Pyrolysis of isotactic polypropylene as a route to telechelic oligomers and their functionalization

The increasing accumulation of plastic waste highlights the need for strategies able to convert post-consumer plastics into higher value materials. In this context, this work aims to valorize isotactic polypropylene (iPP), a widely used polyolefin that is often difficult to recycle, by converting it into functional telechelic oligomers. The approach is based on controlled thermal degradation of high molecular weight polypropylene followed by chemical functionalization. Controlled pyrolysis of isotactic polypropylene led to the formation of low molecular weight α,ω-divinylidene polypropylene oligomers (iPP-TVD). The obtained oligomers were characterized by ¹H NMR, SEC and DSC, confirming the formation of terminal double bonds, the reduction of molecular weight and the influence of degradation conditions on the crystallinity of the materials. The terminal double bonds were subsequently functionalized to introduce polar groups at the chain ends. Two strategies were investigated: hydrobromination followed by nucleophilic substitution, and thiol-ene radical addition. Overall, the results demonstrate that controlled pyrolysis combined with suitable functionalization strategies represents a promising route for the chemical valorization of polypropylene waste.