| Summary: | 碩士 === 國立成功大學 === 材料科學及工程學系 === 102 === Four kinds of low CTE polybenzoxazole precursors, polyhydroxyamides (PHAs), were synthesized by low temperature polymerization of 3,3'-dihydroxybenzidine (DHB), 2,2'-Bis(1,3-amino-4-hydroxyphenyl)hexafluoropropane (BisAPAF) and terephthaloyl chloride (TC) in NMP. These polymers were characterized by FT-IR, 1H-NMR, XRD, TMA, TGA, UV-Visible and universal testing machine. The inherent viscosities of these precursors were in the range of 0.42–0.89 dL/g. All of these polymers could be solution-cast into flexible and tough films. The cut off wavelength of polyhydroxyamides were in the range of 348–426 nm. After curing, these polybenzoxazoles (PBOs) showed CTE and Tg in the range of 18–41 ppm/℃ and 341–372℃, respectively. The polybenzoxazoles also showed good thermal stability, with 5% weight loss temperature being recorded above 500°C in air or nitrogen atmosphere. The strength of polybenzoxazoles was above 60MPa. The water uptake of these polybenzoxazoles was all below 1%. All polyhydroxyamides and polybenzoxazoles were amorphous.
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