【摘要】 本文采用TGA、IGA、GC和 GC-MS比较了主链含环二硅氮烷硅橡胶与一般硅橡胶的热稳定性,发现硅氮橡胶在升温失重时,起始失重温度比甲基硅橡胶高150—200℃,在350℃氮气下恒温热失重要比甲基和苯基硅橡胶低十多倍。环二硅氮烷的存在是硅氮橡胶主链热稳定性好的原因。另外硅氮橡胶主链中的硅氧链节数目,对其热稳定性几乎无影响,硅氮橡胶主链热降解机理与甲基硅橡胶不同,它的降解是先经过链之间的重排。更多还原

【Abstract】 The thermal stabilites of silicone gums containing cyclodisilazane,(SCD), E=Me, Ph, Were studied in comparison with methyl and phenyl silicone gum by the method of TGA. IGA. GC. and GC-MS. The initial temperature of the weight loss of SCD is 150-200℃ higher than that of methyl silicone gum, the wedght loss is 10-20 times less than that of methyl as well as phenyl silicone polymer. Based on both the GTA and the IGA data, the presence of cyclodislazane in SCD enhances the resistance of the main chain to degradation and the weight loss remains almost the same as the number (x) of Me2SiO groups in SCD changes. Outstanding stability of this material makes them to be used potentilly as high-temperatuse elastomers. Acceding to analysis of the decomposed products a two steps mechanisum of degradation is proposed.更多还原