超支化聚碳硅氮烷的合成与表征

聚碳硅氮烷是一种新型含硅有机金属聚合物,其主链由硅氮碳连接而成,侧链为有机基团;与其它含硅聚合物(聚硅氮烷、聚碳硅烷等)类似,聚碳硅氮烷适于用做力学性能极佳且耐高温氧化的氮化硅(Si3N4)和氮化硅/碳化硅(Si3N4/SiC)复相陶瓷的前驱体.[1]超支化聚合物具有溶解性好、粘度低

SYNTHESIS AND CHARACTERIZATION OF HYPERBRANCHED POLYCARBOSILAZANE

In order to enhance the reactivity of the silyl-containing ceramic precursor,a hyperbranched silyl-containing polymer with low viscosity and plenty of terminal vinyl-groups was prepared.A novel AB_4 type monomer,bis(N,N-diallylamino)methylsilane,was synthesized first by aminolysis of MeHSiCl_2 and then was polymerized via hydrosilylation reaction using H_2PtCl_6 as the catalyst.The polymerization process was monitored by FT-IR spectroscopy.The polymer product was purified via precipitation using ethyl ether and acetonitrile and was analysed by using()~1H-NMR、()~(29)Si-NMR and FT-IR spectroscopy.The results indicated that the polymer was hyperbranched polycarbosilazane,and α-hydrosilylation was the main reaction.The degree of branching(DB) of the hyperbranched polymer was 0.56 calculated from the()~(29)Si-NMR spectrum,and the average molecular weight(M_w)was 13 580 g/mol determined by light scattering method.It was found that there still existed a lot of functional vinyl end groups,which can be used as promising reaction centers for curing or modification of the polycarbosilazane.