Preparation and properties of waterborne polyurethane/self-cross-linkable fluorinated acrylic copolymer hybrid emulsions using a solvent/emulsifier-free method

Abstract

A series of waterborne polyurethane (WBPU)/fluorinated self-cross-linkable acrylic copolymer hybrids (WBPU/FPA) emulsions were successfully prepared by solvent/emulsifier-free prepolymer mixing process. This study focused on the effect of vinyl triethoxysilane (VTES, 0–15 wt%)/butyl acrylate (BA, 15–0 wt%) weight ratio on the properties of WBPU/self-cross-linked fluorinated acrylic copolymer hybrids for high-performance water-repellent coating materials. As the VTES content increased, the particle size of hybrid emulsion decreased; however, the viscosity of the emulsion increased. The glass transition temperature Tgα, tensile modulus, storage modulus, and hardness increased with increasing VTES content. The surface tension of film sample decreased with increasing VTES content up to about 9 wt% and then levelled off. The tensile strength and water/methylene iodide contact angles of film sample increased with increasing VTES content up to about 9 wt% and then almost levelled off. The optimum VTES/BA weight ratio was found to be about 9:6 wt% to obtain high-performance water-repellent coating materials.