Abstract
Biodegradable plastic films have been prepared by the crosslink reaction of dried gelatin films containing glycerol with formaldehyde vapor. Effects of the glycerol content on the physical and chemical properties and the biodegradability of the films were studied. As the glycerol content increased, the films became softer and more flexible, the elongation rate and the water vapor absorptivity increased, and the mechanical strength and the denaturation temperature decreased. The glycerol functioned as an osmotic medium of formaldehyde vapor for the effective crosslink formation inside the films, while the water-solubility of the films increased with increase in the glycerol content, since the rapid dissolution of the glycerol caused the coarsening of the films. Therefore, that the biodegradability of the films depends on both the glycerol content and the crosslink reaction time.
