含双重动态共价键的松香基环氧类玻璃高分子的制备与性能

Fabrication and Properties of Rosin-based Epoxy Vitrimer with Dual Dynamic Covalent Bonds

以天然松香衍生物为刚性环氧单体,3,3’-二硫代二丙酸(DTDPA)为交联剂,通过环氧-羧基酯化反应固化,制备了含双重动态二硫键和酯键的生物松香基环氧类玻璃高分子网络.利用红外光谱和拉曼光谱对所得聚合物网络材料的结构进行了表征.结果表明,合成了含双重动态二硫键和酯键的松香基环氧高分子网络.对所有松香基环氧高分子网络进行了热机械性能、力学性能、热稳定性和应力松弛测试.结果表明,松香基环氧高分子网络具有高的热稳定性和力学性能,以及相对较快的应力松弛能力.此外,研究了交联剂添加量对所得松香基环氧高分子网络的自修复和再加工能力的影响.结果表明,DTDPA的羧基与松香环氧单体的环氧基摩尔比为100∶100的类玻璃(RE-100)网络具有最优的自修复和再加工性能.因为RE-100网络内部拥有最多的动态二硫键和酯键,在受到热刺激后,充足的动态二硫键和酯键发生可逆交换,促使网络快速重排,从而获得优异的自修复和再加工性能.

Herein,rosin-based epoxy vitrimers(RE)with dual-dynamic covalent bonds(disulfide bond and ester bond)were fabricated by epoxy-carboxylic acid reaction with rosin derivative as an epoxy monomer,3,3'-dithiodipro⁃pionic acid(DTDPA)as crosslinker.The structures of the RE networks were characterized by Fourier transform infrared spectroscopy(FTIR)and Raman spectroscopy,and the results indicated that rosin-based epoxy networks with dynamic disulfide bond and ester bond were successfully synthesized.Meanwhile,the thermo-mechanical properties,mechanical properties,thermal stability,and stress relaxation of the RE were investigated by dynamic mechanical analysis(DMA),tensile testing,and thermogravimetric(TG)analysis.Furthermore,the effects of DTDPA content on self-healing and reprocessing capabilities of the RE networks were researched.The results show that the Rosin-based epoxy vitrimer which was prepared at a molar ratio of carboxyl in DTDPA/epoxy groups in rosin monomer=100∶100(RE-100)possess the excellent self-healing and reprocessing capabilities due to the most dynamic disulfide bonds and ester bonds in the network.