Recyclable and malleable thermosets enabled by activating dormant dynamic linkages

Nature Chemistry, Год журнала: 2022, Номер 14(12), С. 1399 - 1404

Опубликована: Сен. 26, 2022

Язык: Английский

---

Chemical recycling technologies for PVC waste and PVC-containing plastic waste: A review

Waste Management, Год журнала: 2023, Номер 166, С. 245 - 258

Опубликована: Май 16, 2023

Язык: Английский

---

Chemically circular, mechanically tough, and melt-processable polyhydroxyalkanoates

Science, Год журнала: 2023, Номер 380(6640), С. 64 - 69

Опубликована: Апрель 6, 2023

Polyhydroxyalkanoates (PHAs) have attracted increasing interest as sustainable plastics because of their biorenewability and biodegradability in the ambient environment. However, current semicrystalline PHAs face three long-standing challenges to broad commercial implementation application: lack melt processability, mechanical brittleness, unrealized recyclability, last which is essential for achieving a circular economy. Here we report synthetic PHA platform that addresses origin thermal instability by eliminating α-hydrogens repeat units thus precluding facile cis-elimination during degradation. This simple α,α-disubstitution enhances stability so substantially become melt-processable. Synergistically, this structural modification also endows with toughness, intrinsic crystallinity, closed-loop chemical recyclability.

Язык: Английский

---

A circular polyester platform based on simple gem-disubstituted valerolactones

Nature Chemistry, Год журнала: 2022, Номер 15(2), С. 278 - 285

Опубликована: Ноя. 7, 2022

Язык: Английский

---

Hydrogen‐Bonding Affords Sustainable Plastics with Ultrahigh Robustness and Water‐Assisted Arbitrarily Shape Engineering

Advanced Materials, Год журнала: 2022, Номер 34(19)

Опубликована: Март 9, 2022

Herein, the supramolecular plastic-like hydrogel (SPH) is introduced as a platform to fabricate sustainable plastics with ultrahigh stiffness and strength well water-assisted arbitrarily shapeable capability. The transparent are constructed from SPHs of cellulose ether/polycarboxylic acid complexes demonstrate mechanical robustness Young's modulus up 3.4 GPa tensile 124.0 MPa, superior or comparable most common plastics. Meanwhile, shape can be reversibly engineered by air drying diverse 2D/3D shapes structures, which generated conveniently via origami, kirigami, embossing, etc., in virtue plastic deformation memory effect SPHs. On basis multi-dimensional infrared-spectral analysis, it revealed that dense acid-acid acid-ether hydrogen (H)-bonding network responsible for while evolution water-polymer H-bonds into polymer-polymer during contributes fixing. This work provides novel method manufacturing simultaneous strong performance convenient processibility hydrogels behavior.

Язык: Английский

---

Closed-loop chemical recycling of cross-linked polymeric materials based on reversible amidation chemistry

Nature Communications, Год журнала: 2022, Номер 13(1)

Опубликована: Дек. 9, 2022

Abstract Closed-loop chemical recycling provides a solution to the end-of-use problem of synthetic polymers. However, it remains major challenge design dynamic bonds, capable effective bonding and reversible cleaving, for preparing chemically recyclable cross-linked Herein, we report maleic acid tertiary amide bond based upon amidation reaction between anhydrides secondary amines. This allows construction polymer networks with tailorable robust mechanical properties, covering strong elastomers tensile strength 22.3 MPa rigid plastics yield 38.3 MPa. Impressively, these polymeric materials can be completely depolymerized in an acidic aqueous at ambient temperature, leading efficient monomer recovery >94% separation yields. Meanwhile, recovered monomers used remanufacture without losing their original performance. work unveils general approach tunable performance closed-loop recyclability, which will open new avenue sustainable materials.

Язык: Английский

---

Rapid and Controlled Polymerization of Bio‐sourced δ‐Caprolactone toward Fully Recyclable Polyesters and Thermoplastic Elastomers

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(16)

Опубликована: Фев. 12, 2022

The development of chemically recyclable polymers presents the most appealing solution to address plastics' end-of-use problem. Despite recent advancements, it is highly desirable develop from commercially available monomers avoid costly and time-consuming commercialization. In this contribution, we achieve controlled ring-opening polymerization (ROP) bio-sourced δ-caprolactone (δCL) using strong base/urea binary catalysts. obtained PδCL capable chemical recycling δCL in an almost quantitative yield by thermolysis. Sequential ROP l-lactide (l-LA) affords well-defined PLLA-b-PδCL-b-PLLA triblock copolymers, which behave as thermoplastic elastomers with excellent elastic recovery, tensile strength ultimate elongation. upcycling recover ethyl lactate high yields achieved refluxing ethanol then distillation under reduced pressure.

