Understanding the Growth Rates of Polymer Cocrystallization in the Binary Mixtures of Different Chain Lengths: Revisited

摘要

Polymers often contain a polydispersity of chain lengths, which brings a complicated influence on crystallization behaviors. In our previous publication (J. Phys. Chem. B 2008, 112, 7370), we reported dynamic Monte Carlo simulations of cocrystallization in the binary mixtures of long (32-mer) and short (16-mer) homologue chains. We observed a linear dependence of crystal growth rates on the volume fractions of the long-chain component at low temperatures. In this article, with new confirming data, we further observed that the mole fractions also give linear dependence to the crystal growth rates, but split into two regimes. We attributed the phenomenon of two regimes to the variation between two thicknesses of lamellar crystals. The small thickness in the regime of low mole fractions is dominated by the metastable integer-number folding of 16-mers, which causes the "self-poisoning" effect on the crystal growth rates.