des décharges sont inversement proportionnellesThe anxiety maintained on one hand by the exceptional increase in the consumption of fossil fuels and on the other hand by the concern for environmental protection has motivated the scientists who work in the transportation domain to find alternative solutions. So the aircraft industry is increasingly shifting towards more electrical technologies. Hence electrical systems with higher powers are required. However, the increase in electrical power demand to supply these alternative electrical systems requires higher voltages. Or increasing the supply voltage combined with the constraints imposed by the avionics environment (pressure drop due to the altitude, temperature cycles and variation of moisture) would introduce others, namely an increased probability of electrical discharge. Unwanted partial discharge (PD) in electrical systems can lead to the deterioration of solid insulation and consequently failure of whole components. The need therefore exists to understand the effect of environmental parameters on the PD characteristics and on the insulation lifetime which is the aim of this work. In the first part, we have been investigating the effect of low pressure combined with high temperature on the partial discharge characteristics as the ignition voltage and the dissipated energy. Results show two different behaviours related to temperature at the left of the Paschen minimum. In an attempt to explain these results, it appears that this effect is related to the presence of two different breakdown phenomena. Then the domain of validity of two corrective expressions on the Paschen's law found in the literature, in case of changing the air environment was investigated. Results show that these corrections are valid under atmospheric pressure. However, for combined variation of temperature and pressure a new empirical expression has been added and validated for temperatures higher than 35°C. In a second part, the aeronautic environment effects on the partial discharge properties were investigated. The obtained noticeable changes in the PD characteristics with temperature, pressure and humidity variations were presented and mainly explained on the basis of electron mean free path. Finally, after having investigated the effect of temperature, pressure, and moisture on discharge characteristics, we focused on the effect of these environmental parameters on the behaviour of the energy dissipated by the discharges and on polyimide film endurance during aging under partial discharge. The energy measurements were carried out in real time during aging tests and the relationship between the energies involved and the polyimide lifetime was investigated for different environmental conditions. Accordingly to these results, it seems difficult to establish a direct relationship between the energy dissipated and the material lifetime, even if it still valid in various conditions. This is mainly due to the interaction between the discharge by-products and the environment that affects the film endurance. A more effective relationship between lifetime and the discharge intensity has been found. It has been shown that the lifetime and the discharge intensity are inversely proportional regardless of the applied conditions
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Sorensen, E. Todd. "Cross-linkable polyimide blends for stable membranes." Thesis, Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/10086.
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Sexton, Charles W. "Infrared spectroscopic study of polyimide film degradation." CardinalScholar 1.0, 2009. http://liblink.bsu.edu/uhtbin/catkey/1540709.
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This thesis focuses on the study of solvent degradation on polyimide films. Polyimides spun on silicon and freestanding polyimide films were exposed to solvents as a function of time at a constant temperature. The polyimide spun on silicon was immersed in dimethyl sulfoxide (DMSO) at 90oC for 30, 90, 270, and 450 min. Infrared spectra were obtained via multiple-bounce attenuated total reflection (ATR) and reflection-absorption (RA) spectroscopy. Thickness calculations were made using interference fringes obtained from RA spectra for each time interval. A reduction of thickness was observed with a total difference of 1.5 μm suggesting film degradation as a function of solvent exposure. Spectral changes in the symmetric and asymmetric carbonyl stretching modes were observed in both the ATR and RA sampling, which could be attributed to further curing of the polymer.
Two experiments were performed on the freestanding polyimide film. The first experiment exposed the film to DMSO and the second to n-methyl pyrollidinone (NMP).
In both instances, the freestanding film was immersed in the solvent at 98oC for 30, 90, 270, and 450 min. Infrared spectra were obtained via single-bounce ATR and transmission spectroscopy. No noticeable differences in spectra were observed. Thickness calculations were made using interference fringes obtained from transmission spectra. After immersion in DMSO, the thickness of the film increased initially, but then no significant changes in thickness occurred after 30 min. The initial increase in thickness may be due to solvent being trapped inside the film.
After immersion in NMP, the thickness calculations showed no change in film thickness. However, our data as well as past researchers suggested some increase in thickness must occur due to solvent absorption. We propose that film degradation may be occurring in the NMP at approximately the same rate as swelling, thus no net decrease in thickness could be observed. This hypothesis is supported by the fact that a yellow coloration was visually observed to be in the solvent after immersion of the freestanding film. A subtraction of a spectrum of fresh NMP solvent from the spectrum of the yellow–colored solvent showed bands consistent with polyamic acid, a starting material for the freestanding film, which could have been formed from a hydrolysis reaction.Literature review and introduction -- Evaluation of sampling techniques -- Film degradation studies on freestanding films.
Department of Chemistry
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Silva, Marta Sofia Fragoso da. "Polyimide and polyetherimide organic solvent nanofiltration membranes." Master's thesis, FCT - UNL, 2007. http://hdl.handle.net/10362/1133.
