高性能桐油基酸酐类环氧固化剂研究

Study on high-performance tung oil-based anhydride epoxy curing agent

针对目前桐油基酸酐环氧固化体系柔韧性与强度不能兼具的问题,以桐油为原料,通过酯交换、酯化、双烯加成等反应合成出含有2个羧基和1个酸酐的桐丁马酸酐(TBMA)。采用红外光谱、核磁氢谱、非等温DSC分析、力学性能及热稳定性测试等研究了TBMA固化环氧体系的反应动力学及性能并与桐油酸酐以及桐马酸酐环氧固化体系作了对比。结果表明,TBMA固化体系的反应活化能为72.82 kJ/mol,指前因子A为3.25×10^(8)s^(-1),固化反应级数为0.91,最优固化条件为120℃/2 h+140℃/2 h+160℃/2 h。固化体系的拉伸强度为49.61 MPa,断裂伸长率为14.86%,弹性模量为2 364.48 MPa,拉伸剪切强度为16.78 MPa,具有高强度、高模量、高柔韧性特点,并且其综合性能优于目前现有的桐油酸酐、桐马酸酐以及桐油聚酰亚胺酸酐固化体系。

Aiming at the problem that the current tung oil-based acid anhydride epoxy curing system could not have both flexibility and strength,a tung butyric maleic anhydride(TBMA) containing two carboxyl groups and one anhydride group was synthesized using tung oil as a raw material, through transesterification, esterification, diene addition and other reactions. The reaction kinetics and propertoes of TBMA cured epoxy system were investigated by Infrared spectroscopy, hydrogen nuclear magnetic spectrum, non-isothermal DSC analysis,mechanical properties and thermal stability tests and compared with those of tung oil anhydride and tung maric anhydride cured epoxy systems.. The results showed that the reaction activation,energy index factor A and curing reaction order of the curing system of TBMA was 72.82 kJ/mol,3.25×10^(8)s^(-1),and 0.91,respectively. The optimal curing condition was 120 ℃/2 h + 140 ℃/2 h + 160 ℃/2 h. The tensile strength,elongation at break,elastic modulus and tensile shear strength of of the cured system was 49.61 MPa, 14.86%, 2 364.48 MPa and 16.78 MPa, respectively. It had the characteristics of high strength, high modulusand high flexibility. The performance of TBMA cured epoxy resin was better than the existing curing systems of tung oil anhydride,tung maric anhydride and tung oil polyimide anhydride.