An investigation of the effects of organomodified-fluoromica on mechanical and barrier properties of compatibilized high density polyethylene nanocomposite films

Nanocomposite sheets based on high density polyethylene and containing organically modified fluoromica and three different compatibilizers (ethylene vinyl acetate copolymer and two maleic anhydride grafted high density polyethylene (HDPE-g-MA) grades with different melt flow indices) were prepared by melt mixing processing in an internal mixer. In order to evaluate the direct relationship between different properties of compression molded sheets and their microstructures, mechanical and barrier properties of the final nanocomposites were examined. Fluoromica content, compatibilizer type, and compatibilizer to clay ratio were changed to study the effects of different material variables on the final nanocomposite properties. A second-order polynomial function fitted well on experimental results and showed that the compatibilizer molecular weight played an important role in the morphology and consequently, the nanocomposite properties. Reducing the compatibilizer molecular weight resulted in better delamination and subsequent enhancement in mechanical and barrier properties. Optimization of various properties was done over the 16 designed experiments and 42% improvement in Young's modulus and 30% reduction of permeability, compared to pristine high density polyethylene, were obtained for the optimal sample.