THE THERMAL-DEGRADATION KINETICS OF DEXTRAN AND PULLULAN

The effect of molar mass and, in the case of dextran, of the degree of branching on the thermal degradation kinetics of dextran and pullulan was studied in the presence and absence of oxygen. Although the initi al mass loss of the dextran samples occurred at higher temperatures th an that of the pullulan samples, the overall thermal degradation activ ation energies were lower for dextran than for pullulan. In the case o f dextran the thermal stability was found to decrease with molar mass and degree of branching. The molar mass of pullulan, in the range of 1 0(4) to 10(5) g/mol, appeared to have no significant influence on the thermal characteristics of the samples.