MICROMECHANISM OF THE DEFORMATION PROCESS OF MACROMOLECULAR SYSTEMS

The mechanism of cold drawing is described by a model of inhomogeneous deformation. The fundamental assumption of the model is that a random polymer coil subjected to an external stress forms a highly oriented strand and a residual rest coil that remains isotropic after a phase o f elastic deformation. In this coil-strand transition model, the stran d is growing during deformation by reduction of the volume part of the rest coil. In the volume-creating model, the constant orientation dif ference between rest coil and strand gives rise to a linear energy and entropy law and thus to a constant tensile stress. In the volume-cons erving model, a decreasing power law for the stress-strain relationshi p is found, which is able to explain certain features of the cold draw ing process.