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Pu M, Fang C, Zhou X, Wang D, Lin Y, Lei W, Li L. Recent Advances in Environment-Friendly Polyurethanes from Polyols Recovered from the Recycling and Renewable Resources: A Review. Polymers (Basel) 2024; 16:1889. [PMID: 39000744 PMCID: PMC11244063 DOI: 10.3390/polym16131889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2024] [Revised: 06/25/2024] [Accepted: 06/27/2024] [Indexed: 07/17/2024] Open
Abstract
Polyurethane (PU) is among the most universal polymers and has been extensively applied in many fields, such as construction, machinery, furniture, clothing, textile, packaging and biomedicine. Traditionally, as the main starting materials for PU, polyols deeply depend on petroleum stock. From the perspective of recycling and environmental friendliness, advanced PU synthesis, using diversified resources as feedstocks, aims to develop versatile products with excellent properties to achieve the transformation from a fossil fuel-driven energy economy to renewable and sustainable ones. This review focuses on the recent development in the synthesis and modification of PU by extracting value-added monomers for polyols from waste polymers and natural bio-based polymers, such as the recycled waste polymers: polyethylene terephthalate (PET), PU and polycarbonate (PC); the biomaterials: vegetable oil, lignin, cashew nut shell liquid and plant straw; and biomacromolecules: polysaccharides and protein. To design these advanced polyurethane formulations, it is essential to understand the structure-property relationships of PU from recycling polyols. In a word, this bottom-up path provides a material recycling approach to PU design for printing and packaging, as well as biomedical, building and wearable electronics applications.
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Affiliation(s)
- Mengyuan Pu
- School of Mechanical and Precision Instrument Engineering, Xi’an University of Technology, Xi’an 710048, China; (M.P.); (D.W.)
- School of Printing, Packaging Engineering and Digital Media Technology, Xi’an University of Technology, Xi’an 710048, China; (Y.L.); (W.L.)
| | - Changqing Fang
- School of Mechanical and Precision Instrument Engineering, Xi’an University of Technology, Xi’an 710048, China; (M.P.); (D.W.)
- School of Printing, Packaging Engineering and Digital Media Technology, Xi’an University of Technology, Xi’an 710048, China; (Y.L.); (W.L.)
| | - Xing Zhou
- School of Mechanical and Precision Instrument Engineering, Xi’an University of Technology, Xi’an 710048, China; (M.P.); (D.W.)
- School of Printing, Packaging Engineering and Digital Media Technology, Xi’an University of Technology, Xi’an 710048, China; (Y.L.); (W.L.)
| | - Dong Wang
- School of Mechanical and Precision Instrument Engineering, Xi’an University of Technology, Xi’an 710048, China; (M.P.); (D.W.)
- School of Printing, Packaging Engineering and Digital Media Technology, Xi’an University of Technology, Xi’an 710048, China; (Y.L.); (W.L.)
| | - Yangyang Lin
- School of Printing, Packaging Engineering and Digital Media Technology, Xi’an University of Technology, Xi’an 710048, China; (Y.L.); (W.L.)
| | - Wanqing Lei
- School of Printing, Packaging Engineering and Digital Media Technology, Xi’an University of Technology, Xi’an 710048, China; (Y.L.); (W.L.)
| | - Lu Li
- Key Laboratory of Auxiliary Chemistry and Technology for Chemical Industry, Ministry of Education, Shaanxi University of Science and Technology, Xi’an 710021, China;
- Shaanxi Collaborative Innovation Center of Industrial Auxiliary Chemistry and Technology, Shaanxi University of Science and Technology, Xi’an 710021, China
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2
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O’Dea R, Nandi M, Kroll G, Arnold JR, Korley LTJ, Epps TH. Toward Circular Recycling of Polyurethanes: Depolymerization and Recovery of Isocyanates. JACS AU 2024; 4:1471-1479. [PMID: 38665666 PMCID: PMC11040557 DOI: 10.1021/jacsau.4c00013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 02/29/2024] [Accepted: 03/26/2024] [Indexed: 04/28/2024]
Abstract
We report a depolymerization strategy to nearly quantitatively regenerate isocyanates from thermoplastic and thermoset polyurethanes (PUs) and then resynthesize PUs using the recovered isocyanates. To date, chemical/advanced recycling of PUs has focused primarily on the recovery of polyols and diamines under comparatively harsh conditions (e.g., high pressure and temperature), and the recovery of isocyanates has been difficult. Our approach leverages an organoboron Lewis acid to depolymerize PUs directly to isocyanates under mild conditions (e.g., ∼80 °C in toluene) without the need for phosgene or other harsh reagents, and we show that both laboratory-synthesized and commercially sourced PUs can be depolymerized. Furthermore, we demonstrate the utility of the recovered isocyanate in the production of second-generation PUs with thermal properties and molecular weights similar to those of the virgin PUs. Overall, this route uniquely provides an opportunity for circularity in PU materials and can add significant value to end-of-life PU products.
