Durable and soap-free fluorinated amphiphilic copolymer coatings for stainproof and soil release fabrics

The excessive use of laundry detergents has rendered surfactants in laundry wastewater a significant threat to ecological sustainability. Increasing attention has been directed toward fluorinated amphiphilic copolymers (FACs), which impart stainproof and soil release properties to fabrics, thereby reducing the need for detergent usage. This paper describes the preparation of two soap-free FAC emulsions, H and H + G, through solution polymerization followed by solvent displacement. The incorporation of ionic and cross-linking monomers results in limited surface reconstruction of the coatings when exposed to water. However, the strong hydrophilicity of ionic monomers promotes excellent water-induced surface hydrophilism (Δγ_s-H = 2.07 mN/m, Δγ_s-H+G = 1.60 mN/m). Upon studying the finished fabrics, the beneficial effects of the auxiliary monomer were reaffirmed. H + Linker exhibited the best overall properties, with its coating evenly distributed across the fabric fibers without substantially blocking the inter-fiber gaps. Fabrics coated with H + Linker demonstrated excellent stainproofing, soil release performance, and washing resistance (for corn oil, S.R.R._5-cotton = 4+, S.R.R._{5-polyester pongee} = 4−), as well as outstanding wear resistance (the water contact angle remained above 136° after 200 wear cycles). Analysis of fabric stain penetration led to a summarized mechanism for soil release: first, the coating must uniformly cover the fabric fibers to block external dirt; secondly, the coating surface must achieve the water-induced hydrophilization, facilitating improved cleaning. This mechanism underscores the validity of developing FACs to create durable, soap-free coatings for stainproof and soil release fabrics, which can satisfy practical application needs and mitigate the excessive use of surfactants.