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.