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Affiliation(s)
- Robert
M. O’Dea
- Department
of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, United States
- Center
for Plastics Innovation, University of Delaware, Newark, Delaware 19716, United States
| | - Mridula Nandi
- Department
of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, United States
| | - Genevieve Kroll
- Department
of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, United States
| | - Jackie R. Arnold
- Department
of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, United States
| | - LaShanda T. J. Korley
- Department
of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, United States
- Center
for Plastics Innovation, University of Delaware, Newark, Delaware 19716, United States
- Department
of Materials Science and Engineering, University
of Delaware, Newark, Delaware 19716, United States
| | - Thomas H. Epps
- Department
of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, United States
- Center
for Plastics Innovation, University of Delaware, Newark, Delaware 19716, United States
- Department
of Materials Science and Engineering, University
of Delaware, Newark, Delaware 19716, United States
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3
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Horváth T, Kecskés K, Jordán Csábrádiné A, Szőri-Dorogházi E, Viskolcz B, Szőri M. Searching for the Achilles' Heel of Urethane Linkage-An Energetic Perspective. Polymers (Basel) 2024; 16:1126. [PMID: 38675045 PMCID: PMC11053941 DOI: 10.3390/polym16081126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 03/21/2024] [Accepted: 04/15/2024] [Indexed: 04/28/2024] Open
Abstract
A sudden increase in polyurethane (PU) production necessitates viable recycling methods for the waste generated. PU is one of the most important plastic materials with a wide range of applications; however, the stability of the urethane linkage is a major issue in chemical recycling. In this work, termination reactions of a model urethane molecule, namely methyl N-phenyl carbamate (MPCate), are investigated using G3MP2B3 composite quantum chemical method. Our main goal was to gain insights into the energetic profile of urethane bond termination and find an applicable chemical recycling method. Hydrogenation, hydrolysis, methanolysis, peroxidation, glycolysis, ammonolysis, reduction with methylamine and termination by dimethyl phosphite were explored in both gas and condensed phases. Out of these chemicals, degradation by H2, H2O2 and CH3NH2 revealed promising results with lower activation barriers and exergonic pathways, especially in water solvation. Implementing these effective PU recycling methods can also have significant economic benefits since the obtained products from the reactions are industrially relevant substances. For example, aniline and dimethyl carbonate could be reusable in polymer technologies serving as potential methods for circular economy. As further potential transformations, several ionizations of MPCate were also examined including electron capture and detachment, protonation/deprotonation and reaction with OH-. Alkaline digestion against the model urethane MPCate was found to be promising due to the relatively low activation energy. In an ideal case, the transformation of the urethane bond could be an enzymatic process; therefore, potential enzymes, such as lipoxygenase, were also considered for the catalysis of peroxidation, and lipases for methanolysis.
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Affiliation(s)
- Tamás Horváth
- Institute of Chemistry, University of Miskolc, Miskolc-Egyetemváros A/2, H-3515 Miskolc, Hungary; (K.K.); (A.J.C.); (E.S.-D.)
| | - Karina Kecskés
- Institute of Chemistry, University of Miskolc, Miskolc-Egyetemváros A/2, H-3515 Miskolc, Hungary; (K.K.); (A.J.C.); (E.S.-D.)
| | - Anikó Jordán Csábrádiné
- Institute of Chemistry, University of Miskolc, Miskolc-Egyetemváros A/2, H-3515 Miskolc, Hungary; (K.K.); (A.J.C.); (E.S.-D.)
| | - Emma Szőri-Dorogházi
- Institute of Chemistry, University of Miskolc, Miskolc-Egyetemváros A/2, H-3515 Miskolc, Hungary; (K.K.); (A.J.C.); (E.S.-D.)
| | - Béla Viskolcz
- Higher Education and Industrial Cooperation Centre, University of Miskolc, H-3515 Miskolc, Hungary;
| | - Milán Szőri
- Institute of Chemistry, University of Miskolc, Miskolc-Egyetemváros A/2, H-3515 Miskolc, Hungary; (K.K.); (A.J.C.); (E.S.-D.)
