单分子体系光敏引发剂

Unimolecular Photoinitators For Free Radical Polymerization

本文介绍了各种单分子体系光敏引发剂的结构和引发机理以及它们的引发效率,特别从光反应的过程讨论了它们的NorrishⅠ型光解方式的α^-断裂和β^-断裂,同时也介绍了NorrishⅡ型的α^-断裂,并从自由基的三线态寿命总结了自由基活性对引发效率的影响.

An attempt has been made to riview the field of unimolecular photoinitiators for free radical polymerization, with particular emphasis on recent progress as far as machomistic work and photochemical efficiency are concerned, Many aromatic carbonyl compounds carrying particular functional groups undergo photofragmentatuis These reaction roughly fall into two type, which are α-cleavage and β-cleavage of Norrish type- Ⅰ or α-cleavage of Norrish type-Ⅱ, α-cleavage is proposed to proceed through a short--lived triplet excited state which govern free radical activa tion ,there is no universal photoinitiator system that is the best proposition for whatever application.