Preparation of high-density polyethylene/montmorillonite nanocomposites with high gas barrier by micro-nano torsional laminated extrusion

High-density polyethylene (HDPE) is a popular material for use in medical, packaging, and construction applications due to its low cost and good processing characteristics. Its chemical stability and resistance make it particularly suitable for use in storage tanks for chemicals and gases. However, its low gas barrier properties and limited strength have hindered its widespread use in such applications. This study puts forward a novel approach, micro-nano torsional laminated extrusion (MNTLE), for preparing HDPE/montmorillonite (MMT) nanocomposites with improved mechanical and gas barrier properties. The MNTLE method yields a more uniform of fillers in the composites, which leads to greater mechanical strength (a 46.18% increase in tensile strength and a 27.37% rise in elongation break), along with a higher crystallinity (a 16.27% increase) compared to compression molding. Moreover, the improved dispersion and orientation of the Nano-MMT in composites fabricated by MNTLE lead to a 41.9% reduction in oxygen permeability compared to press-molded composites. Consequently, this study introduces an innovative processing method that enhances the mechanical and gas barrier characteristics of the material, thus offering potential applications in the manufacturing of lining materials for Type IV hydrogen storage tanks.