Dynamic thermogravimetric degradation of poly(3-hydroxybutyrate)/aliphatic-aromatic copolyester blends

The thermal degradation of poly(3-hydroxybutyrate)/aliphatic-aromatic copolyester (PHB/AAC) blends was investigated by the thermogravimetric method under dynamic conditions (50-650 °C) in an inert atmosphere. The characteristics of the TG curves were determined; some can be used as indicators of the thermal stability of the blend. Kinetic parameters (the apparent activation energy, Ea and pre-exponential factor, A) were calculated by the Flynn-Wall-Ozawa and Kissinger methods. It is observed that both Ea and A vary in blends. By using both methods approximately equal values of activation energy are obtained for the whole conversion range. There is no true compensation effect in the case of non-isothermal degradation of PHB/AAC blends.