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Integrally asymmetric skinned Lenzing P84 and Matrimid 5218 polymide membranes and Ultem
1000 polyetherimide membranes were prepared. Crosslinking of membranes using aliphatic
diamines resulted in marked improvement in chemical stability. This however resulted in a
decline in flux with only Lenzing P84 demonstrating good flux in DMF. Further variation of
membrane dope parameters and operating conditions allowed for good control of the MWCO of
membranes made from Lenzing P84. SEM pictures of Lenzing P84 membranes revealed a
significant difference in membranes morphology. The presence of macrovoids increased when
using more DMF in the dope solution. These studies demonstrate the possibility of developing
OSN membranes using different polyimides and opens up future possibilities for controlling the
MWCO of these membranes. Preliminary modelling demonstrates that good control of the
MWCO could extend the application of OSN membranes to allow the fraction of molecules in
the NF range.
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Cerrón-Infantes, Alonso, and Miriam M. Unterlass. "High-Performance polyimide particles with angular shape." Revista de Química, 2016. http://repositorio.pucp.edu.pe/index/handle/123456789/99080.
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Los polímeros de alto rendimiento (HPP) desempeñan un rol importante en la actualidad. El desarrollo de métodos más económicos para sintetizar estos polímeros minimizando el impacto tanto en la salud como en el medio ambiente es una prioridad. Las poliimidas (PI) pertenecen al grupo de los HPP y presentan características excepcionales como una gran estabilidad ante elevadas temperaturas, alta resistencia a los productos químicos agresivos y a la radiación, así como propiedades de aislamiento. Sin embargo, la síntesis de las PI presenta aún retos importantes. En este artículo presentamos un enfoque alternativo para sintetizar PI de forma y tamaño impresionante.High-performance polymers (HPPs) play an important role in modern technology. Many efforts aim to develop cost-effective pathways to synthesize polymers without causing any harm to health and the environment. Polyimides (PIs) belong to the class of HPPs and they show outstanding features e.g. high-temperature stability, resistance to aggressive chemicals and radiation, as well as insulating properties. PI synthesis, however, present yet major challenges. We herein present an alternative approach to PIs of intriguing shape and of impressive size.
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Mecham, Sue Jewel. "Gas permeability of polyimide/polysiloxane block copolymers." Thesis, Virginia Tech, 1994. http://hdl.handle.net/10919/43136.
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A series of perfectly alternating polyimide/ poly(dimethylsiloxane) microphase separated block copolymers ranging from 0-50 wgt. % poly(dimethylsiloxane) have been measured for permeability characteristics. The polyimide segment of the copolymers was based on oxydiphthalicdianhydride (ODPA) and 1,4-Bis(4-amino-1,1- dimethylbenzyl)benzene (Bis P). The polysiloxane was an aminopropyl terminated poly(dimethylsiloxane). Randomly segmented block copolymers of =20 wet. % poly(dimethylsiloxane) with different segment lengths were also studied, based on the same materials for the sake of comparison with the perfectly alternating versions of the same block copolymers. Permeability measurements were performed on tough, microphase separated, transparent films with O₂, N₂, CH₄, and CO₂ gases in that order. The effects of the chemical composition and block lengths on permeability coefficients and selectivity values were evaluated. The permeability of copolymer films to gases was found to be highly sensitive to the morphology of the copolymer. The morphology was found to be controlled by varying the amount and the segment length of each component and this allowed for fine control of the permeability characteristics. Conversely, the measurement of permeability characteristics can lead to more information about the morphology of complicated microphase separated block copolymers.Master of Science
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Horning, Leslie Sauder. "Development of polyimide/metal gradient microcomposite films." Thesis, Virginia Tech, 1990. http://hdl.handle.net/10919/44460.
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Polyimides are attractive polymers because of valued intrinsic properties such as high thermal stability and good solvent resistance. At the same time, much effort is put into modifying polyimides to introduce different properties. This thesis describes a study where polyimides were modified with soluble metal compounds in an effort to create microcomposite films in which the location of the composite structure was controlled; namely at the film interfaces.
Two different modification techniques were used in this study, in-situ chemical generation and infusion deposition. Results indicate that infusion deposition was successful in producing a gradient microcomposite structure in polyimide films when silver(I)nitrate was the metal dopant. Analysis revealed that formation of the microcomposite structure depends upon the glass transition temperature and precure temperature of the polyimide film being modified.Master of Science
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Зленко, Віталій Олександрович, Виталий Александрович Зленко, Vitalii Oleksandrovych Zlenko, Сергій Іванович Проценко, Сергей Иванович Проценко, and Serhii Ivanovych Protsenko. "Dispersed Co thin films on polyimide substrate." Thesis, Видавництво СумДУ, 2011. http://essuir.sumdu.edu.ua/handle/123456789/20647.
