静电喷涂高附着力疏水涂层及其性能

目的提高静电喷涂疏水涂层的附着力。方法采用硅烷偶联剂和聚二甲基硅氧烷制备了表面改性疏水二氧化硅粉末。将一定比例的聚偏氟乙烯粉末、超高分子量聚乙烯粉末与疏水二氧化硅粉末混合,制备了复合型疏水粉末。使用环氧树脂、固化剂、活性剂等配制了导电环氧树脂。通过静电喷涂工艺将复合疏水粉末喷涂到已用导电环氧树脂覆盖的铝基板表面,经过中温固化,制得了铝合金疏水复合涂层。采用扫描电子显微镜(SEM)、傅里叶变换红外光谱仪(FTIR)、接触角测量仪(CA)、百格刀附着力测试仪等,对疏水复合涂层进行测试表征。结果 SEM结果表明涂层表面构建了微米-纳米的阶层粗糙结构,经CA测试,该表面具有较好的疏水性。当混合粉末中聚二甲基硅氧烷改性二氧化硅的比例占到20%时,环氧基疏水涂层的接触角最高可达到140°,滚动角最低可达5°,附着力的等级为0级,同时疏水涂层的耐磨性和耐腐蚀性良好。结论采用简单、易于工业化的静电喷涂工艺制备了高附着力的疏水涂层,具有广泛的应用前景。

High Adhesion Hydrophobic Coating by Electrostatic Spraying and Properties

The work aims to improve the adhesion of hydrophobic coating by electrostatic spraying. Hydrophobic silica powder was prepared by surface modification of silane coupling agent and poly two methylsiloxane. Mixed hydrophobic powders were prepared by mixing a certain proportion of polyvinylidene fluoride (PVDF) and ultra-high molecular weight polyethylene (UHMWPE) with hydrophobic silica powder. Epoxy resin, curing agent and active agent were used to prepare the conductive expoxy resin. Hydrophobic composite coatings of aluminum alloy were prepared by electrostatic spraying on the surface of aluminum substrate covered with conductive epoxy resin. The hydrophobic composite coatings were tested and characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, contact angle tester and Bagram knife adhesion tester. From SEM results, the coating surface had a micro-nano hierarchical rough structure, and the modified surface had good hydro-phobicity by CA test. When the proportion of polydimethylsiloxane modified silica in the mixed powders was 20%, the contact angle of epoxy-based hydrophobic coatings reached 140°, the rolling angle reached 5°, and the adhesion grade was 0. At the same time, the hydrophobic coatings had good wear resistance and corrosion resistance. Hydrophobic coatings with high adhesion are prepared by simple and industrialized electrostatic spraying process and has a wide application prospect.