Preparation of Porous Cellulose Packaging Films in Alcohol Coagulation

The barrier properties of the cellulose packaging films are current concerns for the fields of fruits and vegetables fresh-keeping packaging. One such porous films commonly used the pore formers as hole-forming materials whereas the compatibility and dispersity were not better with the cellulose solutions. In this study, the porous cellulose packaging films were prepared with natural broad-leaved pulp and LiCl/DMAc with different types of coagulation baths. The effects of methanol, ethanol, isopropanol, LiCl/DMAc and deionized water coagulation baths on the physical structures, oxygen and water vapor permeabilities and mechanical properties of the films were measured. Based on the scanning electron microscpy (SEM) observation, the cross section was loose when used the alcohol coagulations, especially the films with ethanol coagulation showed dactylopores. It was also found that the oxygen permeability had obviously improving with the effect of ethanol, which compared with water vapor permeability of the films. The porous cellulose packaging films had better mechanical properties and up to 12.7MPa which would satisfy the usage in packaging.