A polyurethane/polyacrylate (PUA) composite emulsion was synthesized by using polyurethane (PU) as seeds with soap-free emulsion polymerization, in which methyl methacrylate (MMA) and butyl acrylate (BA) were used as main acrylic monomers. The effect of acrylic contents and "stiff" and "soft" weight ratio of acrylic monomers on the properties of the films were investigated. The Fourier transform infrared (FTIR) results showed that acrylic monomers were involved in the emulsion copolymerization. The optimum composition of PUA composite formation was obtained when the polyacrylate (PA) content was 20%, in which the weight ratio of MMA and BA was 2/1. With the increment of PA content, the decomposition temperature increased.

Keywords: polyurethane/polyacrylate composite emulsion; acrylic content; "stiff" and "soft" weight ratio