新型改性咪唑潜伏固化剂的制备及应用

Preparation and application of a new modified imidazole latent curing agent

以N-乙烯基咪唑、丙烯酸甲酯、丙烯酸乙酯为原料,N,N-二甲基甲酰胺(DMF)为溶剂使用可逆加成-断裂链转移技术(RAFT),通过自由基共聚制备了咪唑类潜伏型环氧树脂固化剂(VME)。对VME的分子结构进行了红外表征。将制备的VME与环氧树脂E51混合固化,研究了固化物(VME/E-51)的热分解性能及力学性能。结果表明:Flynn-Wall-Ozawa法、Kissinger法和Starink法求得的VME/E-51热分解表观活化能E较为相近。以Coast-Redfern法获得了VME/E-51的热分解动力学方程,并据该方程推测固化物的热分解过程为JMA过程。与N-乙烯基咪唑固化的E-51体系相比,VME/E-51体系具有优异的耐热性及力学性能。

The imidazole-based latent epoxy resin curing agent(VME)was prepared by free radical copolymerization using N-vinylimidazole,methyl acrylate and ethyl acrylate as raw materials and N,N-dimethylformamide(DMF)as solvent,with the help of reversible addition-fragmentation chain transfer technology(RAFT).The molecular structure of VME was characterized by FT-IR.The prepared VME and epoxy resin E51 were mixed and cured,and the thermal decomposition and mechanical properties of the cured product(VME/E-51)were studied.The results showed that the apparent activation energy E of thermal decomposition of VME/E-51 obtained by Flynn-Walling Ozawa method,Kissinger method and Starink method were relatively similar.The thermal decomposition kinetic equation of VME/E-51 was obtained by the Coast-Redfern method,and the thermal decomposition process of the cured product was speculated to be the JMA process based on the equation.Compared with the E-51 system cured by N-vinylimidazole,the VME/E-51 system has excellent heat resistance and mechanical properties.