Particularity of relaxation of mechanical properties of the kapton h type polyimide films at different strain rates after long-term exposure to environmental conditions

The influence of strain rate on mechanical properties under tensile conditions at room temperature of polyimide films of Kapton H type of different thicknesses in the initial state and after exposure for several years under normal conditions was investigated. It was found that at all strain rates, exposure leads to changes in the values ​​of elastic and forced elasticity moduli and deformation characteristics, the nature of which depends on the thickness and structure of the film. The nature of the speed sensitivity of highly elastic deformation components after exposure changes to the opposite. A change in the fracture characteristics of the samples of the exposed films was found.