Thiol-Ene Photopolymerization of Well-Defined Hybrid Graft Polymers from a Ladder-Like Polysilsesquioxane

Abstract

A ladder-like structured poly(mercaptopropyl) silsesquioxane (LPMPSQ) was synthesized in one-bath, under mildly basic conditions at room temperature. Obtained LPMPSQ was utilized as a macroinitiator for thiol-ene graft photopolymerization of various vinyl monomers to give hard, soft, hydrophobic, and hydrophilic graft copolymers with low PDI (<1.4). Synthesized hybrid graft copolymers were characterized by H-1 NMR, Si-29 NMR, FTIR, GPC, TGA, and DSC. Thermal studies with these hybrid graft copolymers revealed that the ladder-structure substantially increased the thermal stabilities in the form of increased glass transition temperatures and higher degradation temperatures over their organic analogues.