氮化钛含量对热塑性涂层光热效应及自修复性能的影响

Effects of Titanium Nitride Concentration on Photothermal Effects and Self-healing Properties of Thermoplastic Coatings

为了实现涂层破损的高效自修复,将纳米氮化钛与热塑性聚氨酯混合,制备了不同氮化钛含量的复合涂层。利用扫描电子显微镜(SEM)、X射线衍射仪(XRD)和紫外可见分光光度计(UV-Vis)分析了氮化钛的结构和光谱吸收特征;利用差示扫描量热仪(DSC)、热电偶、光学显微镜、扫描电子显微镜(SEM)、交流阻抗谱(EIS)等对复合涂层的热力学性能、光热转换性能、自修复性能及防腐性能进行测试。结果表明:基于纳米氮化钛的表面等离激元特性,在热塑性聚氨酯中添加质量分数为2%的氮化钛后,复合涂层具有良好的光热转换性能,在近红外激光照射后其表面温度高于聚氨酯的玻璃化转变温度。当涂层表面有划口时,通过激光照射可以提高涂层的局部温度,使聚合物分子链运动并流向划痕界面,复合涂层的结构和防腐性能均得到恢复,并且修复后涂层中氮化钛仍分布均匀。此外,氮化钛纳米颗粒还有助于填补涂层的微观孔隙,使复合涂层的防腐性能提高。

To achieve efficient self-healing of damaged coatings,nanosized titanium nitride(Ti N)and thermoplastic polyurethane(TPU)were mixed to prepare composite coatings with different Ti N contents.The structure and spectral absorption characteristics of Ti N were analyzed by SEM,XRD and UV-Vis spectroscopy(UV-Vis).Thermodynamic property,photothermal conversion performance,self-healing property and corrosion resistance of Ti N-TPU composites were tested by differential scanning calorimetry(DSC),thermoelectric couple,optical microscopy,SEM and electrochemical impedance spectroscopy(EIS).Results show that based on the surface plasmon property of Ti N,the composite coating exhibits desiable photothermal conversion performance after adding 2%Ti N into TPU,and its surface temperature is higher than the glass transition temperature of TPU under near infrared laser irradiation.When there is a scratch on the Ti N-TPU surface,its local temperature increases dramatically under laser irradiation,leading to the movement of polymer molecular chain and the self-healing of the scratched interface.The distribution of Ti N in the healed coating is still uniform.In addition,Ti N nanoparticles help to fill the microscopic pores of the coating and improve the corrosion resistance of the composite film.