Temperature effects for isothermal polymer crystallization kinetics

Abstract

We adopt the cluster size distribution model to investigate the effect of temperature on homogeneous nucleation and crystal growth for isothermal polymer crystallization. The model includes the temperature effects of interfacial energy, nucleation rate, growth and dissociation rate coefficients, and equilibrium solubility. The time dependencies of polymer concentration, number and size of crystals, and crystallinity (in Avrami plots) are presented for different temperatures. The denucleation (Ostwald ripening effect) is also investigated by comparing moment and numerical solutions of the population balance equations. Agreement between the model results and temperature-sensitive experimental measurements for different polymer systems required strong temperature dependence for the crystal-melt interfacial energy.

Crystallization Behaviors of Poly(3-hydroxybutyrate) and Poly(l-lactic acid) in Their Immiscible and Miscible Blends

“…Tashiro et al had observed the Avrami values of n = 5 for crystallization of syndiotactic polystyrene and suggested a three-dimensional conelike spherulite growth as a potential explanation for the large value of n . These phenomena have also been modeled with a distribution kinetics approach by Yang et al , In the present study, it is not sure what is the practical growth mode for such a high Avrami value. However, it is noticed that PLLA crystallizes from the mixed melt of PHB and PLLA, while PHB crystallizes in a phase-separated system, where PLLA exists as a solid crystallization phase.…”

Nonisothermal crystallization behavior of melt‐intercalated polyethylene‐clay nanocomposites

“…Also, the study of nonisothermal crystallization in polymer composites is of greater practical significance because processing techniques always involve nonisothermal conditions. Recently, the nonisothermal crystallization kinetics of various polymers was investigated theoretically and experimentally 27–33. Some models were proposed to quantitatively describe the crystallization kinetics 29–31.…”

“…Recently, the nonisothermal crystallization kinetics of various polymers was investigated theoretically and experimentally 27–33. Some models were proposed to quantitatively describe the crystallization kinetics 29–31. In general, the surface of filler particles acts as a nucleation site for semicrystalline polymer, thereby altering the amount or type of crystals.…”

In Situ Studies of Phase Separation and Crystallization Directed by Marangoni Instabilities During Spin‐Coating

“…It is apparent that the rate of crystallization remains unaffected by these changes in concentration (as shown in Table S2, Supporting Information), which is consistent with isothermal crystallization. [ 23 ] We attribute these changes in the onset of crystallization with concentration to the differences in fi lm thinning, with the spontaneous development of crystal nuclei only occurring when the polymer concentration becomes suffi ciently high within the fi lm.…”