Masato Nakamae

Preparation of polymer emulsions using a poly(vinyl alcohol) as protective colloid

Abstract We have prepared poly(vinyl acetate) (PVAc) emulsions using a new modified fully hydrolyzed poly(vinyl alcohol) (PVOH) with hydrophobic groups (RS-POLYMER) as a protective colloid. The stability of emulsion polymerization was excellent and the emulsion concurrently resulted in a good viscosity stability at low temperatures and high water resistant film; which could not be achieved by using a conventional PVOH. The features of the emulsion are ascribed to the characteristics of RS-POLYMER, which are stable at low temperatures and have a high water resistance. The emulsion has the advantage that it can be applied in high wet strength adhesives for paper and wood use.

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-ionic surfactants. The emulsions with PVA revealed a Newtonian flow, while those with surfactants had a thixotropic flow. Cast films of the emulsions with PVA afforded much larger tensile strengths, higher Youngs moduli, and poorer resistance to water compared with those with surfactants. Adhesive layer composed of the copolymers with PVA revealed markedly higher creep resistance to shearing stress, while that with surfactants had poor resistance; these phenomena appear to arise from the canal-like morphology of PVA in the former cast films, while the surfactants in the latter existed in island morphology. © 2000 Society of Chemical Industry