THE EFFECT OF INORGANIC ADDITIVES ON THE DECOMPOSITION OF POLY (BETA-HYDROXYBUTYRATE) INTO VOLATILE PRODUCTS

Inorganic oxides such as CaO, MgO, PbO, PbO2, Al2O3, ZnO and calcium h ydride destabilize PHB to an extent dependent on the basicity of the a dditive which leads to much easier formation of volatile products comp ared with PHB itself. Of the additives examined, attention has been fo cused on the reaction of MgO, which leads to significant formation of a considerably more stable product whose maximum rate of decomposition into volatiles is at 670 K (PHB itself decomposes with a maximum rate at 572 K). An interpretation based on the interaction of MgO with PHB end groups has been proposed.