The effect of a nucleating agent on lamellar growth in melt-crystallizing polyethylene oxide

TL;DR

This study investigates how a nucleating agent influences lamellar thickness and nucleation rate in melt-crystallizing polyethylene oxide, revealing that the agent results in thinner lamellae due to decreased surface tension.

Contribution

It provides quantitative analysis of the nucleating agent's effect on lamellar growth and introduces a lattice model to interpret the mechanism involved.

Findings

Nucleated samples have thinner lamellae than pure samples.

Lamellar thickness decreases with nucleating agent presence.

Results align with growth rate data from calorimetry.

Abstract

The effects of a (non co-crystallizing) nucleating agent on secondary nucleation rate and final lamellar thickness in isothermally melt-crystallizing polyethylene oxide are considered. SAXS reveals that lamellae formed in nucleated samples are thinner than in the pure samples crystallized at the same undercoolings. These results are in quantitative agreement with growth rate data obtained by calorimetry, and are interpreted as the effect of a local decrease of the basal surface tension, determined mainly by the nucleant molecules diffused out of the regions being about to crystallize. Quantitative agreement with a simple lattice model allows for some interpretation of the mechanism.