Thermal properties of low molecular weight poly(ethylene glycol) (PEG) were measured by a differential thermal analysis (DTA) apparatus specially designed for applying high voltage electric fields. The effect of electric fields on crystallization of PEG at a cooling rate of 3.3°C/min was examined after keeping at 80°C for various time intervals. Thermal history effects were discussed in terms of the concentration of residual predetermined nuclei present in the system at the start of crystallization by a modified Ziabicki's theory. It was found that the relaxation time of the process of cluster formation decreased up to 8,000 volt/cm and then increased at 10,000 volt/cm of field strength. The memory effect of the electric fields applied during the melting and crystallization processes was also found after remelting without the electric fields. The isothermal crystallization of low molecular weight PEG was also studied under high voltages by quenching the samples after prolonged times. The results suggested that the thickening and thinning via sliding diffusion in the crystals were facilitated by applying the electric field.
|Number of pages||9|
|Journal||Korea Polymer Journal|
|State||Published - 1998 Dec 1|