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Nelson, Warren W. "Synthesis and Characterization of Polylactide/Polyimide Blends." University of Cincinnati / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1282575053.
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Surya, Ramakrishna. "Synthesis and Characterization of Polyimide/Polyacrylonitrile Blend." University of Cincinnati / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1574417741513506.
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Girardeaux, Christophe. "L'interface titane/polyimide. Etude experimentale et theorique." Paris 7, 1993. http://www.theses.fr/1993PA077259.
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L'objet de cette these est axe a la fois sur la caracterisation physico-chimique (xps, afm, raman) de l'interface obtenue par evaporation de titane sur du polyimide et sur la modelisation de cette interface par calculs scf afin de mieux comprendre les mecanismes d'interaction qui se produisent entre le metal et le polymere. Le premier chapitre resume les differentes theories de l'adhesion ainsi que les methodes experimentales generalement utilisees pour la quantifier. La seconde partie du travail est axee sur une synthese bibliographique des resultats deja publies sur differentes interfaces titane, chrome, cuivre aluminium-polyimide. Le troisieme chapitre, l'etude de l'interface titane/polyimide, met en evidence d'une part le fait que la rupture est cohesive et d'autre part la presence de particules d'oxyde de titane qui fragilisent l'adherence. La quatrieme partie montre l'effet d'un plasma oxygene sur la chimie et l'adhesion de cette interface. Enfin, dans le dernier chapitre est presentee une modelisation de l'interaction titane-polyimide permettant d'expliquer en partie le spectre xps experimental
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Mecham, Sue J. "Gas permeability of polyimide/polysiloxane block copolymers /." This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-06112009-063219/.
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Delozier, Donavon Mark. "Preparation and characterization of polyimide/organoclay nanocomposites." W&M ScholarWorks, 2002. https://scholarworks.wm.edu/etd/1539623403.
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The purpose of this research was to prepare nanocomposite materials comprised of exfoliated clay particles in a polyimide matrix. Poly(amide acid)/organoclay solutions and polyimide/organoclay films were prepared and the clay dispersion was characterized by visual inspection, XRD, and TEM. Mechanical measurements and certain thermal characterization measurements were also obtained. The research began by attempting to repeat the procedures set forth in the literature. Most of the polyimide/organoclay nanocomposites were being prepared by mixing prepared poly(amide acid) solutions with organoclay solutions. This simple mixing technology was used in the preparation of various polyimide/organoclay hybrid formulations. In-situ polymerization, which involved performing the polymer synthesis in the presence of the organoclay, replaced simple mixing with increased success. Although the in-situ polymerization technique was successful at exfoliating clay particles in certain polyimides, the organoclay degraded at the polyimide cure temperature. In order to raise the use temperature, the aliphatic surfactants found in commonly used organoclays were replaced with aromatic surfactants. The dispersion of the clay was more difficult with the aromatic surfactants. It was facilitated by reducing the charge on the clay surface. This was achieved by replacing some of the cations that reside on the surface of the clay particles with lithium ions in the interior of the particles. The in-situ polymerization of APB-BPDA poly(amide acid) in the presence of an aromatic organoclay with a cation exchange capacity (CEC) of 0.57 meq/g and subsequent cure to the polyimide yielded a film with a high level of clay dispersion.
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Robillard, Kerri Ann. "The Imidization Reactions of PMR-15 Polyimide." W&M ScholarWorks, 1992. https://scholarworks.wm.edu/etd/1539625735.
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Sim, Seok-Hoon. "Modifications of polyimides and polyimide-inorganic oxide hybrids with perfluoroether oligomers for use as matrices for carbon-fibre composites." Thesis, Loughborough University, 2004. https://dspace.lboro.ac.uk/2134/35624.
Full textAbstract:
The performance of a polyimide derived from a low molecular weight polyamic acid (Skybond 703) and the corresponding polyimide-silica hybrids, used as matrices for Carbon-fibre composites, was evaluated. The study involved the incorporation of telechelically modified perfluoroether oligomers into the resin systems. Telechelic modifications of the hydroxyl-terminated perfluoroether oligomer were carried out in order to achieve the required compatibility with the polyimide phase through grafting reactions with the polyamic acid precursor. In the case of hybrids, the compatibility requirements were extended also to the prehydrolysed alkoxysilane solution added to the polyamic acid mixtures. The latter was achieved with the incorporation of a silane coupling agent (γ-glycidyloxypropyltrimethoxysilane), which resulted in the formation of nano-scale silica domains in the polyimide.
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Holmes, Brenda L. "Effect of a derivatized oxide layer and environment on the bond durability of aluminum/polyimide and titanium/polyimide bonds." Thesis, Virginia Tech, 1994. http://hdl.handle.net/10919/41597.
