Thermal Decomposition Kinetics of Survived β-Cyclodextrin from an Inclusion Complex of β-Cyclodextrin with Clove Oil

A double extrapolation method was employed to determine the most probable mechanism for the thermal decomposition reaction of the survived beta-cyclodextrin (beta-CD) from the inclusion complex of beta-CD with clove oil. The activation energy (E-a) curve calculated by Flynn-Wall-Ozawa method was clearly divided into three stages for the thermal decomposition process of the survived, beta-CD. The nearly parallel linear relationship between first and last stages was assessed as an Avrami-Erofe' ev A 1.5 model. Furthermore, the platform in the second stage of the decomposition of the survived, beta-CD in which each point has approximately equivalent E-a was carefully investigated using the reaction order (n) method. A regular decline in n as the temperature increased implied a complicated decomposition reaction mechanism for the survived beta-CD in this stage. Infrared spectroscopic profiles from the thermal decomposition of free, beta-CD and survived beta-CD were also compared. The changes in IR spectra below 1000 cm(-1) between free, beta-CD and survived beta-CD in the decomposition process were quite different which agreed with the calculated E-a values.