Organosilicon Liquid Crystal Polymers and Elastomers Prepared by Metal-Free Photocatalytic Hydrosilylation Polymerization

Abstract

In the synthesis of organosilicon liquid crystal polymers (LCPs) and elastomers (LCEs), platinum-catalyzed hydrosilylation stands as the predominant synthetic method. However, this approach often relies on noble platinum catalysts that are difficult to remove. In this study, we synthesize a series of organosilicon LCPs and LCEs via photocatalytic, metal-free hydrosilylation polymerization of silanes and diene-terminated mesogenic monomers, using an organic photocatalyst alongside a hydrogen atom transfer catalyst. The resulting LCPs and LCEs have well-defined backbone structures, excellent thermal and mechanical properties. Notably, the monodomain LCEs exhibit impressive thermal-driven actuation capabilities due to their main-chain organosilicon structures and low LC-to-isotropic phase transition temperatures. This advance is expected to provide new opportunities for the applications of organosilicon LCP and LCE materials in biomedical research and material science.