The nucleation in oligomer melts

Abstract

Impulse NMR has been used to study the crystallization conditions of oligoethylene- and oligo-butylene adipates as a function of the melt temperature at constant crystallization temperature. Residual crystal structures have been found in the melts above the melting temperature; these act as nuclei in the subsequent crystallization. The Avrami equation describing the crystallization kinetics from the melt has been modified on the basis of this result; in addition to the classical and homogeneous nucleation there is one in which the crystal nuclei are the residual crystal structures already existing in the melt. © 1978