Role of Organic Phosphates and Phosphonates in Catalyzing Dynamic Exchange Reactions in Thiol?Click Vitrimers

Owing to their strong Brønsted acidity, organic phosphates and phosphonates are able catalyze dynamic transesterification reactions in hydroxyl ester networks. Compared commonly used catalysts, they highly soluble a wide range of acrylate monomers neither affect cure kinetics nor shelf-life photocurable thiol-acrylate resins. Additionally, promote fast stress relaxation and, by using derivatives with functional groups, covalently incorporated within the photopolymer network. These salient features make ideal catalysts for design processing photoreactive vitrimers. Herein, catalytic activity selected methacrylate-functional vinyl-functional on transesterifications studied comprehensively. They providing –OH moieties. Cure thermomechanical properties not significantly affected structure functionality catalyst. In contrast, time-dependent measurements show that time activation energy correlate well logarithmic acid dissociation constants acids. The better understanding role expands scope is particularly interesting vitrimers, which can be additively manufactured vat polymerization techniques.