Abstract
1,3-Bis(4-(p-aminophenoxy)phenyl-1,1,3,3-tetramethyldisiloxane (BAPPSi) and 2,2-bis(4- (p-aminophenoxy)phenylpropane (BAPPA) were synthesized by terminal nitrophenyl etherification of 1,3-bis(p-hydroxyphenyl)disiloxane (HPDS) and bisphenol-A, respectively, followed by reduction using hydrogen with Pd-C catalyst. Two types of polyimide were prepared via polyamic acids by using corresponding diamines, BAPPSi and BAPPA, with some aromatic acid dianhydrides. The curing temperature for imidation was determined as 200 °C for 1 hour by FT-IR spectra of temperature conversion in the reaction. This condition was for 1 hour. Properties such as heat resistance (5% weight loss temperature), water contact angle, and adhesion toward glass were compared between these polyimides. Water repellency and adhesion of polyimide-siloxanes after 50 hr at 120 °C and 95%RH were superior to those of usual polyimides without siloxanes, although heat resistance of both polyimides was almost same extent (< 500 °C). The blend-polyimides prepared by mixing corresponding polyamic acids derived from BAPPSi and BAPPA showed higher adhesive ability than copolyimides from copolyamic acids using both diamines. It was found that even small amount of siloxane in the blend-polyimides contribute to enhancing the adhesion toward glass.