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4
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Liu B, Westman Z, Richardson K, Lim D, Stottlemyer AL, Farmer T, Gillis P, Hooshyar N, Vlcek V, Christopher P, Abu-Omar MM. Polyurethane Foam Chemical Recycling: Fast Acidolysis with Maleic Acid and Full Recovery of Polyol. ACS SUSTAINABLE CHEMISTRY & ENGINEERING 2024; 12:4435-4443. [PMID: 38516400 PMCID: PMC10952008 DOI: 10.1021/acssuschemeng.3c07040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 02/15/2024] [Accepted: 02/16/2024] [Indexed: 03/23/2024]
Abstract
Chemical recycling of polyurethane (PU) waste is essential to displace the need for virgin polyol production and enable sustainable PU production. Currently, less than 20% of PU waste is downcycled through rebinding to lower value products than the original PU. Chemical recycling of PU waste often requires significant input of materials like solvents and slow reaction rates. Here, we report the fast (<10 min) and solvent-free acidolysis of a model toluene diisocyanate (TDI)-based flexible polyurethane foam (PUF) at <200 °C using maleic acid (MA) with a recovery of recycled polyol (repolyol) in 95% isolated yield. After workup (hydrolysis of repolyl ester and separations), the repolyol exhibits favorable physical properties that are comparable to the virgin polyol; these include 54.1 mg KOH/g OH number and 624 cSt viscosity. Overall, 80% by weight of the input PUF is isolated into two clean-cut fractions containing the repolyol and toluene diamine (TDA). Finally, end-of-life (EOL) mattress PUF waste is recycled successfully with high recovery of repolyol using MA acidolysis. The solvent-free and fast acidolysis with MA demonstrated in this work with both model and EOL PUF provides a potential pathway for sustainable and closed-loop PU production.
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Affiliation(s)
- Baoyuan Liu
- Department
of Chemistry and Biochemistry, University
of California, Santa
Barbara, California 93106, United States
| | - Zach Westman
- Department
of Chemical Engineering, University of California, Santa Barbara, California 93106, United States
| | - Kelsey Richardson
- Department
of Chemical Engineering, University of California, Santa Barbara, California 93106, United States
| | - Dingyuan Lim
- Department
of Chemistry and Biochemistry, University
of California, Santa
Barbara, California 93106, United States
| | | | - Thomas Farmer
- The
Dow Chemical Company, Midland, Michigan 48640, United States
| | - Paul Gillis
- The
Dow Chemical Company, Midland, Michigan 48640, United States
| | - Nasim Hooshyar
- The
Dow Chemical Company, Herbert H Dowweg 5, Hoek 4542 NH,The Netherlands
| | - Vojtech Vlcek
- Department
of Chemistry and Biochemistry, University
of California, Santa
Barbara, California 93106, United States
| | - Phillip Christopher
- Department
of Chemical Engineering, University of California, Santa Barbara, California 93106, United States
| | - Mahdi M. Abu-Omar
- Department
of Chemistry and Biochemistry, University
of California, Santa
Barbara, California 93106, United States
- Department
of Chemical Engineering, University of California, Santa Barbara, California 93106, United States
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5
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Clark R, Shaver MP. Depolymerization within a Circular Plastics System. Chem Rev 2024; 124:2617-2650. [PMID: 38386877 PMCID: PMC10941197 DOI: 10.1021/acs.chemrev.3c00739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 01/18/2024] [Accepted: 02/08/2024] [Indexed: 02/24/2024]
Abstract
The societal importance of plastics contrasts with the carelessness with which they are disposed. Their superlative properties lead to economic and environmental efficiency, but the linearity of plastics puts the climate, human health, and global ecosystems at risk. Recycling is fundamental to transitioning this linear model into a more sustainable, circular economy. Among recycling technologies, chemical depolymerization offers a route to virgin quality recycled plastics, especially when valorizing complex waste streams poorly served by mechanical methods. However, chemical depolymerization exists in a complex and interlinked system of end-of-life fates, with the complementarity of each approach key to environmental, economic, and societal sustainability. This review explores the recent progress made into the depolymerization of five commercial polymers: poly(ethylene terephthalate), polycarbonates, polyamides, aliphatic polyesters, and polyurethanes. Attention is paid not only to the catalytic technologies used to enhance depolymerization efficiencies but also to the interrelationship with other recycling technologies and to the systemic constraints imposed by a global economy. Novel polymers, designed for chemical depolymerization, are also concisely reviewed in terms of their underlying chemistry and potential for integration with current plastic systems.
