Thermal creep of polyethylene in the presence of thermal cycling

The temperature-time dependence of Poisson's ratio and the volume relaxation of LDP is investigated in the case of uniaxial tension. It is established that at elevated temperatures and loads the material becomes denser and Poisson's ratio exceeds 0.5. It is shown that the (t) curves and the temperature dependence of the instantaneous Poisson's ratio are nonmonotonic, while the nature of the (t) relaxation changes qualitatively as a certain temperature region is entered and the stress is increased.Mekhanika Polimerov, Vol. 4, No. 3, pp. 421–427, 1968