Starch-recycled gelatin composite films produced by extrusion: Physical and mechanical properties

This article describes using recycled gelatin in production of blends of starch (Manihot esculenta Crantz). Films were produced by extrusion using varying percentages of recycled gelatin (2.5, 5, 7.5, 10, 12.5, and 15% relative to the starch weight), plasticized with glycerol (20 wt % relative to the starch weight), and then characterized. The morphology results showed films with a cohesive matrix and no phase separation. The crystallinity analysis showed that the extrusion process eliminated crystalline zones of the granules and produced low-crystallinity films. The addition of recycled gelatin caused an increased thermal stability and significantly increased the mechanical strength and solubility in water of the films. It also accelerated the biodegradation process. It was concluded that the process of recycling and reprocessing did not affect the properties of gelatin, even as it has significantly influenced the properties of the films. (c) 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46254.