Announcement for Downloading full text filePlease respect the Copyright Act.
All digital full text dissertation and theses from this website are authorized the copyright owners. These copyrighted full-text dissertation and theses can be only used for academic, research and non-commercial purposes. Users of this website can search, read, and print for personal usage. In respect of the Copyright Act of the Republic of China, please do not reproduce, distribute, change, or edit the content of these dissertations and theses without any permission. Please do not create any work based upon a pre-existing work by reproduction, Adaptation, Distribution or other means.
URN etd-0817106-132335 Statistics This thesis had been viewed 2937 times. Download 1104 times. Author Sheng-Yu Huang Author's Email Address No Public. Department Chemical Engineering Year 2005 Semester 2 Degree Master Type of Document Master's Thesis Language English Page Count 79 Title SYNTHESIS AND PROPERTIES OF LOW COLOR POLY(ETHER IMIDE)S AND PI/SiO2 HYBRID FILMS Keyword low color hybrid material organic-inorganic material poly(ether imide) poly(ether imide) organic-inorganic material hybrid material low color Abstract ABSTRACT
In part I, a series of novel organosoluble and light-colored fluorinated poly(ether imide)s (IV) having inherent viscosities of 0.43-0.59 dL/g were prepared from 4,4’-[1,4-phenylenbis(isopropylidene-1,4-phenyleneoxy)]diphthalic anhydride (I) and various trifluoromethyl-substituted aromatic bis(ether amine)s by a standard two-step process with thermal and chemical imidization of poly(amic acid) precursors. These poly(ether imide)s showed excellent solubility in many organic solvents and could be solution-cast into transparent, flexible, and tough films. These films were essentially colorless, with an UV-visible absorption edge of 361-375 nm and a very low b* value (a yellowness index) of 15.3 to 17.0. They series also showed good thermal stability with glass-transition temperature of 191-248oC, 10% weight loss temperature in excess of 494oC, and char yields at 800oC in nitrogen more than 39%. The thermally cured poly(ether imide) films showed good mechanical properties with tensile strengths of 83-96 MPa, elongations at break of 8-11%, initial moduli of 1.7-2.0 GPa. They possessed lower dielectric constants of 3.25-3.72 (1MHz). In comparison with the V series nonfluorinated poly(ether imide)s, the IV series showed better solubility, lower color intensity and lower dielectric constants.
In part II, hybrid organic-inorganic materials based on polyimide-silica system have been produced by the sol-gel route from solution mixture of hydrolysed tetramethoxysilane (TMOS) and an aromatic poly(amic acid) prepared from 4,4’-oxydiphthalic dianhydride (ODPA) and 4,4’-bis(4-aminophenoxy)biphenyl (I”) with or without the use of 3-aminopropyltrimethoxysilane (APrTMOS) as a chain-end capper. The APrTMOS-modified hybrid films (V series) containing up to 40 wt% silica were mechanically robust and optically transparent. The V series hybrid films showed a higher optical transparency than the VI series analogs (without APrTMOS as the coupling agent). All the hybrid films showed excellent thermal stability, including moderately high Tgs of 243-254℃, 10% weight loss temperatures higher than 560 oC, and high char yields at 800oC in nitrogen (＞60%).
In part III, an alkoxysilane terminated amide acid prepolymer was prepared from 4,4’-bis(4-aminophenoxy)biphenyl (I”) or 4,4’-bis(4-amino-2-trifluoromethylphenoxy)- biphenyl (I’) with 4,4’-oxydiphthalic dianhydride (ODPA) using 3-aminopropyltrimethoxysilane (APrTMOS) as an end capper. Two series of polyimide/silica (PI/SiO2) hybrid films with chemical bonding between the polyimide backbone and silica network have been prepared from the mixture of APrTMOS-terminated prepolymer, tetramethoxysilane (TMOS), and water via a sol-gel reaction, followed by solution casting and multistep heating. The hybrid films containing up to 40 wt% silica were mechanically robust, transparent, and light-colored. The fluorine-containing PI/SiO2 hybrid films (IX series) showed a higher optical transparency and less color intensity than the non-fluorinated (VIII series). All the hybrid films showed excellent thermal stability, including moduately high Tgs of 242-266 ℃, 10% weight loss temperatures higher then 535 ℃, and high char yield at 800 ℃ in nitrogen (＞ 54%).
Advisor Committee Sheng-Huei Hsiao - advisor
Guey-Sheng Liou - co-chair
Wen-Fu Lee - co-chair
Files Date of Defense 2006-07-07 Date of Submission 2006-08-17