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Affiliation(s)
- Robbie
A. Clark
- Department
of Materials, School of Natural Sciences, University of Manchester, Manchester M13 9PL, United
Kingdom
- Sustainable
Materials Innovation Hub, Henry Royce Institute, University of Manchester, Manchester M13 9PL, United
Kingdom
| | - Michael P. Shaver
- Department
of Materials, School of Natural Sciences, University of Manchester, Manchester M13 9PL, United
Kingdom
- Sustainable
Materials Innovation Hub, Henry Royce Institute, University of Manchester, Manchester M13 9PL, United
Kingdom
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6
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Han Y, Jiang Y, Xu D, Shi S, Zhang Q, Zhang Y, Feng J, Tan L, Li K. Green preparation of antibacterial shape memory foam based on bamboo cellulose nanofibril and waterborne polyurethane for adaptive relief of plantar pressure. Int J Biol Macromol 2024; 256:128444. [PMID: 38035958 DOI: 10.1016/j.ijbiomac.2023.128444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 11/10/2023] [Accepted: 11/20/2023] [Indexed: 12/02/2023]
Abstract
This study developed an aqueous solution blending and freeze-drying method to prepare an antibacterial shape memory foam (WPPU/CNF) based on waterborne PHMG-polyurethane and cellulose nanofibers derived from bamboo in response to the increasing demand for environmentally friendly, energy conserving, and multifunctional foams. The obtained WPPU/CNF composite foam has a highly porous network structure with well-dispersed CNFs forming hydrogen bonds with the WPPU matrix, which results in a stable and rigid cell skeleton with enhanced mechanical properties (80 KPa) and anti-abrasion ability. The presence of guanidine in the polyurethane chain endowed the WPPU/CNF composite foam with an instinctive and sustained antibacterial ability against Escherichia coli and Staphylococcus aureus. The WPPU/CNF composite foam exhibited a water-sensitive shape memory function in a cyclic shape memory program because of the chemomechanical adaptability of the hydrogen-bonded network of CNFs in the elastomer matrix. The shape-fixation ratio for local compression reached 95 %, and the shape-recovery rate reached 100 %. This allows the WPPU/CNF pad prototype to reversibly adjust the undulation height to adapt to plantar ulcers, which can reduce the local plantar pressure by 60 %. This study provides an environmentally friendly strategy for cellulose-based composite fabrication and enriches the design and application of intelligent foam devices.
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Affiliation(s)
- Yanting Han
- West China Hospital, West China School of Nursing, Sichuan University, Chengdu, China
| | - Yuanzhang Jiang
- College of Biomass Science and Engineering, Key Laboratory of Biomass Fibers for Medical Care in Textile Industry, Sichuan University, Chengdu, China
| | - Dingfeng Xu
- Division of Glycoscience, Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, AlbaNova University Centre, Stockholm, Sweden
| | - Shuo Shi
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
| | - Qiang Zhang
- College of Biomass Science and Engineering, Key Laboratory of Biomass Fibers for Medical Care in Textile Industry, Sichuan University, Chengdu, China
| | - Yong Zhang
- College of Biomass Science and Engineering, Key Laboratory of Biomass Fibers for Medical Care in Textile Industry, Sichuan University, Chengdu, China
| | - Jinhua Feng
- West China Hospital, West China School of Nursing, Sichuan University, Chengdu, China
| | - Lin Tan
- College of Biomass Science and Engineering, Key Laboratory of Biomass Fibers for Medical Care in Textile Industry, Sichuan University, Chengdu, China; Sate Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, China.
| | - Ka Li
- West China Hospital, West China School of Nursing, Sichuan University, Chengdu, China.
