超高分子量聚乙烯/石墨烯复合涂层制备及其在海洋装备防护中的应用

Flame Sprayed UHMWPE/Graphene Nanosheet Composite Coatings for Marine Applications

目的采用热喷涂技术制备涂层,通过材料选择和结构设计,有效延缓海水对金属基底的腐蚀和冲蚀,并抑制海洋材料表面生物污损等对海洋材料的严重破坏。方法采用高能球磨法制备了聚乙烯-石墨烯(UHMWPE-graphene)复合粉末,用火焰喷涂技术在E235B碳钢基底表面制备UHMWPE和UHMWPE-graphene复合涂层。通过扫描电子显微镜和透射电子显微镜对原始粉末和涂层微观组织进行表征,并通过摩擦磨损实验、电化学测试、生物污损检测,分别评价涂层耐海水冲刷性能、耐腐蚀性能以及抗生物污损特性。结果相对于碳钢和UHMWPE涂层,UHMWPE-graphene复合涂层的腐蚀电位提高和腐蚀电流减小,预示着样品的耐腐蚀特性增强。由于UHMWPE-graphene复合涂层呈现疏水性以及更低的表面能,使其表现出优异的抵抗海藻贴附的能力。添加石墨烯的复合涂层的摩擦系数和磨损率比纯UHMWPE涂层均有一定程度的降低。添加石墨烯质量分数为0.5%时,涂层的摩擦系数由0.236降低到0.195,且磨损率下降了约26%。结论利用火焰热喷涂技术在碳钢表面成功制备了组织致密的UHMWPE涂层、UHMWPE-0.2%graphene和UHMWPE-0.5%graphene复合涂层。石墨烯的添加,能够有效提高涂层在模拟海洋环境中的耐蚀性、抗生物污损性及耐磨性。

Marine corrosion, washout and biofouling are key problems to be resolved for marine infrastructures during their service process. Thermal spraying technology has been developed as one of surface protection methods. Thermal sprayed coat- ing can protect metal substrates against corrosion and washout effectively, and inhibit heavy damage from biofouling to marine materials based upon material selection and structural design. UHMWPE-graphene composite powder was prepared in the me- thod of high energy ball milling. UHMWPE and UHMWPE-graphene composite coatings were prepared on E235B carbon steel substrate by adopting flame spraying technology. Microstructure of original powder and as-deposited coatings was characterized by using scanning electron microscope （SEM） and transmission electron microscopy （TEM）. Seawater washout resistance, cot-rosion resistance and biofouling resistance of the coatings was evaluated by performing friction and wear experiment, electro- chemical test and biofouling test, respectively. Compared with carbon steel and UHMWPE coating, corrosion potential of UHMWPE-graphene composite coatings increased while corrosion current decreased, indicating that corrosion resistance cha- racteristic of the sample was enhanced. Since UHMWPE-graphene composite coatings exhibited hydrophobicity and lower sur- face energy, it has excellent resistance to seaweed adhesion. Friction coefficient and wear rate of grapheme-doped composite coatings were lower than that of pure UHMWPE coating. For the coating containing 0.5wt.% grapheme, friction coefficient de- creased from 0.236 to 0.195, and wear rate decreased by nearly 26%. Compact UHMWPE coating, UHMWPE-0.2% graphene and UHMWPE-0.5% grapheme composite coatings are successfully prepared on carbon steel by adopting flame spraying tech- nology. Addition of grapheme can effectively improve corrosion resistance, boifuuling resistance and wear resistance of the coatings in simulated marine environment.