【摘要】 以钠缩合法合成的含Si–Cl键的超支化聚硅烷(Cl-HPS)为基础,将其分别与4-羟基二苯甲酮和2-羟基硫杂蒽酮反应,制备了小分子光引发剂取代的超支化聚硅烷BP-HPS和TX-HPS.小分子光引发剂取代的超支化聚硅烷可以不同程度地扩展超支化聚硅烷的紫外吸收.采用实时红外光谱研究了它们引发己二醇二丙烯酸酯(HDDA)紫外光聚合行为.结果表明,小分子光引发剂取代的超支化聚硅烷的自由基引发效率高于未经取代的超支化聚硅烷和它们对应的小分子光引发剂的引发效率.电子自旋共振光谱研究表明,BP-HPS和TX-HPS既可以裂解产生硅自由基,也可以通过硅甲基参与的夺氢反应产生碳中心自由基.更多还原

【Abstract】 Two hyperbranched polysilanes, BP-HPS and TX-HPS, have been synthesized by the esterification of Cl-HPS, a Si–Cl containing hyperbranched intermediator which has been prepared by the Wurtz reaction of phenyltrichlorosilane and methylphenyldichlorosilane with sodium, with（4-hydroxyphenyl）（phenyl）methanone（BP-OH） and 2-hydroxy-9H-thioxanthen-9-one（TX-OH）, respectively. The photopolymerization behaviors of hexane-1,6-diyl diacrylate（HDDA） initiated by BP-HPS and TX-HPS under UV irradiation have been investigated by Real-time IR. Results show that the introduction of BP and TX into hyperbranched polysilanes not noly broadens their UV absorption, but also brings about higher efficiency in comparison to the hyperbranched polysilane and BP or TX. Electron spin resonance（ESR） analysis demonstrates that BP-HPS and TX-HPS not only produce silyl radical by the decomposition of Si–Si bonds, but also generate carbon radical by an efficient hydrogen abstract procedure from Si–CH₃.更多还原