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7
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Kim S, Li K, Alsbaiee A, Brutman JP, Dichtel WR. Circular Reprocessing of Thermoset Polyurethane Foams. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2305387. [PMID: 37548061 DOI: 10.1002/adma.202305387] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 07/28/2023] [Indexed: 08/08/2023]
Abstract
Thermoset polyurethane (PU) foams are widely used in industrial applications, but they cannot be recycled by conventional melt reprocessing because of their cross-linked structures. The introduction of carbamate exchange catalysts converts thermoset PU into covalent adaptable networks (CANs), which are amenable to reprocessing at elevated temperatures. However, this approach has produced solid PU films, which have fewer uses and lower commercial demand. In this work, simultaneous reprocessing and refoaming of thermoset PU foams is demonstrated by leveraging the melt-processability of PU CANs and allowing cell growth by gas generation in a twin-screw extruder. The optimal operating temperature of the refoaming process is determined through chemical, thermal, and structural analysis of PU foam extrudates. The foam-to-foam extrusion process produces controllable, continuous, and uniform foam structures, as characterized by cell diameter and cell number density. Low-density PU foams are obtained through a process simulating injection molding. The compression properties of reprocessed PU foam are compared with as-synthesized PU foam to demonstrate efficacy of the refoaming processes. These results demonstrate that PU foams can be prepared through recycling while maintaining microstructural and chemical integrity. In the future, this strategy may be applied to thermoset PU foams of various chemical compositions and shows promise for scalability.
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Affiliation(s)
- Subeen Kim
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA
| | - Kelvin Li
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA
| | - Alaaeddin Alsbaiee
- Polyurethane Systems Department, Performance Materials Division, BASF Corporation, 1609 Biddle Avenue, Wyandotte, MI, 48192, USA
| | - Jacob P Brutman
- Polyurethane Systems Department, Performance Materials Division, BASF Corporation, 1609 Biddle Avenue, Wyandotte, MI, 48192, USA
| | - William R Dichtel
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA
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8
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Lee S, Park Y, Baik Y, Kim JC, Lee Y, Choi M. Hierarchical LTL Zeolite as an Efficient and Sustainable Solid Acid Catalyst for Replacing HCl in the Production of Polyurethane Intermediates. Angew Chem Int Ed Engl 2023; 62:e202304244. [PMID: 37366041 DOI: 10.1002/anie.202304244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 06/26/2023] [Accepted: 06/27/2023] [Indexed: 06/28/2023]
Abstract
In many industrially important reactions, caustic mineral acid catalysts have been successfully replaced with green solid acids such as zeolites. In this context, extensive efforts have been devoted to replacing HCl to produce methylenedianiline (MDA), a key intermediate in polyurethane production. Unfortunately, limited success has been achieved thus far due to low activity, selectivity towards the desired 4,4'-MDA, and rapid catalyst deactivation. Here we report that meso-/microporous hierarchical LTL zeolite exhibits unprecedentedly high activity, selectivity, and stability. The one-dimensional cage-like micropores of LTL promote the bimolecular reaction between two para-aminobenzylaniline intermediates to selectively produce 4,4'-MDA and inhibit the formation of undesired isomers and heavy oligomers. Meanwhile, the secondary mesopores alleviate mass transfer limitations, resulting in a 7.8-fold higher MDA formation rate compared to solely microporous LTL zeolite. Due to suppressed oligomer formation and fast mass transfer, the catalyst exhibits inappreciable deactivation in an industrially relevant continuous flow reactor.
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Affiliation(s)
- Susung Lee
- Department of Chemical and Biomolecular Engineering (BK21 Four), Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, R. Korea
| | - Younghwan Park
- Department of Chemical and Biomolecular Engineering (BK21 Four), Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, R. Korea
| | - Yaejun Baik
- Department of Chemical and Biomolecular Engineering (BK21 Four), Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, R. Korea
| | - Jeong-Chul Kim
- Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS), Daejeon, 34141, R. Korea
| | - Yongjin Lee
- Department of Chemical Engineering, Inha University, Incheon, 22212, R. Korea
| | - Minkee Choi
- Department of Chemical and Biomolecular Engineering (BK21 Four), Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, R. Korea
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9
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Zhang J, Liang C, Dunn JB. Graphite Flows in the U.S.: Insights into a Key Ingredient of Energy Transition. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:3402-3414. [PMID: 36791333 PMCID: PMC9979652 DOI: 10.1021/acs.est.2c08655] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 02/02/2023] [Accepted: 02/03/2023] [Indexed: 06/18/2023]
Abstract
Demand for graphite will grow with expanding use of lithium-ion batteries in the United States. Much graphite is imported, raising supply chain risks. It is therefore imperative to characterize graphite's sources and sinks. Accordingly, we present the first material flow analysis for natural and synthetic graphite in the U.S. The analysis (for 2018) begins with processed graphite trade and includes graphite production, graphite product trade, manufacturing of end products, end product use, and waste management. It considers 11 end-use applications for graphite, two waste management stages, and three recycling pathways. In 2018, 354 thousand tonnes (kt) of processed graphite were consumed in the U.S., including 60 kt natural graphite and 294 kt synthetic graphite. 145 kt of graphite were traded. Refractories and foundries consumed 56% of natural graphite; 42% of synthetic graphite went into making graphite electrodes. Batteries accounted for 10 and 5% of natural and synthetic graphite consumption, respectively; 78% of total graphite used dissipated into the environment; 22% reached the waste disposal stage of which 71% was landfilled and 29% was recycled; and 59 kt of graphite accumulated in in-use stocks. Recycling more graphite and producing graphite from lignin would favorably influence today's supply chain.
