Rapid Synthesis of Chemically Recyclable Polycarbonates from Renewable Feedstocks

Abstract

We report the rapid, one-pot synthesis of functional polycarbonates derived from renewable alcohols (i.e., glucose tetraacetate, acetyl isosorbide, lauryl alcohol, and ethanol) and a cyclic carbonate bearing an imidazolecarboxylate. This tandem functionalization/ring-opening polymerization strategy can be performed on multigram scale and eliminates the need for rigorous purification and specialized equipment. A wide range of glass transition temperatures (T g) was accessible from these renewable pendant groups (>75 °C T g window). We also synthesized several statistical copolycarbonates to show the thermal properties can be tailored with this tandem method. Additionally, we demonstrate a circular polymer economy via chemical recycling to a cyclic carbonate precursor. This work may facilitate development of sustainable polycarbonates with tailored properties that work toward eliminating plastic waste streams.

Chemically recyclable thermoplastics from reversible-deactivation polymerization of cyclic acetals

“…Polymers derived from moderately strained heterocyclic monomers are viable candidates for CRM because of their moderate ceiling temperatures (T c < 250°C), the temperature at which the change in Gibbs free energy (DG) = 0 for polymerizations where both the change in enthalpy (DH) and the change in entropy (DS) are negative (19). To date, polyesters (20)(21)(22)(23)(24)(25), polycarbonates (26)(27)(28)(29), and polymers derived from other heterocyclic monomers (30)(31)(32)(33)(34)(35) are capable of CRM. Several of these systems exhibit noteworthy properties.…”

Biobased High-Performance Aromatic–Aliphatic Polyesters with Complete Recyclability

“…Plastic production has grown substantially over the past several decades. Massive consumption of nonrenewable fossil resources and the accumulation of plastic wastes have caused severe environmental problems. − Developing chemically recyclable polymers that allow for recovery of the starting monomers via depolymerization is an attractive strategy to address the urgent issues of plastic sustainability. − Recently, important advances have been made for chemical recycling to monomers in polyesters, − polythioesters, − polycarbonates, − polyphthalaldehydes, , polyacetals, and poly­(cyclic olefins). , Among these recyclable polymers, polyesters are promising candidates owing to their renewable resources and excellent biodegradability. , One significant breakthrough made by Chen’s research group manifested the feasibility of ring-opening polymerization (ROP) of γ-butyrolactone and subsequent recyclability to its monomer . Continuing efforts have focused on improving the polymerizability of monomers and the thermal and mechanical performance of polymers without compromising their recyclability. − However, current research is mainly involved in aliphatic polyesters, which have some intrinsic limitations of material properties.…”

Regioregular Polymers from Biobased (R)-1,3-Butylene Carbonate

“…Furthermore, compared to the racemic compound and S -enantiomer, polymers from biobased R - BC exhibit greater crystalline properties, adding an advantage for using the bio-based feedstock. The semicrystalline properties of regioregular R -PBC are comparable to other common polyesters, such as poly­(ε-caprolactone) (PCL; T m = 63 °C) ,,, and poly­(β-propiolactone) ( T m = 79 °C) but with the added benefits of the polycarbonate molecular structure, such as chemical recycling by depolymerization or decomposition to neutral byproducts. ,− Attempts were made in this work to perform chemical recycling of the polymer to the monomer via depolymerization and distillation using P 2 - t -Bu as a catalyst; however, this resulted in low yields from the polymer starting mass (∼30%; Figures S34–S37). Depolymerization and sublimation of the polymer to the monomer yielded similar results (Figure S36).…”