Full textAbstract:
A surface pretreatment for aluminum and titanium
involving the reaction of phosphonic acid (RPO(OH)2),
R=butyl or vinyl for aluminum and R=vinyl for titanium, has
been investigated. The durability of phosphonic
acid-pretreated samples was compared with that for P2-etched
(ferric sulfate-sulfuric acid) adherends. Samples were
bonded with LaRC-IA adhesive in a wedge test geometry.
Environmental testing consisted of static and cyclical
exposure for 240 hours in three atmospheres: 1) 170°C, 2
torr; 2) -20°C; 3) 60°C, 70% relative humidity. Crack
propagation arrested within 48 hours. The order of
durability in static environmental tests for aluminum was
vinyl phosphonic acid > P2 > butyl phosphonic acid. The
durability performance was reversed for cyclic testing. The
durability of specimens using P2-etched titanium was
superior to that for vinyl phosphonic acid-treated titanium
in all environmental tests.
Master of Science
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Lopes, Mafalda Pessoa. "Influence of commercially available polyimide and formation conditions on the performance and structure of asymmetric polyimide organic solvent nanofiltration membranes." Master's thesis, Faculdade de Ciências e Tecnologia, 2009. http://hdl.handle.net/10362/5906.
Full textAbstract:
Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para a obtenção do grau de Mestre em Engenharia Química e BioquímicaThis work covers experimental and theoretical research related to the impact of the polymer structure of commercially available polyimide and polyetherimides as well as the formation conditions on the performance and structure of polyimide Organic Solvent Nanofiltration membranes. The influence in some membrane formation parameters such as polymer choice, solvent system composition, chemical crosslinking, solubility, humidity and coagulation bath temperature on the performance of PI membranes was investigated. A series of integrally skinned asymmetric membranes were prepared using different polyimide polymers, like Lenzing P84, P84 HT, Matrimid 5218 polyimide membranes and also polyetherimides membrane Ultem 1000. Non-crosslinked membranes were used to evaluate the influence of the polyimide choice and solvent system choice- DMF/1,4-Dioxane, NMP/THF and DMSO/Acetone in terms of performance and morphology. Non chemically modified membranes in DMF/1,4-Dioxane solvent system demonstrated low reproducibility. Polyimide P84 was found to generate tighter membranes with better rejection and higher flux performance than the other polyimides in study. Calculations were made to test the hypothesis that solubility parameters interaction can be a useful tool in theoretical predictions of PI OSN membranes performance and structure. Membrane formation conditions influenced membrane performance, but not to such extension as polymers and solvent system composition choice. SEM pictures revealed a significant difference in membranes morphology. The presence of macrovoids was higher in P84 and HT than in Matrimid and Ultem. These studies open up future possibilities for controlling the MWCO of different PI OSN membranes.
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Suzuki, Takeharu, and n/a. "Integrated, Intelligent Sensor Fabrication Strategies for Environmental Monitoring." Griffith University. School of Microelectronic Engineering, 2004. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20040813.131206.
Full textAbstract:
The humidity, temperature, wind speed/direction micro sensors can be manufactured individually, resulting in three individual substrates. The integration of the three sensors into a single substrate is a vital challenge to achieve an integrated intelligent sensor so called a multiple sensor. This requires the integration of process flows and is a major challenge because adequate sensor performance must be maintained. Polyimide was selected as a humidity sensing material for its compatibility with conventional integrated circuit fabrication technology, negligible temperature dependence and good resistance against contamination. Nickel was selected for the temperature and wind speed/direction sensor because of its useful temperature coefficient and the advantage of its cost. Since the known wet etchant for nickel requires hard-baked photoresist, a method which does not attack the polyimide while removing the photoresist must be developed. The method developed for etching nickel employs hard-bake-free photoresist. Other challenge was ensuring good thermal isolation for the wind speed/direction sensor fabricated on a silicon nitride layer preformed on top of a silicon wafer. Since silicon acts as a good heat sink, the silicon under the sensor was etched entirely away until the silicon nitride layer was reached. This structure achieved good thermal isolation resulting in small power consumption. This low power feature is essential for sensors deployed in fields where power access or replacement of power sources is restricted. This structure was compared with the structure created by polyimide plateau on a silicon nitride layer coated on a silicon substrate as a function of power consumption. Based on the examination of thermal isolation, the multiple sensor utilizing a MEMS technique was fabricated with a single-sided mask aligner. The characteristics of humidity sensors fabricated with polyimide were examined in detail with respect to variations of electrode structures, improvement of sensitivity, effect of process temperature, temperature and frequency dependence, and stability. The humidity sensor constructed with O2 plasma treated polyimide resulted an improvement in sensitivity and hysteresis. The investigation using XPS, FTIR and AFM concluded the chemical modification of polyimide played an important role in this improvement. The design, fabrication and results of a series of humidity sensors are quantified. There is always no unique packaging solution for sensors because of the application-specific nature of the sensors. This intelligent environmental monitoring system was designed to accommodate both an environmental sensor and its signal conditioning electronics circuitry (SICONEC) into a single package. The environmental sensors need direct exposure to the environment while SICONEC needs a sealed encapsulation to avoid environmental damage. A new style of packaging addressing these requirements was demonstrated using a hot embossing machine. The hot embossing machine was used to embed an integrated circuit (IC) in a bare die condition into a polycarbonate (PC) sheet. In this case, the IC was flipped down against the PC, which protects the front side of the IC from the environmental damages. In a test phase, a die containing operational amplifiers was embossed into the PC. A humidity sensor and surface mount resisters were placed on the same surface of the PC to test the validity of this new technique. Interconnection between the embossed die and the humidity sensor was established using bonding wires. Copper tracks were also used to ensure all electrical connections for the die, the humidity sensor and the resistors. The results clarified the method developed. Details of process methods, issues and further potential improvement are reported.
