Water-based, heat-assisted preparation of water-repellent cotton fabrics using graft copolymers†
An inexpensive, facile, environmentally-friendly, water-based method to prepare water repellent cotton fabrics using non-fluorinated graft copolymers is reported. A series of graft copolymers, poly[(oligo(ethylene glycol) methacrylate)-co-(2-hydroxyethyl methacrylate)-co-(n-butyl methacrylate)-co-(methyl methacrylate)]-graft-poly(dimethylsiloxane), were synthesized. The oligo(ethylene glycol) methacrylate component was incorporated to impart water dispersibility to the polymer, the 2-hydroxyethyl methacrylate component facilitated polymer crosslinking around the cotton, while the grafted poly(dimethylsiloxane) provided water repellency. Cotton swatches were dipped into aqueous polymer micellar solutions, removed from the solutions, and then thermally annealed to produce robust water-repellent coatings. The water repellency improved with an increase in the polymer concentration of the coating dispersion, coating annealing temperature and time. The laundering durability of the coating improved as the graft copolymer backbone length and the PDMS content increased.