KINETICS OF GROWTH OF DEVELOPING SPHERULITES

A model containing two rate constants is presented for the development of spherulites from sheaves. One, G//R, is a radial spherulite growth constant while the other, G//S, describes the rate of increase of apex angle of the sheaf. On the basis of this model, Avrami kinetics are developed which predict a change in the Avrami constant n from 5 to 3 as the sheaf develops into a spherulite. Hv light-scattering patterns are calculated according to this model and are found to compare favorably with those found during the early stages of the crystallization of polyethylene terephthalate.