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Affiliation(s)
- Jinrui Zhang
- Department
of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Chao Liang
- Institute
for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208, United States
| | - Jennifer B. Dunn
- Department
of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, United States
- Northwestern-Argonne
Institute of Science and Engineering, Evanston, Illinois 60208, United States
- Center
for Engineering Sustainability and Resilience, Northwestern University, Evanston, Illinois 60208 United States
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10
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Dacewicz E, Lenart-Boroń A. Waste Polyurethane Foams as Biomass Carriers in the Treatment Process of Domestic Sewage with Increased Ammonium Nitrogen Content. MATERIALS (BASEL, SWITZERLAND) 2023; 16:619. [PMID: 36676355 PMCID: PMC9862140 DOI: 10.3390/ma16020619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 12/25/2022] [Accepted: 01/04/2023] [Indexed: 06/17/2023]
Abstract
In order to understand the mechanisms of microbial growth on waste polyurethane sponge materials, their effectiveness as biomass carriers in domestic sewage with increased ammonium nitrogen content treatment was assessed. Comparative experiments were carried out in microreactors under steady conditions of batch culture, which allowed for an assessment of different carriers, in the form of flexible foams, rigid foams, and flexible foams placed in full casings. In the studies conducted in continuous cultures, biomass carriers selected in batch culture were used as fillings in the column model. The structure of the microbial community inhabiting the spongy material was determined and the pollutant-removing process from real domestic sewage was assessed. Analyzes using the Illumina sequencing technique allowed for demonstrating that Nitrosomonas and Nitrospira were the predominant nitrifiers in the biomass carrier in the form of waste polyurethane foams (PUF). It was found that anammox bacteria, the presence of which-as unidentified Planctomycetes-was confirmed in the polyurethane sponge material, were also responsible for the high removal of N-NH4+. Burkholderia and Sphingopyxis phyla were identified as the dominant denitrifying bacteria involved in the treatment of domestic sewage with increased content of ammonium nitrogen. The biomass carrier in the form of waste PUF placed additionally in full casings proved to be more beneficial for the proliferation of bacteria involved in nitrification and denitrification processes. On the other hand, waste foams without casings proved to be more suitable for the growth of microorganisms known to perform partial denitrification and may accumulate nitrites (Staphylococcus, Dokdonella). Additionally, the presence of Devosia and Pseudonocardia, which participated in the phosphorus removal process, was found in the waste PUR foams.
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Affiliation(s)
- Ewa Dacewicz
- Department of Sanitary Engineering and Water Management, Faculty of Environmental Engineering and Land Surveying, University of Agriculture in Kraków, Adam Mickiewicz Ave. 24/28, 30-059 Kraków, Poland
| | - Anna Lenart-Boroń
- Department of Microbiology and Biomonitoring, Faculty of Agriculture and Economics, University of Agriculture in Kraków, Adam Mickiewicz Ave. 24/28, 30-059 Kraków, Poland
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11
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Jha A, Shaik KA, Bhardwaj YK, Pant HJ, Chowdhury SR. Electron beam assisted recycling of polyurethane (
PU
) sponge: Turning it into a superabsorbent for wastewater treatment. J Appl Polym Sci 2022. [DOI: 10.1002/app.53545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Atanu Jha
- Homi Bhabha National Institute Mumbai India
- Isotope and Radiation Application Division Bhabha Atomic Research Centre Mumbai India
| | - Khader Abdul Shaik
- Isotope and Radiation Application Division Bhabha Atomic Research Centre Mumbai India
| | - Yatender Kumar Bhardwaj
- Homi Bhabha National Institute Mumbai India
- Radiation Technology Development Division Bhabha Atomic Research Centre Mumbai India
| | - Harish Jagat Pant
- Homi Bhabha National Institute Mumbai India
- Isotope and Radiation Application Division Bhabha Atomic Research Centre Mumbai India
| | - Subhendu Ray Chowdhury
- Homi Bhabha National Institute Mumbai India
- Isotope and Radiation Application Division Bhabha Atomic Research Centre Mumbai India
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12
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Gu X, Wang X, Wang T, Zhu Y, Guo X, Liu S, Zhu S, Liu Y. Analysis of Factors Influencing the Efficiency of Catalysts Used in Waste PU Degradation. Polymers (Basel) 2022; 14:polym14245450. [PMID: 36559817 PMCID: PMC9781215 DOI: 10.3390/polym14245450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 12/02/2022] [Accepted: 12/08/2022] [Indexed: 12/15/2022] Open
