可光固化超支化聚硅氧基硅烷的合成与表征

自20世纪80年代末期Kim和Webster首次采用AB2型单体合成超支化聚合物以来，超支化聚合物以其新颖的结构、独特的性能和广泛的应用前景受到了科学界和工业界的广泛关注．其中超支化有机硅聚合物，尤其是硅氧基聚合物，由于具有良好的高低温稳定性、耐腐蚀性、耐候性等，以及硅氯、硅氢等末端基团易于功能化改性的特点，使其在功能性涂层材料、催化剂以及液晶材料等领域具有重要的应用价值．到目前为止，有关超支化聚硅氧基硅烷的研究主要集中在AB2型单体（x≥2，A和B分别为硅氢基团和乙烯基、烯丙基等不饱和基团）的制备以及硅氢加成产物的功能化改性方面．

SYNTHESIS AND CHARACTERIZATION OF UV CURABLE HYPERBRANCHED POLY(SILOXYSILANE)

A new monomer,vinyltriallylsilane(CB_3),having functionnal groups with different hydrosilylation reactivity was designed and synthesized by allylation reaction from vinyltrichlorosilane.Then,photocrosslinkable hyperbranched(poly(siloxysilane)) with terminal allyl groups was prepared via hydrosilylation reaction of vinyltriallylsilane(CB_3) and dimethylbis(dimethylsiloxy)silane(A_2) monomers at the presence of Karstedt catalyst,and characterized by means of FTIR,()~1H-NMR,()~(29)Si-NMR,and SEC/RI/MALLS technology.The polymerization process of A_2 and CB_3 monomers was studied in situ by using FTIR.It was found that silicon hydride would preferentially react with vinyl groups during the reaction. This can cause to the generation of an intermediate with one Si—H and three allyl groups.By using it to conduct further self-polymerization,hyperbranched polymer can be obtained.The degree of branching of the resulting hyperbranched poly(siloxysilane) was calculated to be 0.44 by quantitative()~(29)Si-NMR spectroscopy,and the weight average molecular weight was 12.1 kg/mol with its polydispersity of 2.52.Finally,the UV curing behavior of the resulting polymer initiated with different photoinitors was also investigated.