Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(24)
Опубликована: Апрель 9, 2024
In this paper, we proposed a heteroatom substitution strategy (HSS) in the δ-valerolactone (VL) system to modulate thermodynamics toward chemically recyclable polyesters. Three VL-based monomers containing different heteroatoms (M
Язык: Английский
Advanced Materials, Год журнала: 2022, Номер 35(7)
Опубликована: Ноя. 11, 2022
Development of closed-loop chemically recyclable plastics (CCRPs) that can be widely used in daily life a fundamental solution to the global plastic waste crisis. Hence, it is great significance develop easy-to-recycle CCRPs possess superior or comparable material properties commodity plastics. Here, novel dual crosslinked CCRP, namely, supramolecular covalent adaptable networks (supra-CANs), reported, which not only displays mechanical higher than strong and tough polycarbonate, but also exhibits excellent solvent resistance as thermosets. The supra-CANs are constructed by introducing reversible noncovalent crosslinks into dynamic polymer networks, resulting highly stiff thermosets exhibit thermoplastic-like ductile behaviors well reprocessability rehealability. In contrast, analogs do have (CANs) show elastomeric with significantly decreased strength. Importantly, developed CANs converted back initial monomers high yields purity at room temperature, even additives, enables sustainable polymer-monomer-polymer circulation. This work provides new design principles for high-performance polymers substitutes conventional
Язык: Английский
Процитировано
134
Chemical Reviews, Год журнала: 2024, Номер 124(5), С. 2617 - 2650
Опубликована: Фев. 22, 2024
The societal importance of plastics contrasts with the carelessness which they are disposed. Their superlative properties lead to economic and environmental efficiency, but linearity puts climate, human health, global ecosystems at risk. Recycling is fundamental transitioning this linear model into a more sustainable, circular economy. Among recycling technologies, chemical depolymerization offers route virgin quality recycled plastics, especially when valorizing complex waste streams poorly served by mechanical methods. However, exists in interlinked system end-of-life fates, complementarity each approach key environmental, economic, sustainability. This review explores recent progress made five commercial polymers: poly(ethylene terephthalate), polycarbonates, polyamides, aliphatic polyesters, polyurethanes. Attention paid not only catalytic technologies used enhance efficiencies also interrelationship other systemic constraints imposed Novel polymers, designed for depolymerization, concisely reviewed terms their underlying chemistry potential integration current plastic systems.
Язык: Английский
Процитировано
84
Macromolecules, Год журнала: 2023, Номер 56(3), С. 731 - 750
Опубликована: Фев. 6, 2023
A crucial modern dilemma relates to the ecological crisis created by excess plastic waste production. An emerging technology for reducing is production of "chemically recyclable" polymers. These polymers can be efficiently synthesized through ring-opening polymerization (ROP/ROMP) and later recycled pristine monomer ring-closing depolymerization, in an efficient circular-type system. This Perspective aims explore chemistry involved preparation these monomer/polymer systems, while also providing overview challenges involved, including future directions.
Язык: Английский
Процитировано
61
Journal of Polymer Science, Год журнала: 2023, Номер 61(17), С. 1937 - 1958
Опубликована: Май 19, 2023
Abstract Polyamides (PA) are a family of engineering thermoplastics used in wide range applications including automotive, building, construction, separation processes, textiles, and so forth. This is related to their good properties (mechanical thermal) which can also be modified by additives, other polymers (blends multilayers) fillers (composites). But these complex systems (several components) make the final materials more difficult recycle. In this review, basic statistics on production rate polyamides presented different recycling methods reported compare advantages limitations with respect economics technical analyses. The discussion includes biological, chemical, mechanical, physical, thermal treatments reintroduce, as much possible, parts after end‐of‐service. Finally, general conclusion current state PA several openings for future developments satisfy concept circular economy sustainability.
Язык: Английский
Процитировано
54
Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(26)
Опубликована: Апрель 27, 2023
Chemically recyclable, circular polymers continue to attract increasing attention, but rendering both catalysts for depolymerization and high-performance recyclable is a more sustainable yet challenging goal. Here we introduce dual catalyst/polymer recycling system in that inorganic phosphomolybdic acid catalyzes selective of high-ceiling-temperature biodegradable poly(δ-valerolactone) bulk phase, which, upon reaching suitable molecular weight, exhibits outstanding mechanical performance with high tensile strength ≈66.6 MPa, fracture strain ≈904 %, toughness ≈308 MJ m-3 , thus markedly outperforms commodity polyolefins, recovering its monomer pure state quantitative yield at only 100 °C. In sharp contrast, the uncatalyzed not requires temperature >310 °C also low yielding non-selective. Importantly, recovered can be repolymerized as reproduce same polymer, thereby closing loop, recycled catalyst reused repeatedly runs without loss catalytic activity efficiency.
