咪唑衍生物作为环氧树脂潜伏性固化促进剂的研究

Research on imidazole derivatives as latent curing accelerator for epoxy resin

利用2-甲基咪唑(2MI)和2-乙基-4-甲基咪唑(EMI)分别与氯化偏苯三酸酐(TAAC)发生亲核取代反应,制备得到了2-甲基咪唑-氯化偏苯三酸酐(2MI-T)和2-乙基-4-甲基咪唑-氯化偏苯三酸酐(EMI-T),并将其用作环氧树脂/酚醛树脂(E/P)体系的潜伏性固化促进剂。通过核磁共振氢谱(1H-NMR)和傅里叶红外谱图(FT-IR)证明了2MI-T和EMI-T的成功合成。利用示差扫描量热法(DSC)研究了E/P体系的非等温固化行为,结果表明加入改性咪唑的体系固化放热峰整体向高温区移动约40℃。固化动力学分析表明体系的活化能平均升高约15 kJ/mol,证明改性后的咪唑具有良好的热潜伏性。此外红外光谱及DSC分析表明单组分E/P体系的贮存期可达四周。

The 2-methylimidazole-trimellitic anhydride chloride(2MI-T)and 2-ethyl-4-methylimidazole-trimellitic anhydride chloride(EMI-T)were synthesized by nucleophilic substitution reaction of trimellitic anhydride chloride(TAAC)with 2-methylimidazole(2MI)and 2-ethyl-4-methylimidazole(EMI),respectively.The imidazole derivatives were used as latent curing accelerators for epoxy/phenolic resin(E/P)systems.The successful synthesis of 2MI-T and EMI-T was demonstrated by1H-NMR and FT-IR.The nonisothermal curing behavior of the E/P systems was investigated by DSC.The results showed that the curing exothermic peaks of the systems with modified imidazole moved to the high temperature region as a whole by about 40℃.The analysis of curing kinetics showed that the activation energy of the system was increased by about 15 kJ/mol on average,which proved that the modified imidazole had good thermal latency.In addition,infrared spectroscopy and DSC analysis showed that the shelf life of the single-component E/P system could be up to four weeks.