Upcycling of Poly(ϵ‐caprolactone) to Valuable Chemicals by TBD‐Catalyzed Efficient Methanolysis Strategy

Abstract

As a petroleum-derived polyester material, poly(ɛcaprolactone) (PCL) plays an essential role in biomedical field due to its excellent biocompatibility and non-toxicity. With the increasing use of PCL in recent years, its waste disposal has become a significant challenge. To address this challenge, we demonstrate a high-efficiency organocatalysis strategy for the chemical upcycling of PCL to valuable chemical. Among organocatalysts explored in this article, 1,5,7triazabicyclo[4,4,0]dec-5-ene (TBD) shows superior perform-ance for transforming end-of-life poly(ɛ-caprolactone) into highly value-added methyl 6-hydroxyhexanoate with quantitative conversion in a short time. The endwise unzipping depolymerization mechanism is corroborated by monitoring molecular weight during depolymerization process and 1 H NMR control experiments. Furthermore, this approach is also practicable for large-scale depolymerization for commercial PCL plastics, providing idea for promoting the sustainable development of PCL plastics.

Preparation of Block Copolymers by a Sequential Transesterification Strategy: A Feasible Route for Upcycling End-of-Life Polyester Plastics to Elastomers

“…In the previous reports by our group and others, 1,5,7-triazabicyclo­[4,4,0]­dec-5-ene (TBD) was evidenced to be an excellent catalyst for transesterification. − Herein, a synthetic route of the PLA/PCL block copolymer via a TBD-mediated sequential transesterification reaction with the participation of diols was designed (Scheme ). The study on the feasibility of the transesterification of PCL to obtain macromolecular initiators (HO-PCL-OH) with hydroxyl groups in both terminal ends was carried out first.…”

Triazabicyclodecene: A versatile catalyst for polymer synthesis

“…To address this concern, Wang and Xu explored catalytic depolymerization of PCL, with TBD demonstrating promising capabilities. 294 Remarkably, even at low catalyst loadings of 0.2 mol% in excess methanol, TBD achieved complete depolymerization of PCL to methyl 6-hydroxyhexanoate within just 3 h at 80 C. Mechanistic investigations indicated a bifunctional activation mechanism prevailing over a nucleophilic pathway. Chen and colleagues also evaluated TBD's potential in the depolymerization of poly(γ-BL).…”

“…Although PCL boasts relatively facile biodegradation compared to other plastics, complete degradation still spans several years, potentially leading to issues such as microplastics. To address this concern, Wang and Xu explored catalytic depolymerization of PCL, with TBD demonstrating promising capabilities 294 . Remarkably, even at low catalyst loadings of 0.2 mol% in excess methanol, TBD achieved complete depolymerization of PCL to methyl 6‐hydroxyhexanoate within just 3 h at 80 °C.…”

Ultrafast and selective recycling of poly(p-dioxanone) to monomers by using Brønsted–Lewis acidic ionic liquids as solvents/catalysts

“…8 (A) Energy economy factor, (B) environmental factor, and (C) environmental energy impact factor of poly(cyclic esters) depolymerization. 20,22,26,[32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47] (10.9 °C min) is better than in all of the related works (Fig. 8C).…”