Superior low-temperature mechanical toughness of the PP-based blown micro/nano layer films

Abstract

The poor low-temperature mechanical properties of polypropylene (PP) film strongly restrict its applications in low-temperature service conditions like frozen packaging, or cold countries and regions. Here the PP-based films including 8-, 128- and 512-layer, were successfully produced by the self-developed nanolayered blown film technology. The 128-layer film exhibited exceptionally enhancement in the low-temperature mechanical properties, outperforming the commercialized 2-layer film with increments of 389%, 141%, and 126% in tensile impact strength, elongation at break, and tear strength, respectively. The DSC, WAXD, and SAXS results disclosed that the crystalline structure of PP in different micro/nano layer films was nearly identical. So, the ultrathin micro/nano layer structure should be responsible for the robust low-temperature mechanical properties, which dissipated energy during the mechanical break by promoting the large plastic deformation. Briefly, the PP-based micro/nano layer films fabricated by the self-developed nanolayer blown film technology show robust low-temperature mechanical properties, so this work may attract some attention in the polymer film industry.