Mono- and multimolecular nucleation in polymer crystallization

Abstract

General relations for the nucleation rates are obtained with allowance for the contribution of the change of free energy in nucleation by two mechanisms — monomolecular, with the formation of folded nuclei, and multimolecular, i.e., nucleation with straightened polymer chains. It is shown that for flexible coiled molecules the formation of folded nuclei is more probable. However, as the degree of coiling decreases, whatever the reasons for the uncoiling of the macromolecules, the relative probability of formation of multimolecular nuclei increases, and at a certain critical value of the chain-folding parameter β=h/L the situation is reversed.