A Mechanoredox Catalyst Facilitates ATRP of Vinylcyclopropanes

Abstract

Radical ring-opening polymerization (rROP) of vinylcyclopropanes (VCPs) represents an important class of polymerization reactions. Despite the versatility of atom transfer radical polymerization (ATRP) in accessing well-defined polymers, the rROP of VCPs by Cu-catalyzed ATRP remains a formidable challenge. In this study, we propose an efficient mechanically controlled ATRP (mechano-ATRP) approach for different VCPs. This process utilized a mesoporous ZnO (m-ZnO), which effectively prevents Cu catalyst poisoning and promotes the rROP process. The coordination environment of VCP with Cu and a polymer on the m-ZnO surface was confirmed by experimental observations and calculations. The mechano-ATRP yielded poly(VCPs) with a predictable molecular weight, low dispersity, and high chain-end fidelity. This method was employed in the vinylcyclopropane-based resin curing process. The incorporation of m-ZnO can enhance the mechanical properties and reduce the volume shrinkage of the resin. Furthermore, the application of the m-ZnO film as an external catalyst enabled the production of a transparent resin.