热可逆聚氨酯改性自修复环氧树脂的力学性能和自修复行为

Mechanical Properties and Self-healing Behavior of Thermo-reversible Polyurethane-modified Self-healing Epoxy Resins

通过将热可逆聚氨酯引入基于Diels-Alder反应的自修复环氧树脂,成功制得热可逆聚氨酯改性自修复环氧树脂材料。热可逆聚氨酯的引入赋予自修复环氧树脂良好的抗弯性能、冲击韧性和自修复能力。当聚氨酯的添加量为20%时,得到的材料性能最佳。当改性材料在外界因素作用下出现裂纹、裂缝等损伤后,通过在130℃处理12 min及85℃处理24 h便可实现损伤的修复,并且可实现多次损伤的重复自修复。研究发现,多次重复自修复是通过热可逆Diels-Alder反应、分子链的热运动,以及氢键的解离和再生这三种作用协同实现。这些研究结果对制备具有良好冲击韧性的环氧树脂材料及其损伤的高效自修复具有重要的指导意义。

Athermo-reversible polyurethane-modified self-healing epoxy resin was manufactured successfully through introducing thermo-reversible polyurethane into Diels-Alder reaction-based self-healing epoxy resin.The bending behavior,impact toughness and self-healing performance of self-healing epoxy resin were reinforced prominently when thermo-reversible polyurethane was introduced.The thermo-reversible polyurethane-modified self-healing epoxy resin material exhibited the optimal performance when the introduced amount of thermo-reversible polyurethane was 20%.Cracks could be renovated by heat-treating at 130℃for 12 min and 85℃for 24 h once thermo-reversible polyurethane-modified self-hea-ling epoxy resin was damaged on account of external factors and cracks appeared.Moreover,the repair could be repeated.Results revealed that the repeated self-healing behavior was implemented by reason of synergistic effect of thermo-reversible Diels-Alder reaction,dissociation and regeneration of hydrogen bonds as well as thermal movement of molecular chains.The results had significant instruction for fabricating epoxy resin materials with both strong impact toughness and self-healing for micro-damages efficiently.