Evolution of microstructure in semi-crystalline polymers under large plastic deformation

Abstract The plastic properties of semi-crystalline polymers up to large strains are reviewed in terms of the particular mechanisms activated in these materials. Also, a specific point is made on the transformations affecting the microstructure under the effect of the deformation (density, viscoelastic response and macromolecular orientation). The case of orthorhombic polyethylene and poly(ether ether ketone) are investigated for the illustration of the general principles emphasizing crystalline defects. The constitutive plastic behaviour is determined by means of a novel technique. The microstructural evolution is modelled in terms of glide in the crystalline lamellae, the development of damage and the modelling of the amorphous chains in the interlamellar regions.