Язык: Английский
Процитировано
49
Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(17)
Опубликована: Фев. 29, 2024
Abstract Geminal ( gem −) disubstitution in heterocyclic monomers is an effective strategy to enhance polymer chemical recyclability by lowering their ceiling temperatures. However, the effects of specific substitution patterns on monomer's reactivity and resulting polymer's properties are largely unexplored. Here we show that, systematically installing ‐dimethyl groups onto ϵ‐caprolactam (monomer nylon 6) from α ϵ positions, both redesigned lactam ‐nylon 6’s highly sensitive position, with ranging non‐polymerizable polymerizable inferior far superior parent 6. Remarkably, 6 ‐dimethyls substituted at γ position amorphous optically transparent, a higher T g (by 30 °C), yield stress 1.5 MPa), ductility 3×), lower depolymerization temperature 60 °C) than conventional
Язык: Английский
Процитировано
20
Recycling, Год журнала: 2024, Номер 9(3), С. 37 - 37
Опубликована: Май 6, 2024
This review article gathers the most recent recycling technologies for thermoset and thermoplastic polymers. Results about existing experimental procedures their effectiveness are presented. For polymers, focuses mainly on fibre-reinforced polymer composites, with an emphasis epoxy-based systems carbon/glass fibres as reinforcement, due to environmental concerns of end-of-life management. Thermal processes (fluidised bed, pyrolysis) chemical (different types solvolysis) discussed. The combined (microwave, steam, ultrasonic assisted techniques) extraordinary attempts (electrochemical, biological, ionic liquids) analysed. Mechanical that leads downgrading materials is excluded. Insights also given upcycling methodologies have been implemented until now reuse fibres. As state-of-the-art approach common matrices presented, together appropriate additivation matrix upcycling. Mechanical, chemical, enzymatic described, among others. use composites quite new, thus, achievements With all above information, this extensive can serve a guide educational purposes, targeting students technicians in polymers recycling.
Язык: Английский
Процитировано
19
Science China Chemistry, Год журнала: 2024, Номер 67(9), С. 2803 - 2841
Опубликована: Авг. 12, 2024
Язык: Английский
Процитировано
19
Angewandte Chemie International Edition, Год журнала: 2022, Номер 62(4)
Опубликована: Ноя. 28, 2022
Nylon-6 is selectively depolymerized to the parent monomer ϵ-caprolactam by readily accessible and commercially available lanthanide trisamido catalysts Ln(N(TMS)2 )3 (Ln=lanthanide). The depolymerization process solvent-free, near quantitative, highly selective, operates at lowest temperature reported date. catalytic activity of different trisamides scales with Ln3+ ionic radius, this effective post-consumer as well Nylon-6+polyethylene, polypropylene or polyethylene terephthalate mixtures. Experimental kinetic data theoretical (DFT) mechanistic analyses suggest initial deprotonation a Nylon terminal amido N-H bond, which covalently binds catalyst polymer, followed chain-end back-biting in units are sequentially extruded from chain end.
Язык: Английский
Процитировано
56
Macromolecules, Год журнала: 2022, Номер 55(10), С. 3860 - 3868
Опубликована: Май 12, 2022
It is highly desirable to develop chemically recyclable polymers address the challenge in establishing a sustainable circular polymer economy. Despite mass production and widespread applications, there are limited reported examples for polyurethanes capable of chemical recycling monomers with high efficiency purity. In this contribution, we report "living"/controlled ring-opening polymerization (ROP) bio-renewable δ-caprolactone (δCL) at room temperature bulk using an organobase combination urea as catalyst. The telechelic PδCL diol precursor well-defined terminal groups can be prepared catalyst loading low 0.05 mol %. A one-pot strategy by cascade ROP δCL step-growth precursors diisocyanate under solvent-free conditions produced thermoplastic polyurethane elastomers excellent elastic recovery, tensile strength, ultimate elongation, residue strain. Remarkably, recycled recover purity yield (∼99%) simple thermolysis.
Язык: Английский
Процитировано
52