Temperature dependence polymer crystal growth

The changes in the rate are a consequence of the change in balance between free energy of the melt and that of the solid and its influence on the nucleation processes. The LH theory has been used extensively to analyse polymer crystal growth data and is able qualitatively to describe processes that occur in a number of polymer systems. Its success lies in its ability to describe the temperature dependence of both the initial crystal thickness (L ) and the linear growth rate (coj.). A large volume of data has been shown to fit the relationship ... 

Reid et al. [ 1.12] described the effect of 1 % addition certain polymers on the heterogeneous nucleation rate at-18 °C the rate was 30 times greater than in distilled, microfiltered water and at -15 °C, the factor was still 10 fold hogher. All added polymers (1 %) influenced the nucleation rate in a more or less temperature-dependent manner. However, the authors could not identify a connection between the polymer structure and nucleation rate. None the less it became clear that the growth of dendritic ice crystals depended on to factors (i) the concentration of the solution (5 % to 30 % sucrose) and (ii) the rate at which the phase boundary water - ice crystals moved. However, the growth was found to be independent of the freezing rate. (Note of the author the freezing rate influences the boundary rate). 

Fig. 7 Temperature dependence of growth rate G of 010 faces of single crystals and Gr of spherulites for five low molecular weight fractions and a polymer of PEO (from [18] by permission of John Wiley Sons)...

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