石墨烯-热可逆自修复聚氨酯复合膜的制备和性能

Preparation and Properties of Graphene-thermoreversible Self-healing Polyurethane Composite Film

以糠胺和双马来酰亚胺Diels-Alder(DA)反应单体,通过两步合成法合成具有DA键的热可逆聚氨酯(PU),然后通过溶液共混和流延成膜工艺将石墨烯(G)引入到DAPU体系中制备DAPU-G自修复复合膜,研究了复合膜的微观结构、热学、力学、介电性能以及红外热修复性能等。实验结果表明,复合膜中石墨烯质量分数在0.4%~1.5%范围内,低含量的石墨烯可实现在DAPU中均匀分布,高石墨烯含量易形成团聚体;石墨烯改善了复合膜的热学稳定性,且随着石墨烯含量增加,复合膜的拉伸强度先增加后逐渐下降,而介电常数逐渐增加,电导率随着频率的增加逐渐增加,但与石墨烯的含量的关系不大,所有的复合膜几乎没有导电性。石墨烯含量在0.4%~1.5%范围内的复合膜经红外光热处理5 min,表面划痕未实现完全热自修复,红外光热处理10 min且石墨烯含量在0.7%~1.5%范围内的复合膜实现了完全热自修复,说明石墨烯改善了复合膜的红外光热修复性能。

Diels-Alder(DA)thermoreversible reaction polyurethane(PU)was synthesized by two-step synthesis from furfuramine and bismaleimide reaction monomers.Then graphene(G)sheets were introduced into DAPU solution by mixing and tape casting process to prepare G-DAPU self-healing composite film.The microstructure,thermal,mechanical,dielectric properties and infrared thermal self-healing properties of the composite film were studied.The experimental results show that the mass content of graphene in the composite film is in the range of 0.4%~1.5%,graphene with low mass content can be uniformly distributed in DAPU,and the graphene with high mass content is easy to form aggregates.Graphene improves the thermal stability of the composite film,and with the increase of graphene mass content,the tensile strength of the composite film first increases and then decreases,while the dielectric constant gradually increases,and the conductivity gradually increases with the increase of frequency,but it has little relationship with the mass content of graphene,and all composite films have almost no conductivity.The composite film with graphene contents in the range of 0.4%~1.5%does not achieve complete thermal self-healing after infrared photothermal treatment for 5 minutes.The composite film with graphene content in the range of 0.7%~1.5%after infrared photothermal treatment for 10 minutes could achieve complete thermal self-healing,indicating that graphene improves the infrared photothermal healing performance of the composite film.