Development of novel biodegradable water chestnut starch/PVA composite film. Evaluation of plasticizer effect over physical, barrier, and mechanical properties

Abstract

A novel starch source from water chestnut (WCS) was used to develop composite film with polyvinyl alcohol (PVA) and different plasticizer's effects on functional properties were investigated. Results showed that the plasticizer decreased the swelling capacity but conversely increased the film solubility. The tensile strength (TS) of WCS-PVA film improved when incorporating plasticizer but gradually reduced at higher plasticizer concentration. The TS reached the maximum value of 28.82 and 17.14 MPa with sorbitol and glycerol, respectively, at 20% concentration. Conversely, elongation at break was decreased first and then increased with concentration. The water vapor permeability was observed to be slightly increased from 1.698 × 10−10 to 1.744 × 10−10 g Pa−1 m−1 s−1 for G-plasticized films and 1.124 × 10−10 to 1.134 × 10−10 g Pa−1 m−1 s−1 for S-plasticized films. Also, the result indicated that the incorporation of plasticizers enhanced biodegradability and made them suitable for food packaging without any hazardous effects. Novelty impact statement In previous work, starch-based films with polyvinyl alcohol (PVA) were prepared from different starch sources. However, no study has been reported so far on biocomposite film made from water chestnut with PVA. This paper was reported for the first time for the development of WCS-PVA biocomposite film and demonstrated the different plasticizer effects on its physical, barrier, and mechanical properties.