Ester-Activated Vinyl Ethers as Chain Transfer Agents in Radical Photopolymerization of Methacrylates

The regulation of multifunctional methacrylates to yield tough photopolymers is a widely researched topic, whereby addition-fragmentation chain transfer (AFCT) agents represent one viable class of additives. Vinyl ethers have been described as potent AFCT agents in radical polymerization but are unexamined in network formation via photopolymerization. In this article, we present a sterically hindered vinyl ether as AFCT agent for methacrylate networks, which shows enhanced acid stability opposed to vinyl ethers described in the literature. After synthesis and confirmation of the efficient regulation in a monofunctional system, the reactivity and mechanical properties in a difunctional methacrylate were evaluated. An increase in double bond conversion, significantly lower shrinkage stress, and high toughness were assessed and substantiated the great potential of this compound in photopolymerizable resins.