39
Suzuki, Takeharu. "Integrated, Intelligent Sensor Fabrication Strategies for Environmental Monitoring." Thesis, Griffith University, 2004. http://hdl.handle.net/10072/367295.
Full textAbstract:
The humidity, temperature, wind speed/direction micro sensors can be manufactured individually, resulting in three individual substrates. The integration of the three sensors into a single substrate is a vital challenge to achieve an integrated intelligent sensor so called a multiple sensor. This requires the integration of process flows and is a major challenge because adequate sensor performance must be maintained. Polyimide was selected as a humidity sensing material for its compatibility with conventional integrated circuit fabrication technology, negligible temperature dependence and good resistance against contamination. Nickel was selected for the temperature and wind speed/direction sensor because of its useful temperature coefficient and the advantage of its cost. Since the known wet etchant for nickel requires hard-baked photoresist, a method which does not attack the polyimide while removing the photoresist must be developed. The method developed for etching nickel employs hard-bake-free photoresist. Other challenge was ensuring good thermal isolation for the wind speed/direction sensor fabricated on a silicon nitride layer preformed on top of a silicon wafer. Since silicon acts as a good heat sink, the silicon under the sensor was etched entirely away until the silicon nitride layer was reached. This structure achieved good thermal isolation resulting in small power consumption. This low power feature is essential for sensors deployed in fields where power access or replacement of power sources is restricted. This structure was compared with the structure created by polyimide plateau on a silicon nitride layer coated on a silicon substrate as a function of power consumption. Based on the examination of thermal isolation, the multiple sensor utilizing a MEMS technique was fabricated with a single-sided mask aligner. The characteristics of humidity sensors fabricated with polyimide were examined in detail with respect to variations of electrode structures, improvement of sensitivity, effect of process temperature, temperature and frequency dependence, and stability. The humidity sensor constructed with O2 plasma treated polyimide resulted an improvement in sensitivity and hysteresis. The investigation using XPS, FTIR and AFMconcluded the chemical modification of polyimide played an important role in this improvement. The design, fabrication and results of a series of humidity sensors are quantified. There is always no unique packaging solution for sensors because of the application-specific nature of the sensors. This intelligent environmental monitoring system was designed to accommodate both an environmental sensor and its signal conditioning electronics circuitry (SICONEC) into a single package. The environmental sensors need direct exposure to the environment while SICONEC needs a sealed encapsulation to avoid environmental damage. A new style of packaging addressing these requirements was demonstrated using a hot embossing machine. The hot embossing machine was used to embed an integrated circuit (IC) in a bare die condition into a polycarbonate (PC) sheet. In this case, the IC was flipped down against the PC, which protects the front side of the IC from the environmental damages. In a test phase, a die containing operational amplifiers was embossed into the PC. A humidity sensor and surface mount resisters were placed on the same surface of the PC to test the validity of this new technique. Interconnection between the embossed die and the humidity sensor was established using bonding wires. Copper tracks were also used to ensure all electrical connections for the die, the humidity sensor and the resistors. The results clarified the method developed. Details of process methods, issues and further potential improvement are reported.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Microelectronic Engineering
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Saysouk, François. "Élaboration et caractérisation de films polyimide-nitrure de bore nanocomposites pour l'isolation électrique à haute température." Toulouse 3, 2014. http://thesesups.ups-tlse.fr/2445/.
