Compounded polypropylene powders with various concentrations of corn starch were processed in a Haake torque rheometer at constant temperature, 180 ยฐC, for different times in a closed system. A scanning electron micrograph of 5-min processed sample shows a ยฎne dispersion of starch particles in the polypropylene (PP) matrix. A good distribution and interaction of the starch particles are seen with increasing processing time (up to 15 min). Infrared spectroscopy evidence on the extracted ยฎlms shows that most interactions between PP and starch are obtained after about 10 min processing. The presence of 2ยฑ6 wt% starch in the PP has a melt-stabilising effect by reducing melt ยฏow index and increasing apparent viscosity with a good correlation. However, 6 wt% starch gives complete inhibition of the PP melt degradation up to 20 min processing. Carbonyl groups are not formed during processing of PP containing 6 wt% starch. This is also an indication of a starch stabilising effect on the PP chemical structure. An increase in elongation at break of PP ยฎlms having 6 wt% starch, when compared with the controls, is observed, while their ultimate tensile strength remains almost the same.