Mechanical and oxygen barrier properties of LDPE/MMT/MAPE and LDPE/MMT/EVA nanocomposite films: A comparison study

Abstract

Enhanced mechanical and barrier properties are of special interest in food packaging industries, in which uniform dispersion of nanoparticles in polymers confers considerable improvement in these properties. In this study, maleic anhydride grafted polyethylene (MAPE) and ethylene vinyl acetate (EVA) compatibilised low density polyethylene/montmorillonite (LDPE/MMT) nanocomposite films were prepared with different concentrations of the compatibilisers by melt mixing technique. The delamination of MMT layers was evidenced from X-ray diffraction results that suggested an increase in the interlayer distance with the addition of compatibilisers, where MAPE is the better compatibiliser in delaminating MMT platelets in LDPE/MMT nanocomposites compared to EVA. The mechanical and barrier properties of compatibilised LDPE/MMT nanocomposites were better than uncompatibilised nanocomposites. The best improvement in tensile strength, tear strength and oxygen barrier were observed for LDPE/MMT/MAPE nanocomposites. However, the best improvements in elongation at break were seen for the LDPE/MMT nanocomposites compatibilised with EVA. Conclusively, MAPE compatibiliser is more effective in delaminating MMT platelets in LDPE/MMT nanocomposites, enhancing the mechanical and barrier properties of the nanocomposites. Results revealed that the optimum content of MAPE in terms of mechanical and barrier properties is 3 phc. The enhanced tensile and barrier properties of LDPE/MMT films with the incorporation of MAPE suggest a great potential of these nanocomposite films in food packaging.