Acceleration Effect of Dynamic Covalent Chains in a Hard Epoxy Resin on Its Thermally Induced Deformation and Healing Behavior

作者：Jiajia Fu, Yang Zhao, Lei Zhang, Feiya Fu, Xiangdong Liu · 发表于：Macromolecular Materials and Engineering · 年份：2021 · DOI：10.1002/mame.202100037 · 被引用次数：9 · 研究领域：Polymer composites and self-healing、Conducting polymers and applications、Advanced Polymer Synthesis and Characterization

Abstract The dynamic covalent chain polyester oligomer PCG5 is prepared and applied to epoxy thermoset. Preliminary tests including pattern stamping, healing, shape memory, indentation, and adhesion test of the cured epoxy resin show that PCG5 can accelerate deformation, crack‐healing, and transesterification rates at high temperatures. The transesterification rate and activation energy are quantitatively determined by a newly developed TGA method in the authors' group. This method is used to further realize a virtual acceleration mechanism of PCG5 in the transesterification reaction with cured epoxy resins, pointing out that the increase in cross‐link density and ester concentration improves the mobility of structure units and collision of ester groups. Moreover, introduction of PCG5 doesn't sacrifice glass transition temperatures ( T g ) of the cured epoxy resin and strengthens the fiber composites. An 85% recovery in storage modulus and an 88% recovery in tensile strength are achieved after 10 000 cycle's fatigue tests.