Model for the shape of polymer spherulites formed in a temperature gradient

A model is presented to account for the spherulitic morphology obtained during the oriented crystallization of a polymer in a moving temperature gradient. The model considers the sample to be divided into a series of narrow isothermal regions and, using an analogy to Snell’s law, correctly predicts the observed fibrillar curvature. Computer simulation of the proposed model yields spherulitic shapes that are consistent with the experimental results. A mechanism is proposed to account for the shapes observed, and the factors which affect them are discussed.