Search for Dual-Initiator Synergy in UV-Initiated Acrylate-Epoxy Hybrid Polymerization Systems

摘要

Photo-polymerization has many advantages over traditional thermal polymerization. including lower energy requirements, high levels of temporal and spatial control, and higher polymerization rates. In hybrid photopolymerizations of acrylate-epoxy monomer mixtures more advantages are realized in that hybrid resins are less sensitive to oxygen and moisture than the respective neat systems. The main drawback to hybrid systems is the disparity in the reactivity of the two monomer types used: typically acrylates are much more reactive than the epoxides, which often leads to suppressed epoxide conversion. The development of systems that produce high levels of conversions in both species is desirable. One method to increase the conversion and rate of polymerization of the epoxide moeities is introducing radical species that can be oxidized to the respective carbon-centered cation. This approach is called radical-promoted cationic polymerization and is shown in Figure 1. The focus of this research was to observe the result of additional radical initiator on the epoxide conversion in UV-initiated hybrid polymerizations.