A Study of the Relationship between the Rate of Return Strain of Polytetrafluoroethylene on Time, Mechanical Stress and Dose of Electron Irradiation

Abstract

The paper is devoted to the study of the influence of factors on the rate of return deformation of polytetrafluoroethylene. The dependence of the rate of return strain (ε'r) on time (t), the dose of electron irradiation (D) and mechanical stress (σ) in thin films of polytetrafluoroethylene has been experimentally investigated. Significant variations of ε'r have been found dependingon on t, D and σ. A decrease in the rate of return deformation during irradiation of the material is associated with the frictional properties between macromolecules and a change in the structure, which leads to a weaker straightening of the polymer and their poor sliding. The resulting curves for both unirradiated and irradiated material are satisfactorily described in the exponential and linear models. For dependencies ε'r on D, these are decreasing functions, and for ε'r on σ, these are increasing functions.