Inhomogeneity of the strain rate of polymer materials with different supramolecular structures

The characteristics of rate oscillations in submicron deformation increments in the course of creep under compression of polymer materials of different classes, namely, amorphous poly(vinyl butyral), amorphous-crystalline poly(tetrafluoroethylene), and a composite consisting of polyimide with graphite particles, have been investigated. The strain rate has been measured using an interferometer on a deformation base of 300 nm. The periods of rate oscillations have been used to determine the deformation jumps, and the amplitude of rate oscillations has been used to determine the jump sharpness. It has been demonstrated that the radical differences in the structure of materials manifest themselves in the parameters of deformation jumps at different stages of creep. The type of jumps makes it possible to reveal the type of molecular packing in the starting polymer or the packing formed during deformation.