Synthesis of Telechelic Isotactic Polypropylenes for Circular Polypropylene-like Materials Via Chain Transfer Polymerization

While synthesizing circular polymers with telechelic polyolefin building blocks recently emerged as a promising strategy for addressing conventional polyethylenes' sustainability challenges, the lack of telechelic PP (PP) with sufficient difunctional purity for polycondensation has been limiting the development of circular polypropylenes with PP-like structures and properties. Here we described a combined approach of coordinative chain transfer polymerization and transition-metal-catalyzed quenching reaction with various acyl chlorides, affording PPs with a high difunctional ratio (up to ∼99%) and broad end functional group scope. The steric effect of polymeryl-Zn species and the role of Pd catalyst were revealed by DFT. This method also solved the low difunctional ratio challenge for telechelic polyethylenes. Ester-linked PPs with PP-like structure and thermomechanical properties and PE/PP multiblock copolymers were synthesized by the resulting PPs.