Silyl glyoxylates as high-performance photoinitiators for cationic and hybrid polymerizations: Towards better polymer mechanical properties

Silyl glyoxylates are proposed here as high-performance photoinitiators (PIs) for the hybrid polymerization of cationic and radical monomers. Recently, silyl glyoxylates were reported as a new class of high-performance Type I photoinitiators for free radical polymerization under air upon exposure to different near-UV and blue LEDs. In this article, we report this new class of photoinitiators to initiate cationic polymerization in combination with an iodonium salt. This system can also be used to initiate simultaneously free radical and cationic polymerizations, for example, for the free radical/cationic hybrid polymerization and for the synthesis of interpenetrating polymer networks. The system silyl glyoxylate/iodonium exhibits excellent polymerization performances and exceptional bleaching properties compared to other well established photoinitiators (e.g., camphorquinone). Furthermore, a hybrid monomer is also introduced in this article (2-vinyloxyethoxyethyl methacrylate [VEEM]) leading to a huge improvement of the mechanical properties of the final polymer through hybrid polymerization. (c) 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1420-1429