Photocross‐linking of low‐density polyethylene. III. Supermolecular structure studied by SALS

The supermolecular structure of photocross‐linked polyethylene (XLPE) has been studied by small‐angle light scattering (SALS). The data show that the spherulitic structure of XLPE gradually deteriorates with increasing degree of cross‐linking and increasing irradiation temperature from well‐developed spherulites to rodlike aggregates and disordered lamellar structures. A photocross‐linked sample of PE has lower crystallinity, smaller crystallites, and smaller spherulites than does the original sample. At high degrees of cross‐linking, the SALS patterns show little or no spherulitic structure. Results with photocross‐linked polyethylene demonstrate that the overall effect of cross‐linking on the morphological structure is similar to that of an increase in molecular weight of the polymer.