可紫外固化的水性聚氨酯耐沾污涂层  

UV-curable Waterborne Polyurethane Stain-resistant Coating

作　　者：罗海航 魏欢 华德诚 王忠辉[1] 范浩军[1,2] LUO Haihang;WEI Huan;HUA Decheng;WANG Zhonghui;FAN Haojun(The Key Laboratory for Leather Chemistry and Engineering of Ministry of Education,Sichuan University,Chengdu 610065,China;The State Key Laboratory of Polymer Materials Engineering,Sichuan University,Chengdu 610065,China)

机构地区：[1]四川大学皮革化学与工程教育部重点实验室,成都610065 [2]四川大学高分子材料工程国家重点实验室,成都610065

出　　处：《涂料工业》2024年第11期1-7,共7页Paint & Coatings Industry

基　　金：国家自然科学基金(22178238);浙江省尖兵领雁攻关计划(2022C01190)。

摘　　要：耐沾污涂层固化时需要长时间的高温烘烤,限制了其在热敏基材上的应用。为解决以上问题,以单端双羟基聚二甲基硅氧烷(PDMS)作为疏水组分,乙氧化三羟甲基丙烷三丙烯酸酯(EOTA)作为交联剂,制备了一种可紫外固化的水性聚氨酯耐沾污涂层。使用傅立叶变换红外光谱仪(FT-IR)、接触角测量仪、X射线光电子能谱仪(XPS)和原子力显微镜(AFM)等对涂层进行表征,同时对涂层进行了自清洁、防涂鸦和耐腐蚀测试。结果表明:作为支链的PDMS能够在固化时富集在涂层表面形成疏水层,使涂层水和二碘甲烷的接触角分别从(70.0±2.4)°/(33.6±2)°提高到(93.8±1.2)°/(62.2±1.1)°,降低了污染物的润湿和铺展性;交联剂EOTA的引入,一方面可有效包裹聚氨酯的极性基团,降低涂层表面极性,削弱污染物小分子与涂层间的相互作用力,因而水和油性液滴能够轻松地从涂层表面滑落,显示出涂层良好的自洁性;另一方面,致密的交联网络阻碍了油墨等污染物分子向聚合物骨架渗透,使得油墨等污染物停留在涂层表面并收缩成细小的液滴,很容易被纸巾擦拭干净,展现出涂层优异的防涂鸦性能。另外,涂层经过10%NaCl溶液5 d的浸泡,表面依然光滑平整并保持着防涂鸦性能,展现出涂层良好的耐腐蚀性和耐沾污持久性。The curing of stain resistant coatings requires a long period of high-temperature baking,which limits their application on thermosensitive substrates.In order to solve the above problems,a UV-curable waterborne polyurethane stain-resistant coating was prepared using single terminal dihydroxy polydimethylsiloxane(PDMS)as a hydrophobic component and ethoxytrimethylolpropane triacrylate(EOTA)as a cross-linking agent.The coating was characterised using Fourier transform infrared spectroscopy(FT-IR),contact angle measuring instrument,X-ray photoelectron spectroscopy(XPS)and atomic force microscopy(AFM),and was also tested for self-cleaning,anti-graffiti and corrosion resistance.It was found that PDMS,as a branched chain,was able to enrich on the surface of the coating during curing to form a hydrophobic layer,leading to an increase in the contact angle of the coating for water and diiodomethane from(70.0±2.4)°/(33.6±2)°to(93.8±1.2)°/(62.2±1.1)°,respectively,reducing the wetting and spreading of contaminants.On one hand,the introduction of cross-linking agents EOTA could effectively wrap around the polar groups of polyurethane and reduce the polarity of the coating surface,which weakened the interaction force between pollutant small molecules and the coating.As a result,water and oily droplets could easily slide off the surface of the coating without leaving any traces,and the coating showed good self-cleaning properties of the coating.On the other hand,the dense cross-linking network also prevented the penetration of contaminant molecules such as inks into the polymer backbone,making these inks and other pollutants stay on the surface of the coating and shrink into tiny droplets.The pollutant traces had been wiped away,showing good anti-graffiti performance of the coating.Not only that,after soaking in 10%NaCl solution for 5 days,the surface of the prepared coating was still smooth and maintained anti-graffiti properties,showing good corrosion resistance and stain-resistant durability of the coating.

关 键 词：水性聚氨酯 聚二甲基硅氧烷 紫外固化 耐沾污 涂层 

分 类 号：TQ637[化学工程—精细化工]