Язык: Английский

---

Closing the “One Monomer–Two Polymers–One Monomer” Loop via Orthogonal (De)polymerization of a Lactone/Olefin Hybrid

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(5), С. 2264 - 2275

Опубликована: Янв. 27, 2022

Two well-known low-ceiling-temperature (LCT) monomers, γ-butyrolactone (γ-BL) toward ring-opening polymerization (ROP) to polyester and cyclohexene metathesis (ROMP) poly(cyclic olefin), are notoriously "nonpolymerizable". Here we present a strategy render not only polymerizability of both the γ-BL sites, orthogonally, but also complete orthogonal depolymerization, through creating an LCT/LCT hybrid, bicyclic lactone/olefin (BiL=). This hybrid monomer undergoes between ROP ROMP, depending on catalyst employed, affording two totally different classes polymeric materials from this single monomer: P(BiL=)ROP via functionalized olefin) P(BiL=)ROMP ROMP. Intriguingly, thermally robust chemically recyclable under mild conditions (25–40 °C), in presence catalyst, recover cleanly same chain unzipping scission, respectively. In ROP, topological stereochemical controls have been achieved structures characterized. Furthermore, intact functional group during (i.e., double bond lactone ROMP) is utilized for postfunctionalization tuning materials' thermal mechanical performances. The impressive depolymerization orthogonality further endows selective ROP/ROMP copolymer physical blend composites into starting monomer.

Язык: Английский

---

Tough while Recyclable Plastics Enabled by Monothiodilactone Monomers

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(3), С. 1877 - 1885

Опубликована: Янв. 3, 2023

The current scale of plastics production and the attendant waste disposal issues represent an underexplored opportunity for chemically recyclable polymers. Typical polymers are subject to trade-off between monomer's polymerizability polymer's depolymerizability as well insufficient performance practical applications. Herein, we demonstrate that a single atom oxygen-by-sulfur substitution relatively highly strained dilactone is effective robust strategy converting "non-recyclable" polyester into polymer by lowering ring strain energy in monomer (from 16.0 kcal mol-1 9.1 monothiodilactone). These monothio-modification monomers enable both high/selective recyclability, otherwise conflicting features typical monomer, evidenced regioselective ring-opening, minimal transthioesterifications, quantitative recovery pristine monomer. Computational experimental studies n→π* interaction adjacent ester thioester backbone has been implicated high selectivity propagation over transthioesterification. resulting demonstrates with its mechanical properties being comparable some commodity polyolefins. Thio-modification powerful enabling conversion six-membered dilactones tough thermoplastics exhibit promise next-generation sustainable

Язык: Английский

---

Understanding the Structure–Polymerization Thermodynamics Relationships of Fused-Ring Cyclooctenes for Developing Chemically Recyclable Polymers

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(2), С. 928 - 934

Опубликована: Янв. 5, 2022

Polymers that can be chemically recycled to their constituent monomers offer a promising solution address the challenges in plastics sustainability through circular use of materials. The design and development for next-generation recyclable polymers require an understanding relationships between structure monomers/polymers thermodynamics polymerization/depolymerization. Here we investigate structure–polymerization series cyclooctene contain additional ring fused at 5,6-positions, including trans-cyclobutane, trans-cyclopentane, trans-five-membered cyclic acetals. four- five-membered rings trans-fused reduce strain energies monomer, enthalpy changes polymerizations are found range −2.1 −3.3 kcal mol–1. Despite narrow changes, ceiling temperatures 1.0 M span from 330 680 °C, due low entropy ranging −2.7 −5.0 cal mol–1 K–1. Importantly, geminal substituents on acetal cyclooctenes temperature by ∼300 although they not directly attached cyclooctene. remote gem-disubstituent effect demonstrated here leveraged promote depolymerization corresponding tune thermomechanical properties.

Язык: Английский

---