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

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'-dithiodipropionic 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.