Title
Effects of drying conditions on polyvinyl alcohol–water and cellulose acetate–tetrahydrofuran films
Authors
IONUT OVIDIU FORTU CIPRIAN NEGOESCU and IOAN MAMALIGA

Received January 7, 2019
Published Volume 53 Issue 5-6 May-June
Keywords polyvinyl alcohol, cellulose acetate, films, drying behavior

Abstract
Polymer films and membranes play an important role in modern industries that use paints and varnishes, magnetic tapes, CDs, adhesives, foil stickers, pharmaceutical patches, solar cells, wastewater treatment etc. The properties of these films and membranes depend strongly on the drying conditions, including thermodynamic equilibrium, diffusion coefficients, thermal agent temperature and velocity. This paper presents the effects of temperature and air velocity on the drying of polyvinyl alcohol and cellulose acetate films.
The drying studies were carried out on two systems: polyvinyl alcohol-water and cellulose acetate-tetrahydrofuran, aiming to highlight the influence of temperature and velocity of the drying gas on the polymer films. Unlike the polyvinyl alcohol films, which, after drying, have a compact structure, the cellulose acetate films have a porous structure, with pores of approximately 1 micrometer diameter.1 This difference in structure was also evidenced by the different profiles of the drying curves of the solutions obtained by dissolving the two polymers in water and tetrahydrofuran, respectively.