Molecular weight dependence and stereoselective chain cleavage during the early stages of the isotactic polypropylene pyrolysis

The comparative study on the pyrolysis of two Polypropylene samples, with a similar high isotactic character but quite distinct molecular weights, reveals a significant difference in their thermal performances. The detailed qualitative analysis of the parameters, which are expected to govern the thermal degradation, leads to reasonably assume a main role of the molecular weight in their relative early stabilities. Furthermore, the correlation found between the sharp initial build-up of the E-act and the selective cleavage of isotactic stereosequences in both samples, suggests the relevance of the stereo regular length into the energy required for chain scission. (C) 2017 Elsevier Ltd. All rights reserved.