Sulfur-containing polyurethanes as novel macro photoinitiators comprising in-chainbenzophenone and coinitiator amine for photopolymerisation

摘要

Problems with low molecular weight photoinitiators, such as odour, yellowing and migration, have prompted the development of macrophotoinitiators or polymeric photoinitiators, based on type I or II photoinitiator systems. The type II initiators, the most commonly used being benzophenone, require a hydrogen donor, tertiary amines typically used. However, tertiary amines suffer odour, toxicity, migration and mutagenicity issues, such that they may be worse than the low molecular weight photoinitiators. One approach is to have the initiator and co-initiator in the same macromolecule.