Mechanical behavior of nanoperlite/nanoclay hybrid nanocomposites based on polyethylene: Experimental and numerical validation of hyperelastic models

This contribution concerns preparation and characterization of low-density polyethylene (LDPE) melt-mixed blends in the presence of organically-modified montmorillonite nanoclays and silane-modified nano perlite. Dispersion state of hybrid nanofillers was observed by scanning electron microscopy (SEM) technique. A significant increase in average roughness of fracture surface of polyethylene with addition of hybrid nanofillers and intensive ridges and valleys are observed in the samples. Crystallization and melting characteristics of LDPE nanocomposites reinforced by hybrid nanoclay/nanoperlite were studied by differential scanning calorimetry (DSC) in isothermal mode. Hybrid nanofiller incorporation increased crystallization and melting temperature which can be related to high interaction between polymeric chains and hybrid nanofillers. The results of mechanical investigation revealed that Young’s modulus and tensile strength of LDPE are improved with introduction of hybrid nanofiller. Six constitutive models, Yeoh, Arruda-Boyce, Mooney-Rivilen, polynomial, Van der Waals, and Odgen were applied to investigate the stress-strain behavior of LDPE/nano clay/nano perlite nanocomposites. It was concluded that the ability of these models to predict the true behavior of the nanocomposite samples directly depends on the amount of hybrid nanofiller. Results showed that Arruda-Boyce, Vander-Waals, Yeoh and Mooney-Rivlin models show more deviation from experimental data in all nanohybrid filler content, whereas the others, Ogden, polynomial (2), can be used for all samples.