Formation and characterization of formaldehyde-crosslinked gelatin film

Some biodegradable plastics using gelatin have been prepared by the crosslink reaction of dried gelatin film with formaldehyde vapor. Effects of the reaction time on the physical properties and the biodegradability of the plastics were studied. With increasing the reaction time, the crosslink reaction proceeded from surface to inside and the water-solubility of the plastics was suppressed. The results suggest that the biodegradability can be controlled by regulating the reaction time. The physical properties depended on the humidity of the film rather than on the formation of crosslinkage.