Correlation between chain microstructure and activation energy in the pyrolysis of a high molecular weight isotactic polypropylene

The obtained results allows correlating the earliest low Eact values with the vanishing of chemical defective structures like carbonyls, as well as with the scission of some very few regular C-C bonds. The growing trend of the Eact, found from low to advanced pyrolysis stages, is associated to the collapse of the molecular weight and the decreasing of the isotacticity degree. The evolution towards shorter and more flexible chains is thought to underlie an increasingly energy demanding scission process.