光敏聚合中含二苯酮基高聚物的引发作用

PHOTOINITIATION OF POLYMERIC BENZOPHENONES IN THE PHOTOSENSITIZED POLYMERIZATION

合成了多种不同分子量和不同二苯酮侧基含量的高分子敏化剂PVB,从紫外吸收光谱及发射光谱的测定结果表明,PVB基本保持小分子二苯酮(BP)的光化学特性。采用PVB与叔胺组成光敏引发体系引发MMA光聚合时,聚合速度(R_ο)与小分子相比增加二倍以上。而且R_p随PVB分子中二苯酮基含量的增加而增加,当PVB分子量提高时引发聚合能力加强,这和高分子敏化剂分子链中高效率的能量传递以及色基的密集分布特性有关。

Some Polymeric benzophenones (PVB), having different molecular weight (MW) and various content of benzophenone as pendant group, have been synthesized and determined with absorption and emission spectra. The results obtained indicate that the BP group bound to PVB remains the photochemical properties characteristic of the small molecular BP. Using the Photoinitiation system composed of PVB and tertiary amine to induce photopolymeriza-tion of MMA, the polymerization rate (Rp) is above 2 times higher than that of small molecular BP. The polymerization rates increas with increasing content of BP pendant group and the photoinitiation efficiency increases with increasing molecular weight of PVB. These results can be attributed to the high-efficient energy transfer in polymer and the high local concentration of reactive chromophore in reaction system.