Electron transfer as the initiation mechanism of photocurable maleimide-vinyl ether based resins

Maleimide-vinyl ether resins polymerise upon UV irradiation without the add ition of a photoinitiator. The first step of initiation is an electron tran sfer from a ground state vinyl ether molecule to the triplet maleimide. Abs olute rate constants for the reaction of triplet maleimide (lambda(max) = 2 60 and 320 nm) with maleimide itself, unsaturated monomers, inorganic ions, and alcohols were determined by laser flash photolysis. The mechanisms (el ectron and hydrogen transfer, depending on the substrate) are identified by FT-EPR. (C) 1999 Elsevier Science Ltd. All rights reserved.