The effect of reserved shish content on the structural evolution of high-entanglement ultrahigh molecular weight polyethylene films during the hot stretching process

To explore novel approaches facilitating the structural evolution of high-entanglement ultrahigh molecular weight polyethylene (UHMWPE) films, this study precisely controlled the temperature during compression molding to successfully prepare high-entanglement UHMWPE films with different shish contents. Using in-situ small-angle X-ray scattering (SAXS)/ultra-small-angle X-ray scattering (USAXS)/wide-angle X-ray diffraction (WAXD) alongside ex-situ scanning electron microscopy (SEM) and differential scanning calorimetry (DSC), we investigated the influence of shish contents on the structural evolution of high-entanglement UHMWPE films during hot stretching. The results indicate that increasing shish content in high-entanglement UHMWPE films reduces the accumulation of inclined lamellar crystals caused by high entanglement, promoting the transformation of inclined lamellar crystals into shish-kebab crystals and facilitating the formation of more shish-kebab crystals. In high-entanglement UHMWPE films with high shish content, eventually, all inclined lamellar crystals even transform into shish-kebab crystals. Reserving more shish crystals in high-entanglement UHMWPE films accelerates the rate of structural evolution, and eventually, all inclined lamellar crystals transform into shish-kebab crystals during stretching. [Display omitted] •High-entanglement UHMWPE films with different shish contents are successfully prepared by controlling the molding temperature.•The shish crystals are conducive to reducing the accumulation of inclined lamellar crystals caused by high entanglement.•As the shish content increases in the film, the rate of structural evolution during stretching is constantly accelerated.•The films with high shish content eventually all transform into shish-kebab crystals.