Controlled Ring-Opening Polymerization of Xylose-derived Lactones towards Sustainable Polyesters

Abstract

Utilizing bio-resources to construct sustainable polymers offers a highly promising solution to address the global plastic waste crisis. Herein, a series of seven-membered biorenewable lactones were synthesized from D-/L-xyloses as starting materials via a straightforward and effective four-step synthetic route, including selective Appel reaction, nucleophilic substitution reaction, saponification and subsequent cyclization. Furthermore, the well-controlled ring-opening polymerization (ROP) of these obtained biolactones was achieved under mild reaction conditions to obtain the desired polyesters with predictable molecular weights and narrow dispersities. The resultant polyesters exhibit excellent thermal properties with glass transition temperature (Tg) of up to 94.4 oC, which can be elevated by oxidizing the sulfur atoms within their backbone structure, thus further increasing the Tg value to 162 oC. Impressively, linear and star-shaped polyether polyols-initiated ROP facilitated the synthesis of amphiphilic block poly(ether-ester)s. Additionally, the resultant polyesters can be depolymerized back to pristine monomers via hydrolysis into hydroxyl acids and subsequent lactonization, enabling a closed-loop life cycle.