Full textAbstract:
La recherche permanente de l'intégration et/ou du fonctionnement dans des régions chaudes des dispositifs électroniques de puissance se traduit par une augmentation du niveau des contraintes électriques et thermiques imposées à tous leurs constituants. Cela concerne en particulier les constituants des modules de puissance et des machines tournantes à haute température. Suite à une étude bibliographique qui a permis d'analyser les différentes structures d'isolations pouvant être adaptées à un fonctionnement à haute température (>200°C), il ressort en particulier un besoin en couches diélectriques minces afin d'isoler les différentes parties des module de puissance et des machines tournantes. Les polyimides, matériaux polymères thermostables, bien qu'ils soient de bons candidats pour ce type d'applications présentent cependant des limites d'un point de vue électrique lorsqu'ils sont utilisés dans cette gamme de températures élevées. L'introduction de nanoparticules inorganiques dans la matrice polyimide, peut être une solution pour renforcer les propriétés diélectriques. La disponibilité de nouvelles nanoparticules permet d'envisager des performances accrues des matériaux jusqu'à 400 °C sous fort champ. Durant cette thèse, de nouveaux nanocomposites polyimide/nitrure de bore (PI/BN) ont été élaborés et leurs propriétés diélectriques ont été étudiées particulièrement dans la gamme 200 °C à 350 °C. En particulier, l'étude de l'influence de la taille des nanoparticules de BN (entre 40 nm et 250 nm) a été étudiée. De nombreuses améliorations ont été apportées au niveau du procédé d'élaboration des nanocomposites PI/BN, notamment pour lutter contre la formation d'agglomérats dans la matrice limitant les performances des propriétés diélectriques sous fort champ électrique. Les améliorations de ces dernières comparées au PI non chargé se traduisent au niveau des pertes diélectriques, des courants de conductions et de la conductivité électrique par une diminution de l'ordre de 2 à 4 décades dans la gamme de températures considérées. De plus, le champ de claquage comparé au polyimide non chargé a été multiplié par deux à 350°C dans le cas d'un des nanocomposites élaborés. Finalement une analyse des différents mécanismes physiques de conduction électrique impliqués dans cette amélioration a été réaliséeThe advanced research for warm regions integration and/or operation in power electronics, results in an increased level of electrical and thermal stresses imposed on all their constituents. This concerns, in particular, the components of the power modules and high temperature rotating machines. In literature a thin dielectric layer for the high temperature (> 200 °C) isolation of different parts in power modules and rotating machines is missing. Polyimides, thermosetting polymer materials, are good candidates for this type of applications; however in this range of temperatures, these are limited from an electrical point of view. The introduction of inorganic nanoparticles in the polyimide matrix can be a solution to enhance its dielectric properties. The availability of new nanoparticles allows the fabrication of increased performance nanocomposites with high electric field and high temperature (up to 400 °C) performances. In this thesis, novel polyimide/boron nitride (PI/BN) nanocomposites have been prepared. Their dielectric properties were studied particularly in the range from 200 °C to 350 °C. Also, the influence of the size of the nanoparticles of BN (between 40 nm and 250 nm) has been studied. It's known that the presence of agglomerates in the nanocomposites limits the dielectric properties under high electric field; many improvements have been made in this direction to ameliorate the fabrication process. Dielectric losses, conduction currents and electrical conductivity improvements have been obtained in the nanocomposites compared to the neat matrix: a 2 to 4 decades reduction has been measured in the considered temperature range. Furthermore, the breakdown field resulted doubled at 350 °C for nanocomposites. Finally an analysis of the various physical mechanisms involved in the electrical conduction improvement was realised
41
Dunson, Debra Lynn. "Synthesis and Characterization of Thermosetting Polyimide Oligomers for Microelectronics Packaging." Diss., Virginia Tech, 2000. http://hdl.handle.net/10919/27394.
Full textAbstract:
A series of reactive phenylethynyl endcapped imide oligomers has been prepared in either fully cyclized or amic acid precursor form. Soluble oligomers have been synthesized with controlled molecular weights ranging from 2- to 12 Kg/mol. Molecular weight characterization was performed using SEC (size exclusion chromatography) and 13C-NMR, revealing good agreement between the theoretical and experimental (Mn) values. Crosslinked polyimides were obtained by solution or melt processing the oligomers into films and gradually heating in a programmed temperature manner up to the appropriate reaction temperature for the phenylethynyl groups, which is approximately 350-400°C. Thermal analysis of the resulting films showed high glass transition temperatures (>300°C) and excellent thermal stability, comparable to those found for thermoplastic control polyimides. The crosslinked films also had exceptional solvent resistance as evidenced by a high gel fraction (greater than or equal to 95%) following extraction in common solvents for several days. This was in contrast to the amorphous thermoplastic controls, which quickly dissolved upon immersion in solvents.
