乙烯基聚硅氮烷PSN-1热裂解研究

摘要

The characteristics of pyrolytic process of vinyl-containing polysilazane in the temperature range of 0～1000℃ was investigated by TG,IR,and XRD.It was found that the pyrolytic process consisted of three stages.In the first stage (0～260℃) weight loss was about 48%,mainly from volatilization of small molecules ; in the second stage the weight loss was small,the C=C bond began to crosslink and completed by 500℃,the total weight loss was 58% by 700℃; and in the last stage the transformation from organic materials to mineral was accomplished.More α-Si3N4 crystalloids were obtained by increasing the temperature of pyrolytic and extending time of pyrolytic temperature.%通过TG、IR、XRD等实验手段,研究分析了含乙烯基聚硅氮烷(PSN-1)在0～1000℃范围内热裂解过程的特性.实验表明,PSN-1的热裂解过程可分为三个阶段:第一阶段为0～260℃,该阶段质量损失率较大(48%),主要以小分子挥发为主;第二阶段为260～700℃,该阶段PSN-1中的C=C双键开始发生交联,至500℃已基本交联完全,质量损失率相对较小,至700℃质量损失率为58%;第三阶段700～1000℃.基本上已没有有机基团,完成无机化转变过程.裂解温度及保温时间对Si3N4晶体生成都有影响,提高裂解温度和延长保温时间可以进一步获得数量较多的α-Si3N4晶体.