Study on physical properties of poly(vinyl acetate) emulsion films obtained in batchwise and in semicontinuous systems

Abstract

AbstractEmulsion polymerization of vinyl acetate was carried out batchwisely or semicontinuously in the presence of a nonionic surfactant or poly(vinyl alcohol) (PVA). From the investigation of degrees of polymerization of poly(vinyl acetate) (PVAc) during the course of polymerization and those of corresponding hydrolyzed PVA, it was clarified that the degrees of polymerization of the batchwise system are much larger than those of the semicontinuous system, and long branches and shorter branches are formed in the batchwise and the semicontinuous systems, respectively. The emulsion films obtained batchwisely had properties with better tensile strengths by two to four times (nonionic system) and 1.5 times (PVA system) than those obtained semicontinuously. The former films revealed a better water‐resistant nature compared with the latter films. © 1993 John Wiley & Sons, Inc.