| Abstract: | Effects of high energy radiation on stress relaxation behavior of unoriented (λ=1) and oriented (λ=9) ultrahigh molecular weight polyethylene (UHMWPE) were investigated. As in a previous study, the stress relaxation is interpreted in terms of a model that consists of two thermally activated processes acting parallel. The first process is related to crystal and the second to the amorphous fraction. Application of the two-process model enabled separate studying of the influence of irradiation on viscoelastic behavior of these two fractions. |
