自愈合聚氨酯的研究进展及其在柔性传感领域的应用

Research Progress on Self-Healing Polyurethane and Its Applications in the Field of Flexible Sensors

聚氨酯是一类常见的聚合物,因其具有出色的综合性能而受到了广泛关注。但是,对于聚氨酯而言,任何微小的损坏都会极大地缩短其使用寿命。因此,可以通过赋予聚氨酯自愈合性能来解决这一问题。聚氨酯的愈合机理中最常见的是内在驱动力,指的是通过分子结构设计,不需要外加愈合剂,使得聚氨酯的分子链自发运动重新缠结在一起。内在驱动通常分为可逆共价键(如二硫键、Diels-Alder反应、硼酸酯键等)和动态非共价相互作用(如氢键、离子键、金属配位键、主客体结构等)。聚氨酯主链中可以存在单一的内在驱动力,也可以同时存在多个内在驱动力共同作用。然而,自愈合聚氨酯仅仅具有自发修复损伤,延长其使用寿命并降低维护成本的这一优点仍不能满足聚氨酯在一些特殊场合的使用需求。为了进一步实现自愈合聚氨酯多场景的应用,在保留聚氨酯的自愈合性能的同时,考虑引入一些新的官能团,赋予聚氨酯一些特殊性能,如形状记忆、可降解、抗菌、生物相容等,实现自愈合聚氨酯的功能化集成。更重要的是,这些具有功能化的自愈合聚氨酯可以代替传统材料,作为柔性传感领域中的介电材料、基底材料或者封装材料,用于提高柔性传感器的可靠性和耐久性。因此,本文重点介绍了自愈合聚氨酯的自愈合机理,随后介绍了自愈合聚氨酯的功能化集成以及其在柔性传感领域的应用,最后在此基础上展望了自愈合聚氨酯的未来发展前景。

Polyurethane,a prevalent polymer,has garnered considerable attention owing to its exceptional overall performance within various applications.However,even minor damages can significantly curtail the service life of polyurethane.Consequently,a promising approach to address this challenge involves conferring self-healing properties upon polyurethane.Among the various healing mechanisms found in self-healing polyurethane,the intrinsic driving force stands out as the most common.This mechanism entails the spontaneous re-entanglement of polyurethane molecular chains through meticulous molecular structure design,obviating the necessity for external healing agents.Intrinsic driving force encompasses reversible covalent bonds(e.g.,disulfide bonds,Diels-Alder reactions,and boronic ester bonds)as well as dynamic non-covalent interactions(e.g.,hydrogen bonds,ionic bonds,metal coordination bonds,and host-guest interactions).The polyurethane main chain can possess a single intrinsic driving force or multiple intrinsic driving forces concurrently.Nevertheless,while self-healing polyurethane alone presents advantages in terms of extending service life and reducing maintenance costs through damage repair,it still falls short of meeting the usage requirements in certain specialized applications.To further enable the versatile application of self-healing polyurethane while preserving its self-healing properties,the incorporation of new functional groups becomes an enticing prospect.These functional groups can bestow specific properties upon polyurethane,such as shape memory,degradability,antibacterial properties and biocompatibility,thereby achieving functional integration within self-healing polyurethane.Importantly,these functionalized self-healing polyurethanes possess the potential to supplant traditional materials as dielectric materials,substrate materials,or encapsulation materials in the realm of flexible sensors.Consequently,they contribute to enhancing the reliability and durability of flexible sensors.Therefore,this article primarily focuses on elucidating the self-healing mechanism of self-healing polyurethane.Subsequently,it delves into the integration of functionality within self-healing polyurethane and its application within the field of flexible sensors.Lastly,based on these insights,the paper provides a glimpse into the future prospects for the development of self-healing polyurethane.