Polymeric films prepared from starch and a crosslinker extracted from avocado seeds

Abstract

The avocado seeds, considered as waste, were used for the extraction of oil rich in pentosans and starch. The avocado starch (AS) and a commercial starch (CS) are then used for the formation of polymeric films by casting. Avocado oil (AO, as natural crosslinker) and ethylene glycol (EG) are utilized as crosslinkers to modify the properties of the films. All polymeric structures are characterized by physical inspection, FTIR, TGA-DSC, and water-insoluble fraction. The results indicate that the incorporation of AO and EG augments the thermal stability by decreasing the degradation rates compared to that of the unmodified AS and CS polymeric films. In addition, the degradation temperature of the polymeric films is modified by the addition of crosslinkers. The degradation temperature of AS, AS-AO, AS-EG, were 300, 286, and 306 C, accordingly, whereas those for CS films are 314, 314.5, and 307.7 C for CS, CS-AO, and CS-EG, respectively. Our study demonstrates that natural wastes could be useful and increase the profits of the avocado processing industries.