Maximum Crystal Growth Rate and Its Corresponding State in Polymeric Materials

Abstract

The temperature dependence of crystal growth rate (G) shows a bell shape with the maximum growth rate G max. The activation energy for the molecular transport in G could be expressed in terms of equation of either Arrhenius or WLF. The G max showed remarkable molecular weight dependence. The plots of G/G max against T/T cmax showed a single master curve without molecular weight dependence. The ratio of G o/G max gave a constant value for each polymer. Plots of ln(G/G max)/ ln(G o/G max) against T/T cmax for various polymers showed the universal curve. The molecular weight dependence of G max was expressed as G max α MW α, α was a constant but depending on the morphological features on the crystallization. The value of α was a function of the adsorption mechanism of polymer molecules on the crystal growth front and its diffusion mechanism. The ratio of T cmax/T o m was formulated. T cmax was also correlated to many other thermodynamic transition temperatures.