桐油三酸环氧固化剂的制备及其固化反应动力学

Study on the preparation and curing reaction kinetics of tung oil ternary acid epoxy curing agent

采用桐酸甲酯为原料,经DA加成、水解反应后制得桐油三酸（TOTA）,FTIR和1H-NMR分析结果表明目标产物合成成功。使用非等温DSC示差扫描法对桐油三酸环氧体系和桐马酸酐环氧体系的固化反应动力学进行了研究。通过Crane的n级反应法确定了固化体系的反应机理函数,并通过外推法优化了固化工艺参数。结果表明,2种体系的线性拟合系数均达到了0.998,n级反应模型在5~20 K/min的升温速率下与实验值误差较小,适合表征该体系的固化反应过程,2种固化体系的优化固化工艺条件分别为120℃/2 h＋140℃/2 h和100℃/2 h＋120℃/2 h,即桐油三酸环氧体系的固化温度要稍高于桐马酸酐环氧固化体系;然而力学性能分析测试表明桐油三酸环氧固化体系的刚性和拉伸力学强度显著强于桐马酸酐环氧固化体系。

The tung oil ternary acid （TOTA） was synthesized by DA addition reaction and hydrolyzation using tong oil acid methyl ester as raw material. The FFIR and ^1H-NMR analysis results showed that target product was successfully synthesized. The curing reaction kinetics of TOTA-epoxy curing system and tong oil acid polymerized maleic anhydride （TMA）-epoxy curing system were all studied by using the non-isothermal differential scanning （DSC） analysis method. The reaction mechanism function of curing system was also studied with the n-order reaction method of Crane, and the curing reaction parameters were optimized by extrapolation method. The results showed that the linear fitting coefficients of two curing systems could reached 0.998, n-order reaction models were close to the experimental data at the heating rate of 5-20 K/min, which were suitable to characterize the curing reaction procedure. The optimized curing process conditions of these two curing systems were 120 ℃/2 h ＋ 140 ℃/2 h and 100 ℃/2 h ＋ 120 ℃/2 h, respectively, which indicated that the TOTA-epoxy curing system had a higher curing temperature than TMA-epoxy curing system. However, mechanical performance analysis showed that the rigidity and tensile strength of TOTA-epoxy curing system was much higher than those of TMA-epoxy curing system.