Abstract:

The fluoropolyurethane dimethacrylate (TFXPUA) macromonomer was prepared firstly. Then, the fluorinated polyurethane microcapsules (MTFXPUA) were prepared by interface polymerization with TFXPUA, 1,6-hexanediol diol acrylate (HDDA) and 2-hydroxy-2-methyl-1-phenyl-1-propanone(HMPP) as the core materials, and polyurethane as the wall material. MTFXPUA were added to waterborne polyurethane to prepare self-repairing films and coatings. The structure and properties of TFXPUA, MTFXPUA and the repaired polyurethane were characterized by Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC), scanning electron microscopy (SEM), particle size analysis (PSA), contact angle test, tensile testing, salt water immersion test and electrochemical impedance. The results showed that TFXPUA macromonomer was prepared successfully and its number average molecular weight was 14275. The average particle size of fluorinated polyurethane microcapsules (MTFXPUA) based on TFXPUA as the core material was 24.05μm. The scanning electron microscope indicated that MTFXPUA had a good self-repairing effect on microcracks in polyurethane coating. With the increase of tetrafluoro benzenedimethanol (TFB) content in TFXPUA, the contact angle at the self-repairing site, tensile strength, impedance at low frequency and the radius of Nyquist curve of the waterborne polyurethane repaired by MTFXPUA increased. When TFB content exceeded 6%, the increase trend slowed down. When the amount of TFB was 6%, the water contact angle at the repair site could reach 96.80° and the tensile strength of the repaired film increased from 17.94MPa to 25.21MPa. Microcapsules based on fluoropolyurethane dimethacrylate (TFXPUA) macromonomer had good self-repairing performance for polyurethane coatings and realized the secondary protection of the repaired area.

Key words: fluorine polyurethane-acrylate, macromer, microcapsules, self-repairing, coating

摘要：

首先自制了含氟聚氨酯二甲基丙烯酸酯（TFXPUA）大单体，然后采用界面聚合法制备了以TFXPUA、1,6-己二醇二丙烯酸酯（HDDA）、2-羟基-2-甲基-1-苯基-1-丙酮（HMPP）为芯材，聚氨酯为壁材的含氟聚氨酯微胶囊（MTFXPUA），再将其添加到水性聚氨酯中制备自修复涂膜及涂层。通过红外光谱（FTIR）、凝胶渗透色谱（GPC）、扫描电镜（SEM）、粒度分析（PSA）、接触角测试、拉伸试验、耐盐水浸泡实验以及电化学阻抗测试表征了TFXPUA以及MTFXPUA的化学结构、微观形貌、自修复及力学等性能。结果表明：含氟聚氨酯二甲基丙烯酸酯（TFXPUA）大单体成功制备，其数均分子量为14275。基于TFXPUA为芯材制得的含氟聚氨酯微胶囊（MTFXPUA）平均粒度为24.05μm，SEM结果表明MTFXPUA微胶囊在聚氨酯涂层中对微裂纹进行了良好自修复，随着TFXPUA中四氟对苯二甲醇（TFB）用量增加，MTFXPUA的修复处接触角、拉伸强度、在低频处阻抗值、Nyquist曲线半径呈现增大的趋势; 当TFB用量超过6%时，增加趋势变缓。TFB用量为6%时，修复处的接触角可达96.80°，修复后涂膜拉伸强度由17.94MPa增加到25.21MPa，基于含氟聚氨酯二甲基丙烯酸酯（TFXPUA）大单体制备的微胶囊对聚氨酯涂层具有良好的自修复性能，实现了对修复后材料的二次保护。

关键词: 含氟聚氨酯-丙烯酸酯, 大单体, 微胶囊, 自修复, 涂层