Poly(vinyl alcohol) - Poly(vinyl acetate) composite films from water systems: Formation, strength-deformation characteristics, fracture

Abstract

The object of investigation was thin (< 200 μm) films, formed by casting from water based mixtures of poly(vinyl alcohol) (PVA) water solution and poly(vinyl acetate) (PVAc) water suspension. Starting systems hence were suspensions of plasticized PVAc particles in PVA water solution. Systems with full range of PVAc volume fraction φPVAc were studied. Kinetic relationships of several parameters which characterize film formation in drying process were compared and scrutinized. It revealed that the main factor which restrains coalescence of PVAc particles in the composite is high viscosity of PVA water solution at the final stage of composite structure formation. In tensile deformation conditions PVA/PVAc systems behave as being PVA matrix composites in a whole range of PVAc content. Use of Kerner approach, based on the self-consistency idea, for the analysis of ECOMP (φPVAc ) relation, confirms the continuity of PVA matrix.