In this work, the solidification process and the crystal growth kinetics of
Polyethylene glycol 4000 (PEG4000) and polyethylene glycol 6000 (PEG6000)
(molecular average weight 4000 and 6000, respectively) were characterized b
y thermal optical microscopy (OM) and differential scanning calorimetry (DS
C). The growth rate decreased with increasing crystallization temperature.
The kinetic rate constant was lower for PEG6000 than for PEG4000 (29,300 an
d 32,900 K-2, respectively). This behavior is related to the different numb
er of folds (folding index n) of the crystal structures. From comparison of
microscopy and calorimetry measurements, the kinetic rate constant values
were higher by microscopy due to different melt histories, self-nucleation,
and degree of entanglement.