Kinetic study on dissociation of amylose/salicylic acid compound using non-isothermal method

The inclusion compound of amylose and salicylic acid (SA) was prepared by a sealed temperature control method, and the formation of the inclusion compound was confirmed by IR spectrum and powder X-ray diffraction.  The kinetic parameters of dissociation of amylose/SA compound were studied by the non-         isothermal method which was defined as a relationship between the dissociation ratio and time.  The values of activation energy (E_a) and frequency factors (lnA) were calculated by a nonlinear least-square method.  In this study, the formation of the inclusion compound of amylose / SA was confirmed by IR spectrum powder X-ray diffraction.  SA existed in a molecule form in the spiral stouction of amylose.  The dissociation of amylose/SA compound was attributed to first order reaction.  The values of E_a calculated by the nor-isothermal method were 21.71 and 22.41 kJ·mol⁻¹ at heating rate 5 and 10 ℃·h⁻¹, respectively.  The corresponding isothermal method value of E_a was 22.17 kJ·mol⁻¹; the calculated lnA values were 9.32 and 10.08 at heating rate 5 and 10 ℃·h⁻¹,  respectively.  The corresponding isothermal method lnA value was 9.26.  The results were in good agreement with E_a values and lnA values by isothermal method.  These results indicated that the non-isothermal method described in this study could be adequately used for the stability study of inclusion compound and was a rapid and accurate method for the determination of kinetic parameters.