Synthesis of maleimide modified imidazole derivatives and their application in one-component epoxy resin systems

摘要

A series of novel maleimide modified imidazole derivatives were successfully synthesized through the addition reaction between N-(4-hydroxyphenyl) maleimide (HPM) and imidazole compounds with 1-position N-H bond. The maleimide modified imidazole derivatives were blended with epoxy resin (EP) to evaluate their reactivity and thermal latency. Compared with the common EP/imidazoles systems, the curing exothermic interval of the EP systems containing maleimide modified imidazole derivatives shifted to higher temperature regions. Moreover, the EP systems containing maleimide modified imidazole derivatives had much longer pot life under room temperature. The enhanced latency of maleimide modified imidazole derivatives was attributed to the strong electron withdrawing effect of maleimide group, which reduced the nucleophilicity of imidazole moiety. Notably, the maleimide modified imidazole derivatives regained fast curing ability towards EP by overcoming the curing reaction energy barrier under heating condition. (C) 2018 Elsevier B.V. All rights reserved.