环氧亚麻油与酸酐固化反应研究

Study on Curing Reaction of Epoxidized Linseed Oil with Anhydrides

环氧亚麻油是亚麻油通过环氧化反应合成的环氧树脂,其可进一步与固化剂反应,制备具有多种性能的热固性环氧树脂基复合材料,在多种领域具有广泛应用。文中研究了环氧亚麻油的固化反应,在选择最佳固化剂和促进剂的基础上,用正交试验优化反应条件,红外光谱表征固化反应过程,差示扫描量热法(DSC)研究固化反应的热力学特性。结果表明,环氧亚麻油固化反应的最佳固化剂是马来酸酐与邻苯二甲酸酐混合物(摩尔比0.83∶0.17),最佳促进剂是N,N-二甲基苄胺。影响固化反应各因素的主次顺序为:混合酸酐/环氧基配比>温度>促进剂用量>时间。在最佳固化条件下,即混合酸酐/环氧基配比为1.2∶1.0、促进剂用量为2.5%、温度为120℃、时间为4 h时,产物固化度可达97.13%。随着固化反应的进行,环氧基和酸酐红外特征吸收逐渐消失,固化反应趋于完全;环氧亚麻油/混合酸酐固化反应为放热反应,峰顶温度为182.6℃,反应热焓为-130.2 J/g。

Epoxidized linseed oil is a type of epoxy resin synthesized by the epoxidation reaction of linsee d oil. Thermosetting epoxy resin-based polymer composites with a variety of properties can be prepared after the reaction of epoxy resin and curing agents, which can be used in many fields. In this work, the curing reaction of epoxidized linseed oil was studied and the optimized reaction conditions were also obtained by the application of orthogonal experimental method based on the best selection of curing agent and accelerator. Fourier transform infrared spectroscopy（FT-IR）and differential scanning calorimetry （DSC）techniques were applied to investigate the curing reaction process and characterization. The results show that a mixture of maleic anhydride and phthalic anhydride （molar ratio 0.83﹕0.17） was the best curing agent while N, N-dimethylbenzylamine was the best accelerator. The factors impacting curing reaction were in the order of mixed anhydride/epoxy ratio 〉 temperature 〉amount of accelerator〉time. Curing degree of the final product could reach 97.13% under the following optimized conditions：mixed anhydride / epoxy ratio was 1.2﹕1.0 （molar ratio）, the amount of accelerator was 2.5%, the temperature and time were 120 ℃ and 4 h,respectively. IR characteristic absorption of epoxy and anhydride gradually disappeared as the proceeding of the reaction and the curing reaction tended to be complete. Curing reaction of epoxidized linseed oil with mixed anhydride is an exothermic one with peak temperature at 182.6 ℃ and reaction enthalpy is -130.2 J/g.