Morphology and mechanical properties of crystalline polymers. III. Deformation of spherulites in polyethylene

The behavior of individual spherulites on uniform deformation of bulk polyethylene is studied with a model consisting of a spherical spherulite and a homogeneous matrix having the properties of the polymer. On the basis of this model, the nonaffine or inhomogeneous deformation in the spherulite is found to be primarily due to the curvilinearly anisotropic property or, more specifically, the spherically isotropic property of the spherulite. In the case of uniaxial stretching, mechanical interactions between spherulites are also to some extent responsible for the microinhomogeneous deformation. Details of the predicted deformation mode are compared with experimental observations reported in the literature and reasonable agreement is attained between theory and experiment for lightly drawn samples.