含苯基聚碳硅烷的合成与结构分析

Synthesis and structure characterization of phenyl-containing polycarbosilane.

在聚二甲基硅烷中添加质量分数为1.5%的二乙烯基苯,通过共热聚反应制备了含苯基的聚碳硅烷。用IR、UV、1H NMR、13C NMR及29Si NMR对产物的结构进行了表征,并在此基础上讨论了聚合反应机理。粗产物产率可以达到50%;粗产物经过减压蒸馏后,软化点约为200℃,重均摩尔质量约为3 000 g/mol,分散系数约为7.6,陶瓷产率可达75%。熔融纺丝实验证明,产物具有较好的可纺性,可作为优良的SiC陶瓷纤维先驱体。

The phenyl-containing polycarbosilane(PPCS) was prepared by thermal polymerization of dimethlysilane and 1.5% mass fraction of divinylbenzen.The structure of PPCS was studied by IR,UV,()~1H-NMR,()^(13)C-NMR and()^(29)Si-NMR testing,and the mechanism of polymerization was discussed.The yield of raw resultant could reach 50%,and after decompression and distillation,its softening point was about 200 ℃,molar fraction was 3000 g/mol,dispersion coefficient was 7.6,the yield of ceramics could be 75%.The melting spinning experiment showed that PPCS could be used as an excellent SiC ceramic fiber precursor with good spinnability.