Development and Characterization of Genipin Cross-linked Gelatin Based Composites Incorporated with Vegetable-tanned Collagen Fiber (VCF)

Collagen fibers obtained from solid fibrous wastes generated in tannery have a high potential of being used in developing green composites. Earlier studies in our laboratory demonstrate that nonwoven composites can be derived from collagen fiber network using paper-making technology. The purpose of this work was to fabricate green composites based on gelatin and vegetable-tanned collagen fibers (VCF), using a non-toxic and naturally occurring compound, genipin, as cross-linking agent. VCF were obtained from split hide that has been tanned with vegetable tannins by mechanical milling technique. The VCF content in the networks of gelatin was varied from 10 to 40% (w/w) in dry weight relative to that of the gelatin. The structure, mechanical properties, thermal properties and water resistance of the composite films have been investigated with Fourier transform infrared spectroscopy (FTIR), mechanical testing, thermogravimetric analysis and swelling measurement. The results from those studies revealed that VCF and gelatin could mix with each other homogeneously under alkaline condition and the mechanical properties of the composite films at wet state were improved significantly over that of pure gelatin film. In addition, the composite films showed higher water resistance and thermal resistance than the control. FTIR analysis confirmed the molecular interactions between gelatin and VCF and the formation of cross-links between primary amino groups on gelatin and VCF. Our results indicated that VCF can be used as environmentally friendly and cost-effective potential reinforcing agent for green composites, providing better properties than the original biopolymer matrix. The genipin cross-linked gelatin/VCF composite film can be a promising candidate for the biomedical and packaging applications.