液体型咪唑衍生物对环氧树脂固化行为的影响

Effects of Liquid Imidazole Derivatives on Curing Behaviors of Epoxy Resin

研究了2-乙基-4-甲基咪唑(2E4MI),1-苄基-2-甲基咪唑(1B2MI)和1-(3-氨基丙基)咪唑(API)三种液体型咪唑衍生物对环氧树脂(EP)固化反应行为和固化物性能的影响。采用非等温差示扫描量热(DSC)法研究了三种体系不同升温速率下反应的放热行为及固化度变化,运用Friedman法研究了各体系在不同固化度下的活化能,通过等温DSC法比较了120℃下的固化行为,对固化物的玻璃化转变温度(T_(g))及力学性能进行了研究。结果表明,2E4MI,1B2MI和API均可单独用作固化剂来固化EP,而且与EP的相容性极好。此外,三种体系的反应机理完全不同,EP/2E4MI反应分三步进行,而EP/1B2MI和EP/API反应分两步进行。活化能(E_(a))结果表明,EP/2E4MI在反应前期的E_(a)最低,后期最高,EP/1B2MI与其正好相反,EP/API居中。反应速率大小顺序为EP/API>EP/2E4MI>EP/1B2MI。EP/1B2MI的T_(g)为102.29℃,表现出最佳热性能。

The effects of three liquid imidazole derivatives including 2-ethyl-4-methylimidazole(2E4MI),1-benzyl-2-methylimidazole(1B2MI)and 1-(3-aminopropyl)imidazole(API)on the curing reaction behaviors of the epoxy resin(EP)and the performance of the cured EP were studied.The non-isothermal differential scanning calorimetry(DSC)method was used to study the exothermic behaviors and curing degree of the reaction of the three systems at different heating rates.The activation energy of each system at different curing degrees was studied by Friedman method.The curing behaviors at 120℃was compared by isothermal DSC method,and the glass transition temperature(T_(g))and mechanical properties of the cured EP were also studied.The results show that 2E4MI,1B2MI and API can be used alone as curing agent to cure EP,and have excellent compatibility with EP.In addition,the reaction mechanisms of the three systems are completely different.The EP/2E4MI reaction proceeds in three steps,while the EP/1B2MI and EP/API reactions proceed in two steps.Activation energy(E_(a))results show that the E_(a)of EP/2E4MI is the lowest in the early stage of the reaction and the highest in the late stage,while that of EP/1B2MI is the opposite,and that of the EP/API is in the middle.The order of reaction rate is EP/API>EP/2E4MI>EP/1B2MI.The T_(g)of EP/1B2MI is 102.29℃,showing the best thermal performance.