Synthesis of Telechelic Isotactic Polypropylenes for Circular Polypropylene-like Materials via Chain Transfer Polymerization
Zong-Lun Yu, Xing‐Wang Han, Peizhi Li, Yanan Zhao, Xun Zhang, Xiu‐Li Sun, Yanshan Gao, You‐Yun Zhou, Yong Tang
Abstract
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 i PP ( t PP) with sufficient difunctional purity for polycondensation has been limiting the development of circular polypropylenes with i 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 t 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 i PPs with i PP-like structure and thermomechanical properties and PE/ i PP multiblock copolymers were synthesized by the resulting t PPs.