The monomers used for synthesizing the polyimide oligomers were varied systematically within the series to study the influence of both molecular structure and molecular weight on the physical and film-forming properties. The incorporation of fluorinated monomers, such as 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA), reduced water absorption and lowered the dielectric constant relative to non-fluorinated polyimides in the series. When flexible ether linkages were incorporated in the repeat unit by using 4,4'-oxydianiline (ODA), relatively more ductile solvent-cast films were obtained from oligomers having Mn values as low as 10 Kg/mol. Additionally, oligomer Mn and the relative rigidity/symmetry of the repeat unit structure greatly influenced the solubility of polyimides in NMP. For example, even 6FDA/p-phenylenediamine based oligomers with Mn values targeted below 10 Kg/mol precipitated from NMP at 180°C during solution imidization.
The relationship between solution viscosities of polyimide and poly(amic acid) thermosetting oligomers and wetting/spreading ability to form continuous films during spin casting was elucidated. Employing o-dimethoxybenzene (DMB) as a cosolvent with NMP improved the film-forming ability of the fully imidized 6FDA/ODA oligomer series. This was evidenced by a decrease in viscosity (via suppression of physical-type gel formation) and better overall coverage and clarity of the films. Humidity was found to have a detrimental effect, causing the polyimide oligomers to phase separate to form cloudy or porous films. When moisture was reduced, oligomers having Mn greater than or equal to 6 Kg/mol formed spin cast films of <20 micrometer thickness with good qualitative adhesion to several inorganic substrates.
Dielectric constants (epsilon) were estimated for several of the polyimides by measuring the refractive indices (n) of the films and using Maxwell's relationship (epsilon at optical frequencies is equal to n raised to the second power). The apparent dielectric constants were low, ranging from 2.47 to 2.75.
The novel combination of low dielectric constant, solvent resistance and isotropic physical properties inherent in the thermosetting polyimide oligomers makes these materials excellent candidates for use as thin film insulating layers in microelectronics packaging applications.Ph. D.
42
Schlea, Michelle Renee. "Processing and characterization of high performance polyimide nanocomposites." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/39557.
Full textAbstract:
The goal of this work was to achieve a homogeneous morphology of carbon nanotubes in a polyimide matrix, characterize the resulting nanocomposite properties, and understand structure-property relationships. Melt-mixing was used as an effective method for dispersing multiwall nanotubes and carbon nanofibers in a phenylethynyl terminated imide resin where aggregation occurred only in particle-saturated systems. Particle network formation within the nanocomposites was studied using rheology and impedance spectroscopy; results showed that the electrical percolation threshold occurred at a lower particle loading than the rheological percolation threshold, consistent with the oligomer size in comparison to the distance for electrical conductivity (~5 nm). Thermomechanical analysis showed that the addition of nanoparticles enhanced the polyimide storage modulus and thermal behavior indicated that the nanoparticles restricted polymer motion to higher temperatures. A study of the cure mechanism of the oligomer with and without nanoparticles showed that the nanoparticles reduced the activation energy required for cure initiation while increasing the obtainable extent of cure at various isothermal temperatures. The work presented in this dissertation shows that an easy, time effective processing method can be used to homogeneously disperse nanoparticles in an imide oligomer, and the resulting nanocomposites exhibit enhanced properties. A business plan is also presented that reflects the market potential of this technology.
43
Sturgill, G. Kip. "Stabilization of polyimide blends through solid-state crosslinking." Diss., Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/10080.
Full text
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Chuang, Yen-Ling, and 莊燕鈴. "Preparation and Properties of Polyimide/Clay and Polyimide/Titania Nanocomposite Materials." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/90298028628155407390.
Full textAbstract:
碩士中原大學
化學研究所
91
Abstract This essay is divided into two parts。 In the first part，a series of polyimide/clay nancomposite materials consist of electroctive polyimide and clay were successfully prepared。 Aniline trimer，4,4-oxydianiline (ODA) and 4,4-oxydiphthalic anhydride (OPDA) were employed to synthesize polyimide。 The polyimide/clay nancomposite materials were prepared by effectively dispersing the inorganic nanolayers of MMT clay in to the organic Polyimide matrix via an chemical imidization up to 300℃polymerization。 The as-synthesized polyimide/clay nanocomposite materials were characterized by FTIR、XRD and TEM。 The incorporation of MMT clay in polyimide matrix show better thermal properties、gas barrier properties and ionic conductivity。 The second part is the preparation and properties of organic/inorganic compound of polyimide/TiO2 nanocomposite materials。 TiO2 was introducedd to polyimide matrix by a chelating ligand which was different from traditional sol-gel process。 In this study，we also found the thermal and mechanic properties would will rise by increasing the content of inorganic oxide TiO2 through TGA，DMA and tensile test。 The permeability properties of H2O，O2 and N2 were obviously reduced as TiO2 content increased。
45
Lin, Hung-Ju, and 林弘儒. "The study of polyimide-silica hybrid derived from the 4,4-hexafluoroisopropylidene dianiline based polyimides." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/644ra5.
