Effects of Al2O3 and BaO nano-additives on mechanical characteristics of high-density polyethylene

Fabrication of polymer doped with metal oxides has been recently aimed to improve the physical, chemical, structural, morphological, thermal and mechanical characteristics. Therefore, the current study is directed to dope two nano-metal oxides into high density polyethylene (HDPE) using the roll-mixing and thermal-pressing techniques. The weight fractions of nanofillers were varied from 2.0% to 8.0% in the resulting composite. The FT-IR along with XRD and SEM were used to examine the structural properties of the new nanocomposites. Images from the scanning-electron microscopy demonstrated that Al₂O₃ and BaO nanoparticles were properly dispersed in the HDPE's polymeric material without essential aggregations. TGA as well as DSC were used to test the effects of Al₂O₃-NPs and BaO-NPs incorporation on the thermal properties of HDPE. Tensile tests were carried out to detect how the mechanical behavior of the polymeric matrix was affected by the weight fraction of the nanofiller. Elastic modulus, tensile strain (extension) at yield (%), tensile stress at break, ultimate tensile strength, tensile strain (extension) at break (%), and yield stress were determined in this research. It was concluded that the elastic modulus was found to increase with increasing the nanofiller content up to 4.0 wt% for BaO-NPs and 6.0 wt% for Al₂O₃-NPs to reach 229% and 208% increment, respectively with respect to the hosting matrix. The values of tensile stress at break, yield stress, tensile strain (extension) at break and tensile strain (extension) at yield of the synthesized nanocomposites decreased, as the content of both fillers increased from 2.0 to 8.0 wt%. Finally, a comparison between BaO-NPs and Al₂O₃-NPs, when added to the HDPE matrix, showed that the BaO nanofiller led to distinct improvements in the mechanical parameters of HDPE than Al₂O₃-NPs, for the same weight percentage.