基于交联键稳定性设计的低温快速自修复聚氨酯超分子构筑及柔性应变传感应用

自修复超分子作为一种新型柔性材料，在柔性电子新科技中受到高度重视。目前该类材料的主要瓶颈问题为交联键强度、超分子网络刚度等因素相互牵制导致材料在低温环境下的自修复能力和力学性能无法被同步提高。为此，研究者提出了关键在于革新交联键设计观念的新思路。本项目拟开发兼具低温快速自修复能力和优异力学性能新型聚氨酯超分子材料，探究利用交联键热力学和动力学稳定性特征促进低温环境下超分子网络强度和动态特性。通过考察材料的分子量分布，交联密度，分子链迁移与超分子自修复能力和力学性能的相互关系，揭示交联键稳定性促使超分子低温自修复能力和力学性能提高的原理。通过建立动态交联键的能量耗散机制，探讨低温环境下交联键断裂/再形成和分子链迁移的关键过程，探明低温自修复机理，研究出在-20℃下兼具快速自修复能力和优异力学性能的超分子，为长寿命、高稳定性柔性传感器的研制提供理论依据和技术指导。

As a new type of flexible materials, self-healing supramolecules have attracted much attention in the new technology of flexible electronics. At present, the main bottleneck problem of this kind of materials is that the cross-linking bond strength, supramolecular network stiffness and other factors mutually restrict the self-healing ability and mechanical properties of materials in low temperature environment, which cannot be improved simultaneousl. Therefore, the researcher put forward a new idea that the key lies in innovating the design of cross-link key. In this project, a new polyurethane supramolecular material with low temperature rapid self-repairing ability and excellent mechanical properties is developed. The thermodynamic and kinetic stability characteristics of cross-linked bonds are explored to promote the strength and dynamic characteristics of supramolecular networks in low temperature environment.The relationship between molecular weight distribution, crosslinking density, molecular chain migration rate and supramolecular self-repair ability and mechanical properties was investigated. The principle that the stability of crosslinking bond promotes the improvement of supramolecular low temperature self-repair ability and mechanical properties was revealed. By establishing the energy dissipation mechanism of dynamic crosslinking bond, exploring the key process of crosslinking bond fracture/re-formation and molecular chain migration in low temperature environment, exploring the mechanism of low temperature self-repair, and studying the supramolecular with fast self-repairing ability and excellent mechanical properties under -20℃studied, which provides theoretical basis and technical guidance for the development of long life and high stability flexible sensors