两种线性自修复聚氨酯合成及修复性能

Synthesis and Repairing Properties of Two Linear Self-healing Polyurethanes

基于Diels-Alder反应分别利用甲苯二异氰酸酯、异氟尔酮二异氰酸酯与聚丙二醇、糠胺、双马来酰亚胺制备了两种不同硬段类型的线性自修复聚氨酯T–PUR–DA与I–PUR–DA。通过热重分析、差示扫描量热分析、凝胶–溶液–凝胶测试、拉伸测试、偏光显微镜观察等系统研究了T–PUR–DA与I–PUR–DA的热稳定性能、热可逆性能和自修复行为。结果表明,T–PUR–DA和I–PUR–DA组分浓度均在40~150℃范围内不发生变化,两种合成材料的软段玻璃化转变温度均低于室温,有利于分子链中动态热可逆共价键DA键的反应。I–PUR–DA的热处理循环能力(4次)优于T–PUR–DA的热处理循环能力(2次)。当呋喃基团与马来酰亚胺基团比值(F/M)增大时,T–PUR–DA和I–PUR–DA的强度和硬度呈下降趋势,其中F/M为1/1时自修复效率最佳。在80℃热处理6 h后自修复效率分别达到62%和71%,此外,两种聚氨酯均可在100℃恒温100 min完成材料自我修复。

Two kinds of linear self-healing polyurethane T–PUR–DA and I–PUR–DA with different hard segment types were prepared by Diels-Alder reaction using toluene diisocyanate,isophorone diisocyanate with polypropylene glycol,furfuryl amine,bismaleimide respectively.The thermal stability,thermal reversibility and self-healing behavior of T–PUR–DA and I–PUR–DA were systematically studied by thermogravimetric analyzer,differential scanning calorimeter,gel-solution-gel test,tensile test,polarized microscope,etc.The results show that species concentrations of T–PUR–DA and I–PUR–DA are constant within 40–150℃.Moreover,the soft segment glass transition temperature of the two synthetic materials is lower than room temperature,which is conducive to the dynamic reversible DA bond reaction in the molecular chain.Heat treatment cycle ability of I–PUR–DA(4 times)is better than that of T–PUR–DA(2 times).When the ratio of furan group to maleimide group(F/M)value increases,the strength and hardness of T–PUR–DA and I–PUR–DA show a downward trend,where F/M is 1/1,and the repair efficiency is the best.After heat treatment at 80℃for 6 h,the repair rates reached 62%and 71%respectively.In addition,the materials can be repaired at 100℃for 100 min.