Influence of thermal and mechanical histories on the viscoelastic behavior of drawn polyethylene

Abstract

Abstract Storage and loss elasticity complex moduli E ′ and E ″ and temperatures at which the α relaxation takes place are studied with respect to thermal history, deformation speed, and molecular weight distribution of drawn linear polyethylene. Maximum values of E ′ and E ″ increase with draw ratio of the hot‐drawn samples, and the α relaxation temperatures increase by around 10°C when the polyethylene filaments are annealed at 110°C. The activation energy of the process, considered as a single one because the symmetrical shape of the maxima, increases with draw ratio, and this increase is less pronounced when the filaments are annealed. Annealing of the filaments produces a decrease in their E ′ values, but this decrease is almost negligible for filaments obtained from polyethylene with a broad molecular weight distribution. The final crystallinity of the filaments drawn at room temperature and subsequently annealed is higher for the filaments obtained at lower drawing speed.