论文部分内容阅读
用二甲基环体硅氧烷(DMC)在阴离子催化条件下开环反应制备了端羟基聚二甲基硅氧烷(HPDMS),将HPDMS与正硅酸已酯(TEOS)在二丁基二月桂酸锡(DBTDL)催化作用下交联合成了有机硅弹性体。研究了不同开环条件对HPDMS黏度的影响以及不同相对分子质量HPDMS的硫化,结果表明,DMC开环聚合发生的最低温度为80℃,阴离子本体聚合HPDMS的适宜工艺条件是:反应温度为120℃,反应时间为80 min,催化剂用量为DMC质量的0.03%。不同黏均相对分子质量的HPDMS硫化性能有较大差异,较低相对分子质量的HPDMS硫化成膜时间较短,且成膜后更柔软,表面更光滑,均匀性更高。但是低相对分子质量的聚合物成膜后较易被拉断。
Hydroxyl terminated polydimethylsiloxane (HPDMS) was prepared by ring-opening reaction of dimethylcyclone (DMC) under anion catalysis. HPDMS was reacted with tetraethoxysilane (TEOS) Silicone elastomers were crosslinked by DBTDL catalysis. The effects of different ring-opening conditions on the viscosity of HPDMS and the curing of different relative molecular mass HPDMS were studied. The results showed that the lowest temperature of ring-opening polymerization of DMC was 80 ℃. The suitable conditions of HPDMS for anionic bulk polymerization were as follows: the reaction temperature was 120 ℃ , The reaction time was 80 min, and the amount of catalyst was 0.03% of DMC. HPDMS vulcanizates with different viscosities and relative molecular weights are quite different. HPDMS vulcanizates with shorter molecular weight have shorter film forming time, softer film surfaces, smoother surface and higher uniformity. However, the low molecular weight polymers are more easily pulled off after film formation.