Manufacture of biaxially oriented high-density polyethylene membranes with tunable properties via “structuring” processing strategy

Abstract

Polyethylene (PE) is the most widely used thermoplastic resin in the world now. Among the endless number of PE products, films constitute over 50% of the consumer market and are applied in optical, packing and filtration areas according to distinct condensed structures. In this work, we prepared high-density polyethylene (HDPE)/liquid paraffin (LP) precursor films with various condensed structures by adjusting the LP content. Subsequently, we delved into the mechanism behind structural evolution during the uniaxial stretching process. Our findings reveal that an increase in LP content can increase the mobility of molecular chains, fostering the transformation of lamellae into an oriented microfiber structure during uniaxial stretching process. This improvement contributes to the enhanced stretchability of the films. Finally, we fabricated biaxially oriented membranes with distinct properties. These properties span from non-porous packaging films with exceptional optical characteristics to porous films suitable for specialized separation applications, achieved through the manipulation of the LP content. In summary, we manufacture different kinds of PE films through the strategy of “structure→ processing→ property”, which provides efficient access to design a given polymer material with desired structure and tunable properties via “structuring” processing.