Full textAbstract:
碩士中原大學
化學工程研究所
93
In this study, a series of 4,4-hexafluoroisopropylidene dianiline based polyimides were prepared using three different kinds of dianhydride. In addition, in order to promote the glass transfer temperature of polyimide, we will use the TEOS for Sol-Gel reaction to make the organic/inorganic hybrid materials. Our results are shown that 6FDA-6FDAm of these fluorinated polyimides have the lowest dielectric constant, it will be low for 2.7, this result is shown that more fluorinated groups will reduce dielectric constant substantially, besides our results are also shown that silica hybrid polyimide will promote the glass transfer temperature substantially, it will rise to 352℃（@ 30 wt% silica hybrid）from 328℃,but the dielectric constant still hold in 3.1, this result is shown that added silica particles will rise the glass transfer temperature of 6FDA-6FDAm. Finally, all of 4,4-hexafluoroisopropylidene dianiline based polyimides show good thermal stability (>480℃), good mechanical properties (Young modulus>1.2 GPa), and good diffusion barrier to resist copper penetration, this result is shown that these materials have good opportunity to be used as low-k materials in microelectronic process.
46
Chen, Yuan-Bao, and 陳源保. "Metallization of Polyimide Film." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/34059526572317612293.
Full textAbstract:
碩士國立高雄應用科技大學
化學工程與材料工程系
97
The film characterization of surface silvered polyimide film (PI-Ag film) based on self-synthesized PI film (s-BPDA/4,4’-ODA type) and commer-cial PI film (Du Pont® PI film, D-PI film, PMDA/ODA type) were suffi-ciently discussed. PI-Ag films were prepared by the base treatment, ion-exchange reaction and different reduction methods. There are four re-duction methods, including a method at elevated oven temperature at 300 oC (Method I), a method at 300 oC oven and nitrogen gas purged (Method II), in oven under the vacuum at 200 oC (Method III), and in reduction agent N,N-dimethylformamide (DMF) solution (Method IV). The PI-Ag films were characterized by X-ray diffraction (XRD), Energy dispersive X-ray spectroscopy (EDX), Scanning electron microscopy (SEM), four probe points, UV-Visible and cross-cut tester. A better surface properties for each PI film (self-synthesized, and com-mercialized) has been achieved by the reduction Method I. The reflectivity of these samples was higher than 75% and 70% respectively for PI film and D-PI film. Surface resistivity was 0.2 Ω/sq and 0.3 Ω/sq respectively for PI film and D-PI film. The silver layer thickness was 400 nm and 500 nm re-spectively for PI film and D-PI film. Cross-cut tester showed a good adhe-sion between PI film (or D-PI film) and silver layer on PI-Ag film.
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Chang, Jen-Cheng, and 張鎮城. "Study on modified polyimide." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/13933866263968453654.
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Lai, Young-Woei, and 賴永偉. "Solvent Effect on the Imidization Kinetics During Reactive Blending of Polyimide / Polyimide Molecular Composites." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/82603501582660003128.
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Yuan, Yu-Cheng, and 袁宇呈. "Thermal Conductivity of Inorganic Fillers and Liquid Crystal Polyimide Blending with Commercial Polyimide Composites." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/76715271413056805064.
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TSAI, Tung-Ying, and 蔡東穎. "the study of soluble polyimide." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/18513217788266274675.
Full textAbstract:
碩士國立成功大學
化學工程學系
86
Abstract The synthesis of soluble polyimide was carried out by 1,4-bis(4- aminophenoxy)-2-tert-butylbenzene (BATB) which containing pendent bulky tert-butyl substituent with 3,3'',4,4''-tetracarboxylic dianhydride (BTDA) via a solution imidization procedure in an organic solvant . The structures of soluble polyimides have been identified by the analysis of infrared spectra , 1H-NMR spectra and pattern of x-ray diffraction . Furthermore , TGA , DSC , TMA , and DMA measurements are used to evaluate the thermal stability , glass transition temperature , thermal expansion coefficient and thermal mechanical properties .The mechanical properties such as tensile strength of various polyimide films were also obtained by using universal testing instrument . The molecular weight of polymers were decreased sharply initial stage during solution imidization under high temperature , and then , the molecular weight increases with increasing reaction time . Finally , reached a maximum of steady state . A highly imidization rate (almost 100% imidization) of soluble polyimide may be obtained at 180℃ for 16 hours . The copper foil clad polyimide films was prepared by coating soluble polyimide and polyimide precursor (PAA) solution on the copper foil respectively , and then heated from 50℃ to 300℃ . From the observation of SEM , it can''t observed that any copper particles was diffused into the polyimide layer , the result will cause no change the characteristics of polyimide . In the contrast to the case of polyamic acid coating , it is observed that much more copper particles are migrated in polyimide film near the interface of copper foil , the result will cause most properties of polyimide to be reduced .