Sulfur-containing polyurethanes as novel macro photoinitiators comprising in-chain benzophenone and coinitiator amine for photopolymerization

摘要

Three novel sulfur-containing polyurethanes (PUs) as macrophotoinitiators, hydroxyl-terminated PUa and PUb, and amino-terminated PUc, were synthesized through polycondensation of a novel diamine 4,4’-bis[(4- amino)thiophenyl]benzophenone (BATPBP), isophorone diisocyanate (IPDI) and N-methyldiethanolamine (MDEA). The beznophenone and coinitiator amine structures were successfully introduced into the backbones of PUs. FT-IR, 1H NMR, GPC and DSC analyses confirmed their structures and properties. UV-vis spectra indicate that the macromolecular structure nearly has no influence on their UV-vis absorptions. A trifunctional monomer of trimethylolpropane triacrylate (TMPTA), initiated by these macrophotoinitiators with a low-molecular-weight photoinitiator system (benzophenone/MDEA) as the reference, was studied through photo differential scanning calorimetry (photo-DSC). The results show PUa is the most efficient photoinitiator and the molar content of coinitiator amine in PUs has an important effect on their photoefficiency.