Preparation And Application Of Flexible Self-healing Film Material Based On Imine Bond

With the widely applications in wearable displays,thin film solar cells and other organic and mechanical devices,flexible conductive materials are gradually becoming the hotspot in electronics industry.However,the soft nature of the flexible conductive material also makes it susceptible to mechanical damage,leading to the loss of their good electrical conductivity.It is an effective means to improve the stability and service life of flexible conductors by endowing them with self-healing properties.Generally,self-healing flexible conductors can be achieved by incorporating self-healing polymers and conductive nanomaterials.The mechanical properties,thermodynamic properties and self-healing properties of self-healing polymers have a great influence on the mechanical properties and self-healing properties of flexible conductors.Therefore,the design and optimization of the components and structure of self-healing polymers are very important.This paper focuses on the performance regulation and the preparation of self-healing polymer materials,and combines the silver nanowires with good conductivity to prepare flexible conductors with good self-healing ability.The specific work was as follows:In this paper,three kinds of polyimine films were prepared by the reaction of pbenzaldehyde and triamine with 1,6-hexane ediamine,1,8-octyl ediamine and 1,2-diethane respectively,which were named PI-H,PI-D and PI-B.The imine bond in polyimine films was confirmed by infrared spectroscopy.The gel fractions of the three polyimine films were97.95%,97.91% and 87.27%,which proved that all the polyimine films formed a threedimensional cross-linking network structure.The mechanical properties results showed that PI-H with high crosslinking density exhibit high tensile strength(21 MPa),storage modulus(1.7 GPa)and low elongation at break(15%).On the contrary,PI-H with flexible chain exhibited general tensile strength(10.5 MPa),storage modulus(1 GPa)and good elongation at break(55.7%).All of the three polyimine films can completely self-repair and reshape at low temperature and pressure(105 °C,2MPa)in 2h.In this paper,three kinds of Ag NWs/polyimine composites were prepared by deposition of silver nanowires on the surfaces of PI-H,PI-D and PI-B,respectively.The as-prepared composites were named as PI-Ag NWs-H,PI-Ag NWs-D and PI-Ag NWs-B,respectively.The good elasticity and mechanical performance of PI-B endowed the PI-Ag NWs-B with the capability of maintaining its conductance after undergoing multiple and high degrees of deformations.The conductivity of PI-Ag NWs-B can be restored completely.In addition,the as-prepared flexible and healable PI-Ag NWs-B maintained its conductance even after multiple cycles(e.g.,6 cycles)of the cutting-healing process and exhibited a negligible conductivity decrease(<5%).Finally,the self-healing mechanism of the composites was revealed by observing the SEM image of the surface morphology of the healed Ag NWs/polyimine composites.