Synthesis of high thermal stability Polypropylene copolymers with pyrrole functionality

Functionalization of polyolefins has been proven to be a promising way to fine-tune their properties, among which, improved thermal stability is crucial for high performance in end-use applications. However, it still remains in academia, as some important issues still need to be resolved for this methodology to move towards industrial scale-up, the most important of them being the development of one-step processes. This work focuses specifically on the development of a single-step functionalization route for the synthesis of high thermal and thermo-oxidative stability polypropylenes. The synthesis of Polypropylene (PP) bearing N-alkyl groups by copolymerization via metallocene catalysis is studied. The copolymers are found to exhibit high thermo-oxidative stability, whose origin appears to be based, not only on the radical scavenging activity of N-alkyl moieties, but also on the associated crosslinking that takes place under processing conditions. Some exploratory results from a solid-state 13 CNMR analysis provide support to a radical mechanism, involving coupling between benzyl-like pyrrolyl species. • A single-step process for the preparation of self-crosslinkable Polypropylene. • Preparation of high thermal stability Polypropylene by processing. • Polypropylene-based materials with oxidation temperatures up to 80ºC higher than the homopolymer.