一种基于亚胺键的兼具阻尼和自修复性能的聚氨酯材料

A Polyurethane Material with Both Damping and Self-Healing Properties Based on Imine Bonding

以乙二胺和水杨醛为原料,合成了具有双亚胺键结构的芳香类化合物乙二胺席夫碱(ESS),红外光谱和核磁对其结构进行了表征,证明该化合物成功合成。然后以ESS为扩链剂制备了聚氨酯(EPU),采用红外光谱分析了其结构组成,热失重分析和动态力学热分析研究了聚氨酯的热稳定性及阻尼性能,利用力学性能测试及光学显微观察对自修复性能进行表征,分析了亚胺键以及不同添加比例对聚氨酯性能的影响。结果表明,EPU的有效阻尼温域可达到-5~100℃。根据时温等效原理,有效频率范围可以外推至0.1~103Hz,表现出优异的阻尼性能。EPU具有优异的力学性能,拉伸强度为11.97~16.89 MPa,断裂伸长率为726%~498%。同时EPU在温和的刺激条件下表现出良好的自修复性能,40℃修复12 h,可恢复87.9%的力学性能。60℃修复5 min,表面划痕可以愈合,在酸性条件下,EPU的修复能力更好。

The aromatic compound ethylenediamine Schiff base(ESS)with double imine bond structure was synthesized using ethylenediamine and salicylaldehyde as raw materials,and the structure was characterized by IR spectroscopy and NMR,which proved the successful synthesis of the compound.Then,a polyurethane sample(EPU)was prepared using ESS as chain extender.The structural composition was analyzed by infrared spectroscopy.The thermal stabilities and damping properties of the polyurethane were investigated by heat loss analysis and dynamic thermo-mechanical analysis.The self-repairing properties were characterized by mechanical property test and optical microscopic observation.The effects of imine bonding and different additive ratios on the properties of the polyurethane were analyzed.The results indicate that the effective damping temperature range of the EPU samples can be extended from-5℃to 100℃.Following the principle of time-temperature equivalence,the effective frequency range can be extrapolated to 0.1~103 Hz,demonstrating excellent damping performance.With the tensile strengths of 11.97~16.89 MPa and elongation at break of 726%~498%,the EPU samples show excellent mechanical properties.Meanwhile,the EPU material demonstrate excellent self-repairing capabilities under mild stimulation conditions.Specifically,87.9%of its mechanical properties are recovered after being repaired at 40℃for 12 h.Additionally,surface scratches are effectively healed after being repaired at 60℃for 5 min.Notably,the repairing ability of the EPU material is found to be superior under acidic conditions.