石墨烯改性热可逆聚氨酯的多重响应自修复行为

Multi-responsive Self healing Behavior of Graphene modified Thermo-reversible Polyurethane

通过将石墨烯引入基于Diels-Alder动态键的热可逆聚氨酯,成功制备得到石墨烯改性自修复聚氨酯材料。石墨烯的引入,赋予自修复聚氨酯兼具热、近红外光和微波响应自修复功能。当添加石墨烯的质量分数为0.2%时,得到的材料力学性能最佳。当改性材料出现裂纹、裂缝等损伤后,通过在130℃处理10 min、或在250 W、808 nm近红外光照射30 s、或经500 W微波辐射2 min后,再分别于60℃处理12 h便可实现损伤的修复。其中,近红外光响应的自修复材料所需的修复时间最短、修复效率最高。研究发现,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3种作用协同实现。这些研究结果对于开发具有多重响应的自修复材料及其损伤的高效自修复具有重要的指导意义。

A thermo-reversible self-healing polyurethane was prepared successfully through introducing graphene into Diels-Alder reaction-based self-healing polyurethane.The polyurethane was endowed with thermal,near-infrared light and microwave responsive self-healing performance when graphene was introduced.The resultant thermo-reversible polyurethane exhibited the optimal mechanical performance when the introduced amount of graphene was 0.2%.Cracks could be renovated via heat-treated at 130℃for 10 min,or irradiated with 808 nm near infrared(NIR)light at 250 W for 30 s,or irradiated for 2 min with 500 W microwave together with kept for 12 h at 60℃.Moreover,the shortest repair time was needed and the highest repair efficiency could be reached when the damage was healed with NIR light irradiation.The results revealed that the self-healing behavior was implemented by synergistic effect of the thermo-reversible Diels-Alder reaction,thermal movement of molecular chains,and dissociation and regeneration of hydrogen bonds.These results had significant reference for developing multi-responsive self-healing materials and self-healing damages efficiently.