Towards Truly Sustainable Polymers: A Metal‐Free Recyclable Polyester from Biorenewable Non‐Strained γ‐Butyrolactone

Abstract

The first effective organopolymerization of the biorenewable "non-polymerizable" γ-butyrolactone (γ-BL) to a high-molecular-weight metal-free recyclable polyester is reported. The superbase tert-Bu-P4 is found to directly initiate this polymerization through deprotonation of γ-BL to generate reactive enolate species. When combined with a suitable alcohol, the tert-Bu-P4 -based system rapidly converts γ-BL into polyesters with high monomer conversions (up to 90 %), high molecular weights (Mn up to 26.7 kg mol(-1) ), and complete recyclability (quantitative γ-BL recovery).