Drying temperature dependence of adhesion via H-bonds between polyvinyl alcohol and cellulose films

Abstract

This study is to address the drying temperature dependence of the adhesion between an iodine-doped polyvinyl alcohol (PVA-Ix) and a saponified triacetyl cellulose (TAC) films, where a water-borne PVOH solution is used as an adhesive. Upon laminating three layers into a TAC/PVA-Ix/TAC sheet with two PVOH adhesive layers there between, drying process is carried out at temperature of 50, 60, 70, 80, and 90 °C, respectively. As a result, the adhesion (peel) strength initially increases with temperature, reaching a maximum at around 70 °C, and then decreases with further increasing temperature to 90 °C. We have interpreted this phenomenon by means of a physical model built to account for the competition between the kinetic and thermodynamic driving forces. In another words, there occurs competition in the drying process between the kinetic forces coupled with the water diffusion out of the system and the thermodynamic forces of the hydrogen-bond formation in the adhesion interfaces.