The thermal behaviour of aloe-emodin, chrysophanol and physcion and their kinetics have been investigated under non-isothermal conditions by means of differential thermal analysis （DTA） and thermogravimetry （TG）. ...The thermal behaviour of aloe-emodin, chrysophanol and physcion and their kinetics have been investigated under non-isothermal conditions by means of differential thermal analysis （DTA） and thermogravimetry （TG）. The thermal characteristics have been determined using the DTA and TG-DTG curves. The non-isothermal kinetic data were analyzed by means of the Achar method and the Madhusudanan-Krishnan-Ninan （MKN） method. The possible reaction mechanisms have been investigated by comparing the kinetic parameters. The kinetic equation for aloe-emodin, chrysophanol and physcion can be expressed as dα/dt=Aexp（-E/RT）1/3（1-α）[-In（1-α]2. The activation energy E （kJ mol^-1） of the three free anthraquinones are 78.09, 89.54, and 107.5 and their InA/s^-1 are 22.98, 36.85 and 43.60, respectively.展开更多
文摘The thermal behaviour of aloe-emodin, chrysophanol and physcion and their kinetics have been investigated under non-isothermal conditions by means of differential thermal analysis （DTA） and thermogravimetry （TG）. The thermal characteristics have been determined using the DTA and TG-DTG curves. The non-isothermal kinetic data were analyzed by means of the Achar method and the Madhusudanan-Krishnan-Ninan （MKN） method. The possible reaction mechanisms have been investigated by comparing the kinetic parameters. The kinetic equation for aloe-emodin, chrysophanol and physcion can be expressed as dα/dt=Aexp（-E/RT）1/3（1-α）[-In（1-α]2. The activation energy E （kJ mol^-1） of the three free anthraquinones are 78.09, 89.54, and 107.5 and their InA/s^-1 are 22.98, 36.85 and 43.60, respectively.
