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以不同比例的甲基氢二氯硅烷(0,20％,50％,80％和100％(摩尔分数))和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一系列不同组成的乙烯基氢基甲基聚硅氮烷(PVHMS),其重均分子量在8．61×104~4．0×105之间.通过FT-IR 和1 H NMR 对该系列聚硅氮烷的结构进行了表征,发现它们属于无定型结构；0％(摩尔分数) PVHMS 为线型结构,呈粘流态,可溶解于常用有机溶剂中,在 N2中1000℃热解后剩余物百分含量为61．80％；20％(摩尔分数)PVHMS 具有交联的支化结构,加热变硬,不溶于常用有机溶剂,热解后剩余物百分含量为57．41％；50％(摩尔分数)PVHMS 为含有少量环状结构的线型聚合物,加热到91℃变软,可溶解于常用有机溶剂中,热解后剩余物百分含量为71．00％；80％(摩尔分数)PVHMS 为含有少量环状结构的线型聚合物,加热到140℃左右变软,可溶解于常用有机溶剂中,热解后剩余物百分含量为80．81％；100％(摩尔分数)PVHMS 具有流苏型支化结构,可溶于热的极性有机溶剂中,加热至300℃无明显的热塑性和热固性变化,热解后剩余物百分含量为85．30％.作为陶瓷前驱体该系列聚硅氮烷既具有易加工的性能,在陶瓷化过程中又具有较高的陶瓷化收率.

A series of vinylhydromethylpolysilazanes were prepared from different proportion of dichloromethyl-silane (0%,20%,50%,80%,100mol%)and dichloromethylvinylsilane by ammonolysis and thermopolymeriza-tion.The polysilazanes have weight-average molecular weights (M w )of 8.61 ×10 4-4.0 ×10 5 .The structures of the polysilazanes were characterized by FT-IR and 1 H NMR.The polysilazanes are amorphous.0mol% PVHMS has linear structure,shows viscous flow,and was soluble in common organic solvents,its remain percentage was 61.8% after pyrolysis at 1 000 ℃ in N2 ;20mol% PVHMS has branched structure,and it became harden when heated,it was not soluble in common organic solvents,its remain percentage was 57.41% after pyrolysis;50mol% PVHMS was a linear polymer,containing small amount of rings,its soften temperature was 91 ℃ and soluble in common organic solvents,its remain percentage was 71.00% by pyrolysis;80mol% PVHMS was a linear polymer containing a more rings,its soften temperature was about 140 ℃ and has solubility in common organic solvents,its residual percentage was 80.81% after pyrolysis;100mol%PVHMS has tassels structure,no obvious change was observed when it was heated,and it was soluble in common organic polar solvents,its resid-ual percentage was 85.30% after pyrolysis.As the pre-ceramic polymer,the series of polysilazanes possess easy processing performance and higher yield of ceramics during polymer-to-ceramic transform.