Model copolymerization reactions. Evidence against concerted complex addition in reactions of simple alkyl radicals with N-phenylmaleimide and donor olefins

Abstract

Reductive demercuration was used to generate the 1-butyl and benzyl radicals in mixtures of N-phenylmaleimide (NPM) and either of the donor olefins styrene or 2-chloroethyl vinyl ether (CEVE). In each case, the major products of the reaction were derived from simple addition of the radical to NPM followed by transfer of a hydrogen atom to the initial adduct. Careful mass balances on NPM showed that mechanisms other than simple addition did not constitute important pathways for monomer consumption. These results argue against mechanistic schemes for radical copolymerization in which 1:l monomer complexes add in a concerted manner to growing macroradicals.

Light-induced crosslinking polymerization of a novel N-substituted bis-maleimide monomer

“…The photoinduced polymerization of electron donor/-electron acceptor monomer systems has been extensively studied in the past few years, mainly the vinyl ether/maleimide combination, as such non-acrylate UV-curable resins have the distinct advantage of undergoing a rapid polymerization upon UV exposure in the absence of any added photoinitiator [1][2][3][4][5][6][7][8][9]. Some N-substituted maleimide monomers have been shown to undergo homopolymerization even when they are exposed neat to UV-radiation, provided that the monomer contains easily abstractable hydrogens [8].…”

Functional Polymers with Controlled Microstructure Based on Styrene and N ‐Substituted Maleimides

“…This phenomenon was observed even though the Alfred-Price Q and e values remained similar to those of other styrene-N-substituted maleimide systems in which copolymers with a higher degree of alternation were obtained [30]. Other N-substituted maleimides copolymerized with styrene included N-n-hexyl maleimide [31], N-cyclohexyl maleimide [31], N-benzyl maleimide [31], N-phenyl maleimide [32][33][34][35], N-(alkyl-substituted phenyl) maleimides [33], N-(substituted phenyl) maleimides [36], N-(1-naphtyl) maleimide [37], N-(2-chlorophenyl) maleimide [38], N-pentafluorophenyl maleimide [39], N- [3,5-bis(trifluoromethyl)phenyl] maleimide [39], N-(3-trifluoromethylphenyl) maleimide [39], N-(4-trifluoromethylphenyl) maleimide [39], and N-maleoyl amino acids prepared from maleic anhydride and an amino acid, either L-alanine or L-phenylalanine [40]. Alternating copolymers prepared from styrene and N-substituted maleimides bearing an initiator allowing the introduction of grafts from the copolymer backbone by atom-transfer radical polymerization (ATRP) have been described first by Ç akir et al using (2,5-dioxo-2,5-dihydro-1h-pyrrole-1-yl)methyl 2-bromopropanoate as the N-substituted maleimide followed by polymerization of methyl methacrylate by ATRP to create the grafts [41].…”

Preparation of high‐selective HPLC packing materials based on alternating copolymer‐grafted silica

“…poly(ODA-alt-OMI)-grafted silica. The alternating copolymer can be obtained by copolymerization of an electronrich (donor-type) monomer and an electron-deficient (acceptor-type) monomer through formation of chargetransfer complexes [34,35]. The selectivity results for the three alternating copolymer-grafted silica packing materials will also be compared and discussed in the following sections.…”