Kinetics studies on the thermal dissociation of the inclusion complex of beta-cyclodextrin with cinnamic aldehyde

The stability of the inclusion complex of beta-CD with cinnamic aldehyde was investigated by means of TG and DSC. The mass loss takes place in three stages: dehydration occurs at 50-120 degrees C; dissociation of beta-CD . C9H8O proceeds in the range 200-260 degrees C; and decomposition of beta-CD begins at 280 degrees C. The kinetics of the dissociation of beta-CD . C9H8O was studied by means of thermogravimetry both at constant temperature and with linearly increasing temperature. The results demonstrate that the dissociation of beta-CD . C9H8O is dominated by a one-dimensional diffusion process. The activation energy E is 160 kJ mol(-1) and the pre-exponential factor A is 5.8 x 10(14) min(-1). Scanning electron microscope observations and the results of crystal structure analysis are in good agreement with those of thermogravimetry.