织物上自清洁涂层的制备及性能

Preparation and properties of a self-cleaning coating on fabrics

采用乳液聚合法合成了聚苯乙烯(PS)微球乳液,以此作为形成微纳米结构的基料,然后与作为低表面能材料的端羟基全氟聚醚(PFPE)以及作为交联剂的六亚甲基二异氰酸酯(HDI)三聚体混合,制备了疏水疏油剂。以简单的浸涂方式用它来整理棉布,然后在80°C下预烘30 min再烘干,赋予了棉布优异的自清洁功能。考察了微球乳液用量、氟醚用量、烘干温度以及烘干时间对涂层性能的影响,得到最优的涂层制备条件为:PS微球乳液、PFPE、HDI三聚体的质量比2.00∶2.00∶1.86,烘干温度140°C,烘干时间60 min。棉布表面水、二碘甲烷和大豆油的接触角分别为145.7°、126.4°和124.2°,它们的滚动角依次为29.9°、29.7°和40.6°。经过洗涤或磨损,棉布表面的接触角不变。滴上98%H2SO4和60%KOH溶液后3 min内没有变化。

An emulsion of polystyrene（PS） microspheres being able to form a micro-nano structure on a surface was synthetized by emulsion polymerization, and then mixed as the binder with hydroxyl-terminated perfluorinated polyether（PFPE） having low surface energy and hexamethylene diisocyanate（HDI） trimer as crosslinking agent to make an omniphobic material, which was used to treat the cotton fabrics by a simple dip-coating method. The coated cotton fabrics show an outstanding self-cleaning performance after preheated at 80 °C for 30 min and then dried thoroughly. The effects of the contents of microspheres emulsion and PFPE, as well as drying temperature and time on the properties of coating were studied. The optimal preparation conditions were obtained as follows： mass ratio of PS microspheres emulsion to PFPE to HDI trimer 2.00：2.00：1.86, drying temperature 140 °C, and drying time 60 min. The contact angle of the coated cotton fabric is 145.7° to water, 126.4° to diiodomethane, and 124.2° to soybean oil. The sliding angles of water, diiodomethane, and soybean oil are 29.9°, 29.7°, and 40.6°, respectively. The contact angles of the coated cotton fabric change slightly after being washed or worn. The surface of a self-cleaning cotton fabric is unchanged after dropping 98% H2 SO4 and 60% KOH solutions on it within 3 min.