Abstract
Polyurethane (PU) is an indispensable part of people's lives. With the development of polyurethane, the disposal of polyurethane waste has become a significant issue around the world. Conventional degradation catalysts have poor dispersion and low degradation efficiency when used in the process of solid degradation into liquid. Therefore, this paper innovatively adopts self-made core-shell nanoscale titanium catalysis, traditional alkali metal catalyst (KOH), and polyol to carry out the glycolysis of waste polyurethane (PU) pipeline foam. The homogenized nanoscale titanium catalyst coated with alcohol gel has an obvious core-shell structure. The alcohol gel not only protects the catalyst but also dissolves with the alcoholysis agent in the process of glycolysis and disperses more evenly into the alcoholysis agent to avoid the phenomenon of nanocatalyst agglomeration, so as to facilitate catalytic cracking without reducing catalyst activity. In this study, investigated and compared the production of renewable polyurethane foam via a one-step method based on use of a homogeneous core-shell nanostructured titanium catalyst vs. a traditional alkaline catalyst in terms of the properties of regenerated polyether polyols as well as of the foams produced from these polyols. The physicochemical properties of regenerated polyether polyols that were analyzed included viscosity, hydroxyl value, and average molecular weight. The regenerated polyurethane foams were characterized based on water absorption, TG, SEM, and thermal conductivity analyses. The results show that, when the addition of homogeneous titanium catalyst was T2 0.050 wt.%, the viscosity of regenerated polyether polyols was the lowest, at 5356.7 mPa·s, which was reduced by 9.97% compared with those obtained using the alkali metal catalyst (KOH). When the amount of titanium catalyst was T3 0.075 wt.%, the hard foam made of regenerated polyurethane prepared by the catalyst showed the best properties, with a compressive strength of 0.168 MPa, which is 4.76% higher than that of the foam prepared using KOH catalyst.
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Affiliation(s)
- Xiaohua Gu
- School of Energy and Building Environment, Guilin University of Aerospace Technology, Guilin 541004, China
- School of Material Science and Engineering, Qiqihar University, Qiqihar 161006, China
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
- Correspondence: (X.G.); (Y.L.); Tel.: +86-18121138868 (X.G.); +86-18078343019 (Y.L.)
| | - Xiaoyao Wang
- School of Material Science and Engineering, Qiqihar University, Qiqihar 161006, China
| | - Tong Wang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
| | - Yanwei Zhu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China
| | - Xinyu Guo
- College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar 161006, China
| | - Siwen Liu
- College of Innovative Material & Energy, Hubei University, Hubei 430062, China
| | - Shangwen Zhu
- School of Energy and Building Environment, Guilin University of Aerospace Technology, Guilin 541004, China
| | - Yan Liu
- School of Energy and Building Environment, Guilin University of Aerospace Technology, Guilin 541004, China
- Correspondence: (X.G.); (Y.L.); Tel.: +86-18121138868 (X.G.); +86-18078343019 (Y.L.)
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13
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Non-Isocyanate Polyurethane Bio-Foam with Inherent Heat and Fire Resistance. Polymers (Basel) 2022; 14:polym14225019. [PMID: 36433146 PMCID: PMC9697988 DOI: 10.3390/polym14225019] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 11/11/2022] [Accepted: 11/17/2022] [Indexed: 11/22/2022] Open
Abstract
Polyurethanes (PUs) are versatile and widespread, particularly as flexible and rigid foams. To avoid isocyanates and other toxic reagents required for synthesis, such as phosgene, alternative synthetic routes have been utilized to produce non-isocyanate polyurethanes (NIPUs). A thermally and flame-resistant rigid NIPU was produced from environmentally benign and bio-sourced ingredients, requiring no catalyst or solvents. A foamed structure was obtained by the addition of glutaraldehyde and four different carboxylic acids: malic acid, maleic acid, citric acid, and aconitic acid. The resulting morphology, thermal degradation, and flame resistance of each foam were compared. The properties vary with each carboxylic acid used, but in each case, peak thermal degradation and peak heat release are postponed by >100 °C compared to commercial rigid PU foam. Furthermore, in a butane torch test, NIPU foams exhibit an 80% higher remaining mass and a 75% reduction in afterburn time, compared to commercial polyurethane. This bio-based polyurethane eliminates the hazards of traditional PUs, while imparting inherent thermal stability and flame resistance uncharacteristic of conventional foams.
