莫来石纤维前驱体溶胶-凝胶化转变的研究

以水为分散介质,硝酸铝、异丙醇铝、正硅酸乙酯为原料,聚乙烯吡咯烷酮为纺丝助剂,采用溶胶-凝胶法合成了莫来石纤维前驱溶胶,通过对流变、粘度以及折光指数的测试,研究了不同条件下莫来石纤维溶胶的凝胶化过程。根据Chambon-Winter(CW)法则确定了不同体系的凝胶化时间,探讨了溶胶-凝胶化转变过程中体系粘度的变化以及温度、添加剂对体系凝胶化时间的影响,为连续莫来石纤维干法纺丝工艺提供了一定的理论依据。

Study on the sol-gel transition of the precursor sol of mullite fiber

Using water as disperse medium,aluminum nitrate(AN),aluminum isopropoxide(AIP)and te- traethoxysilane(TEOS)as raw materials,polyvinylpyrrolidone(PVP)as a modifier,the precursor sol of mullite fiber was synthesized by sol-gel method.The sol-gel transition of mullite fiber precursor sol was investigated through rheological, viscosity and refractive indices measurements.The gelation time of the given system was determined according to Cham- bon-Winter(CW)criterion.The influences of PVP and aging temperature on the gelation time of the precursor sol were also observed.They exert great effects on the gelation time of the given system.From these work,it may provide scientif- ic basis for the preparation of the continuous mullite fiber.