Preparation of water-repellent cotton fabrics from fluorinated diblock copolymers and evaluation of their durability

Two fluorinated diblock copolymers were prepared, characterized, and used to coat cotton fabrics. These copolymers included poly2-(perfluorohexyl)ethyl acrylate]-block-poly(triisopropyloxysilyl)propyl methacrylate] (PFHEA-b-PIPSMA) and poly2-(perfluorohexyl)ethyl acrylate]-block-poly(glycidyl methacrylate) (PFHEA-b-PGMA). The PFHEA block provided the coatings with a low surface tension to help impart water-repellency, while the PIPSMA or PGMA blocks (bearing alkoxysilane or epoxide groups, respectively) allowed the anchoring of the copolymers onto the cotton fibers. A simple coating procedure was used to yield water-repellent cotton fabrics. Water contact angles were measured to evaluate the durability of the treated cotton fabrics after they had been subjected to extraction, washing and laundry tests. These results revealed that cotton fabrics coated with PFHEA-b-PIPSMA were rendered hydrophobic, but their stability was relatively poor. Meanwhile, cotton fabrics coated with PFHEA-b-PGMA exhibited water contact angles higher than 150° and retained their water-repellency even under harsh test conditions.