纳米SiO_2锚固光敏基团引发MMA光接枝聚合研究

THE ANCHORING OF THE PHOTOINITIATOR AND THE PHOTO-GRAFTING POLYMERIZATION OF MMA ON THE SURFACE OF NANOMETER SILICA PARTICLES

对纳米SiO2进行了锚固光引发剂的表面修饰,进而引发甲基丙烯酸甲脂(MMA)光接枝聚合制备有机/无机复合粒子.纳米SiO2粒子首先用氯化亚砜进行表面氯化,再与光引发剂2-羟基-4-(2-羟基乙氧基)-2-甲基苯丙酮(Irgacure2959)反应从而锚固上光引发剂.通过紫外光引发MMA在经过修饰过的纳米SiO2表面上进行表面光接枝聚合.采用IR、TGA和TEM等方法表征了接枝前后纳米粒子的变化,证明了表面接枝物的存在,并研究了不同反应条件对单体转化率、接枝率和接枝效率的影响.研究结果表明,搅拌对接枝过程的影响比较显著.TGA结果显示未搅拌聚合时接枝率只能达到比较小的程度,而在搅拌条件下180min内MMA的接枝率可达到110%.

The anchoring of the photoinitiator and the photo-grafting polymerization of methyl methacrylate （MMA） on the surface of nanometer silica particles have been performed. The anchoring of the initiator on the silica was achieved by treating silica with thionyl chloride and reacting with Irgacure2959. Poly（methyl methacrylate） （PMMA） has effectively grafting on the surface of the nanometer silica particles during the photo-grafting polymerization initiated by Irgacure2959. The change of particle surface and the grafting of PMMA polymers were confirmed by IR, TGA and TEM technique. Monomer conversion, grafting ratio and grafting efficiency under various conditions were investigated. It is shown that grafting reaction with stirring has a prominent effect on the grafting ratio and the grafting efficiency during the photo-grafting polymerization. The grafting ratio of MMA could be up to 110% initiated by Silica-2959 with stirring in the presence of nitrogen, and the thermostability of the products measured by TGA would be remarkably improved. However the grafting ratio can only reach a less degree in a static state （no stirring） during the process.