UPDHES电泳涂层材料的制备及其防腐性能

Preparation and Corrosion Resistance of UPDHES Electrophoretic Coating

目的研究电泳沉积条件及光交联对沉积胶束制备涂层形貌、性能的影响。方法首先通过自由基聚合制备可光交联双亲性丙烯酸酯共聚物(UPDHES),通过全反射红外、氢核磁共振(1H-NMR)对共聚物进行结构表征。然后,将可光交联双亲性丙烯酸酯共聚物在选择性溶剂中自组装形成胶束纳米粒子溶液,利用纳米粒度分析仪、透射电子显微镜(TEM)对胶束粒子的粒径和形貌进行表征。最后,以上述胶束溶液为沉积液,控制不同沉积条件,通过电泳沉积在316L不锈钢表面制备光交联涂层,利用扫描电子显微镜(SEM)、原子力显微镜(AFM)研究了电泳沉积条件及光交联对涂层形貌及性能的影响。同时,通过电化学工作站研究不同条件制备的涂层在1 mol/L HCl中的耐腐蚀性能。结果当沉积电压为5 V、沉积时间为3min时,电泳沉积制备的涂层表面光滑,具有较好的致密性和均一性,此时涂层的自腐蚀电位为-0.36 V,远高于不锈钢(-0.43 V),耐腐蚀性能最优。光交联后,涂层的附着力由2级增加至1级,自腐蚀电位增加至-0.34 V,耐腐蚀性进一步提高。结论电泳沉积胶束制备光交联涂层过程中,沉积时间、沉积电压均存在一最优值,此时制备的涂层结构完整,耐腐蚀性能最好。光交联可进一步提高涂层的耐腐蚀性能。

The work aims to study effects of electrophoretic deposition condition and photo-crosslinking on morphology and properties of coatings prepared by electrodepositing micelles. Firstly, photo-crosslinkable amphiphilic acrylate copolymer （UPDHES） was synthesized by radical polymerization. Its structure was characterized with nuclear magnetic resonance spec-trometer （1H-NMR） and Fourier transform infrared spectroscopy. Micelles nano particle solution was obtained through UPDHES self-assembly in selective solvent. Then particle size and morphology of micelles were characterized with nanometer particle size analyzer and TEM. With the micellar solution as electrolyte, photo-crosslinkable coating was prepared on the sur-face of 316L stainless steel by electrodeposition. Effects of electrodeposition condition and photo-crosslinking on coating mor-phology and properties were studied with SEM and atomic force microscope （AFM）. Corrosion resistance of coatings prepared under different conditions in 1 mol/L HCl was studied with electrochemical workstation. When electrodeposition voltage was 5 V and electrodeposition time was 3 min, the coating prepared by electrophoretic deposition exhibited good smoothness, com-pactness and uniformity, self-corrosion voltage increased to –0.36 V, considerably higher than that of stainless steel （？0.43 V）, and the corrosion resistance was the best. After photocrosslinking, adhesion of the coating increased from grade 2 to grade 1, self-corrosion potential increased to？0.34 V and corrosion resistance further increased. For deposition time and deposition vol-tage, there is an optimum value which endows the photocrosslinked coating prepared by electrodepositing micelles with com-plete structure density and good corrosion resistance; photo-crosslinking can further improve corrosion resistance of the coating.