Preparation and Characterization of Gelatin/Chitosan/Carbodiimide Films

Abstract

In prior studies, we examined the effects of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and waterdispersiblepolycarbodiimides (pCDIs) on the properties of gelsproduced from gelatin and a gelatin/chitosan blend that may besuitable for a role in leather processing. Those studies showedmajor differences in gel properties as a function of the specificcarbodiimide. In this continuing study, the gelable productsformed from gelatin or a gelatin/chitosan blend modified withEDC or pCDIs were cast into films. The mechanical properties,hydrothermal stability, solubility, and water absorptivity of thefilms were examined. The range of values for mechanicalproperties (tensile strength, % elongation at break, Young’smodulus, and toughness) was small enough that it would likelynot be a major consideration in the choice of carbodiimide for aparticular application. Neither EDC nor the pCDIs at theconcentrations tested in this work had any discernible effect onthe hydrothermal stability of gelatin or gelatin/chitosan films.The effects of the pCDIs on solubility and water absorptionproperties of the films trended more closely with theconcentration of the pCDI than did the effects of EDC. Thispreliminary study explores the potential for using theenvironmentally friendly, water-dispersible pCDIs in gelatin andgelatin/chitosan-based films for use in leather coating orpackaging applications.