a solution of polypropylene in xylene from its boiling point to room temperature xs is a measure of stereoregularity or isotacticity of the polypropylene the thermo oxidative stability of the polypropylene was determined by both oven aging and oxidative induction time oit measurements after compression molding the polypropylene into 10 mil thick specimens for oven aging these 2 inch u00d7 2 5 inch specimens were placed in a forced circulation hot air oven maintained at 150 u00b0 c the aging procedure followed the guidelines of astm d3012 the samples were inspected five days a week and failure was indicated by characteristic powdery disintegration and brittleness of the polypropylene for oit measurement about 5 mg of the compression molded sample was crimped in a difference scanning calorimeter perkin elmer model dsc 7 the sample was heated to the test temperature under nitrogen and then the nitrogen gas was replaced by oxygen from this time t 0 onward scanning was done in the time mode a tangent was drawn to the exothermic oxidation peak the intersection of this tangent with the initial baseline measured from t 0 gave the oxidative induction time or oit note that higher oven life or oit values indicate greater oxidative stability of the polymer the data in table ii show that the polypropylene produced in the reactor by the inventive method and good yield and stereoselectivity as indicated.