PLA/functionalized‐gum arabic based bionanocomposite films for high gas barrier applications

The present work focuses on the microwave synthesis of lactic acid‐grafted‐gum arabic (LA‐g‐GA) by polycondensation reaction and its influence as an additive to improve the gas barrier properties of poly(lactic acid) (PLA) films, prepared by solution casting method. It is observed that during the synthesis of LA‐g‐GA, hydrophilic gum is converted into hydrophobic due to grafting of in situ grown hydrophobic oligo‐(lactic acid). Subsequently, PLA/LA‐g‐GA bionanocomposite films are fabricated and characterized for structural, thermal, mechanical and gas barrier properties. Path breaking reduction in oxygen permeability (OP) of ～10 folds is achieved in case of PLA films containing LA‐g‐GA as filler. However, water vapor transmission rate (WVTR) is reduced up to 27% after 5 wt % addition of filler. Reduction in OP of this order of magnitude enables the PLA to compete with PET in term of enhancing shelf life and maintaining the food quality. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43458.