A comparative study of different crosslinking agent-modified chitosan/corn cob biocomposite films

Abstract

The effect of corn cob (CC) content and crosslinking agent on tensile, morphological, thermal properties, gel fraction and enzymatic degradation of chitosan (CS)/corn cob (CC) biocomposite films was studied. Epichlorohydrin (EP) and adipic acid (ADP) as crosslinking agents were added to improve the properties of CS/CC biocomposite films. The addition of CC decreased the tensile strength and elongation at break, but increased the modulus of elasticity of CS/CC biocomposite films. The EP-modified CS/CC exhibited higher tensile and thermal properties than ADP-modified CS/CC. The formation of crosslinkages between CS and EP or CS and ADP was proven by Fourier transform infrared studies. The modified CS/CC biocomposite films with ADP and EP, respectively, showed better interface interaction, as demonstrated in scanning microscopy electron. Furthermore, the incorporation of CC in CS increased the weight loss of enzymatic degradation of biocomposite films. Moreover, EP-modified CS/CC shows better resistance to hydrolysis in α-amylase enzymatic degradation than ADP-modified CS/CC. The gel fraction of CS/CC biocomposite films increases with the increasing CC content, whereas the gel fraction of modified CS/CC with EP is higher compared to modified CS/CC with ADP. The novelty of our research showed that the modified biocomposite films with EP have the highest tensile and thermal properties, also gel content than others biocomposite films. The biocomposite films modified with ADP confer plasticization effect compared to unmodified and other modified biocomposite films.