不同分子量的陶瓷前驱体聚硅氮烷的结构与性能的研究

Research of chemical structures and properties of pre-ceramic polymer polysilazanes with different molecular weights

以甲基氢二氯硅烷、甲基乙烯基二氯硅烷为原料,采用氨解反应以及热聚合反应合成了-系列乙烯基氢基甲基聚硅氮烷（PSZ135-170）,其数均分子量（Mn）在2.9×10^3-1.9×10^5之间,单位浓度聚合物的粘度（ηred）在0.06-0.49mL/g之间.通过FTIR 和1H NMR对聚硅氮烷结构进行了表征,该系列聚硅氮烷具有无定型结构,可溶解于正己烷、甲苯、乙酸乙酯、二氯甲烷和N,NG二甲基甲酰胺等常用有机溶剂中,通过TGA 分析了该系列聚硅氮烷的热性能,发现随着聚硅氮烷分子量的增加,在N2中25-700℃热解后剩余物的百分含量逐渐升高,最高可达72.58%.

A series of Vinylhydromethylpolysilazanes(PSZ135-170)were prepared from dichlorohydromethylsilane and dichloromethylvinylsilane by ammonolysis polycondensation and thermopolymerization.The vinylhydromethyl polysilazanes have number-average molecular weights(Mn)of 2.9×103-1.9×105.The reduced viscosity(ηred)of the polymers are 0.06-0.49mL/g.The structures of the polysilazanes were characterized by FT-IR and 1 H NMR.The polysilazanes are amorphous and soluble in common organic solvents such as hexane,toluene,ethyl acetate,dichloromethane,N,N-dimethylformamide and so on.The thermal properties of the polysilazanes were analyzed by TGA.It was found that the residual percent of the series of the PSZ enhanced gradually after pyrolysis in nitrogen at 25-700 ℃ along with the increasing of molecular weights,could almost reach 72.58%.