聚四甲基对硅亚苯基-二苯基硅氧烷共聚物的制备及其耐热性能

Thermal property and preparation of poly(tetramethyl-p-silylphenylene-diphenyl siloxane) via Si-H/Si-OR polycondensation process

以1,4-双(二甲基硅基)苯(BDSB)和二苯基二甲氧基硅烷为原料,B(C6F5)3为催化剂,通过Si-H/Si-OR缩聚的方法制备了聚四甲基对硅亚苯基-二苯基硅氧烷共聚物(PTMPS-DPS)。研究了催化剂用量、反应温度对缩聚反应的影响,并用29Si NMR对产物的微观结构进行表征,用TG、DSC对产物的热性质进行了表征。制备PTMPS-DPS适宜的反应条件是:B(C6F5)3浓度6.3mmol/kg,反应温度60℃。微量水分能增加产物的嵌段性。产物接近于交替结构,嵌段数为96,Tg=-5.2℃,在N2、空气中的5%热失重温度分别是357℃、360℃,700℃时的残留分别为32%、37%。

Poly（tetramethyl-p-silylphenylene-diphenyl siloxane） （PTMPS-DPS）was synthesized by dehydrocarbon process using 1,4-bis （dimethylsilyl）benzene and diphenyldimethoxylsilane as start materials and B（C6 F5 ）3 as catalyst. The relationship between B（C6F5 ）3 concentration, reaction temperature and polycondensation rate was investigated. ^29Si NMR was used to characterize the structure of the polymer, TG and DSC was used to characterize its thermal property. PTMPS- DPS was preferably synthesized at 60℃ catalyzed by 6.3nmlol/kg of B（C6 F5 ）3. The existence of trace H2O increaseed the randomization of the prepared polymer. ^29 Si NMR showed that the polymer was approximately alternate with a run number value of 96. The Tg of the polymer was -5.2℃ ,and the polymer began to degrade at 357℃ in nitrogen with a residue of 32% and 360℃ in air with a residue of 37% at 700℃.