• Pyrolysis
• Polyolefins
• recycle of polyolefins
• Functional polyolefins
• Telechelic polyolefins
• Polypropylene

The purpose of this thesis was to prepare telechelic polypropylene, named α,ω-diisopropenyloligopropylene, by low temperature pyrolysis of isotactic high molecular weight polypropylene and performing functionalization reactions on the pyrolyzed, with the idea of using post-consumer recycled polypropylene (PCR) in the future as a starting material to obtain a high-value product from plastics waste.
The α,ω-diisopropenyloligopropylene could be used to synthetized tetrablock copolymers, for example with polyethylene to obtain compatibilizer for PE/PP blends. The functionalized products could find an application in fields like binders and adhesives. The product with the primary alcohol could find an application as macromonomer, if combined with a dicarboxylic acid, to synthesize a chemically recyclable ester-linked polypropylene.
The first point of interest was to perform batch pyrolysis and find the optimum to understand how residence time, temperature and pressure affect the number of double bonds, degree of crystallinity, and molecular weight of the telechelics.
Second, a preliminary study was conducted on a new continuous pyrolysis reactor provided by Sabic to understand whether the results obtained in batch were transferable to continuous for hypothetical future scale-up.
Following pyrolysis, functionalization reactions were performed on the telechelics to obtain polyolefins functionalized with polar groups.
The reactions used were epoxidation with meta-chloro peroxybenzoic acid (m-CPBA) followed by acid-catalysed epoxide ring-opening reaction, hydration reaction, and hydroboration reaction.
Several properties were studied: Gel permeation chromatography (GPC) was used to establish the molecular weight and polydispersity index, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) to understand the degradation temperature, degree of crystallinity and melting temperature. 1HNMR and ATR-IR to estimate the number of double bonds of the pyrolyzed product quantitatively and qualitatively, respectively. 1HNMR was also used to estimate the conversions of functionalization reactions. In addition, complex viscosity studies were conducted by rheology to assess whether the polar groups of the functionalized products create nests in the extremely apolar matrix of the polyolefins.
Finally, batch pyrolysis of some PCR plastics was performed and the product was functionalized with epoxy groups.