Effect of maleic anhydride grafted polyethylene on engineering properties and morphology of fumed silica filled polyethylene blown films

Abstract

Blown films of high-density polyethylene (HDPE)/fumed silica (FS) composites were prepared by melt-mixing in twin-screw extruder. Maleic anhydride grafted polyethylene (PE-g-MA) was introduced to improve the state of filler dispersion during melt processing. The blown films were tested for thermal, mechanical, morphological, barrier, and optical properties. The Fourier Transform Infrared Spectroscopy-Attenuated Total Reflectance (FTIR-ATR) study indicated that interaction between FS and HDPE was slightly enhanced by PE-g-MA. No change in percent crystallinity was observed but mechanical properties improved after modification. Morphological analyses showed large FS clusters at higher loading which decreased after modification. Both oxygen and water vapor transmission rates of the films increased in composites as compared to HDPE, plausibly due to formation of nanogaps in blown film and/or increased solubility of penetrant molecules at filler–matrix interface.