Physical properties of acrylic copolymer emulsions using poly(vinyl alcohol) as a protective colloid in comparison with those using surfactants

Properties of copolymer emulsions of methyl methacrylate and butyl acrylate prepared using poly(vinyl alcohol) (PVA) as a protective colloid have been studied and compared with those prepared using anionic and anionic/non-ion ic surfactants. The emulsions with PVA revealed a Newtonian flow, while tho se with surfactants had a thixotropic flow. Cast films of the emulsions wit h PVA afforded much larger tensile strengths, higher Young's moduli, and po orer resistance to water compared with those with surfactants. Adhesive lay er composed of the copolymers with PVA revealed markedly higher creep resis tance to shearing stress, while that with surfactants had poor resistance; these phenomena appear to arise from the canal-like morphology of PVA in th e former cast films, while the surfactants in the latter existed in island morphology. (C) 2000 Society of Chemical Industry.