Molecular mobility phenomena in oriented semicrystalline polymers. Electron paramagnetic resonance and mechanical analyses

Abstract

The drawing of semicrystalline polymers induces a wide structural rearrangement that affects the organization of the crystalline component and the properties of the amorphous phase. In particular, drawing strongly reduces mobility in the amorphous phase, and this is expected to play a role in the glass transition that is directly connected with mobility in the amorphous component. In agreement with this picture, the elastic modulus data and the electron paramagnetic resonance spectra indicate indirectly that T g increases on increasing the degree of drawing. This effect depends quantitatively on differences in the degree of drawability of the various samples.