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14
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Lomwongsopon P, Varrone C. Critical Review on the Progress of Plastic Bioupcycling Technology as a Potential Solution for Sustainable Plastic Waste Management. Polymers (Basel) 2022; 14:polym14224996. [PMID: 36433123 PMCID: PMC9692586 DOI: 10.3390/polym14224996] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 11/11/2022] [Accepted: 11/14/2022] [Indexed: 11/19/2022] Open
Abstract
Plastic production worldwide has doubled in the last two decades and is expected to reach a four-fold increase by 2050. The durability of plastic makes them a perfect material for many applications, but it is also a key limitation to their end-of-life management. The current plastic lifecycle is far from circular, with only 13% being collected for recycling and 9% being successfully recycled, indicating the failure of current recycling technology. The remaining plastic waste streams are thus incinerated, landfilled, or worse, mismanaged, leading to them leaking into the environment. To promote plastic circularity, keeping material in the loop is a priority and represents a more sustainable solution. This can be achieved through the reuse of plastic items, or by using plastic waste as a resource for new materials, instead of discarding them as waste. As the discovery of plastic-degrading/utilizing microorganisms and enzymes has been extensively reported recently, the possibility of developing biological plastic upcycling processes is opening up. An increasing amount of studies have investigated the use of plastic as a carbon source for biotechnological processes to produce high-value compounds such as bioplastics, biochemicals, and biosurfactants. In the current review, the advancements in fossil-based plastic bio- and thermochemical upcycling technologies are presented and critically discussed. In particular, we highlight the developed (bio)depolymerization coupled with bioconversion/fermentation processes to obtain industrially valuable products. This review is expected to contribute to the future development and scale-up of effective plastic bioupcycling processes that can act as a drive to increase waste removal from the environment and valorize post-consumer plastic streams, thus accelerating the implementation of a circular (plastic) economy.
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15
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Mechanochemistry: An Efficient Way to Recycle Thermoset Polyurethanes. Polymers (Basel) 2022; 14:polym14163277. [PMID: 36015532 PMCID: PMC9412547 DOI: 10.3390/polym14163277] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 08/06/2022] [Accepted: 08/10/2022] [Indexed: 11/17/2022] Open
Abstract
A recycling process of waste thermosetting polyurethane plastics was proposed based on the mechanochemical method, aiming at the three-dimensional network cross-linking structure of thermosetting polyurethane. Orthogonal experimental design was adopted to select three factors of crushing speed, crushing time, and feed amount to determine the best crushing parameters. Then, the waste polyurethane insulation boards were crushed and degraded by the mechanism of regenerative forming with the adjustable speed test machine. Accordingly, the recycled powder was obtained. Finally, nine kinds of polyurethane recycled composite plates were prepared by hot pressing process. The degradation effect of thermosetting polyurethane was analyzed by Fourier transform infrared spectroscopy, scanning electron microscope, and X-ray diffraction. Moreover, the mechanical properties and thermal insulation properties of recycled composite plates were tested and analyzed. The results show that the network cross-linking molecular structure of waste thermosetting polyurethane plastics is destroyed by the effect of mechanochemical action, and methyl and aldehyde groups are decomposed. Therefore, a recycled powder with strong reactivity and plasticity is generated, which improves the activity regeneration ability. After adding thermoplastic resin, the mechanical properties and formability of recycled composite plates are enhanced, with maximum tensile strength up to 9.913 MPa. Correspondingly, the thermal insulation performance of plates is reduced. However, the minimum thermal conductivity can also reach 0.056 W/m·K. This study provides an effective method for the recycling of thermosetting polyurethane plastics.
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16
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Roose TR, Verdoorn DS, Mampuys P, Ruijter E, Maes BUW, Orru RVA. Transition metal-catalysed carbene- and nitrene transfer to carbon monoxide and isocyanides. Chem Soc Rev 2022; 51:5842-5877. [PMID: 35748338 PMCID: PMC9580617 DOI: 10.1039/d1cs00305d] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Indexed: 11/21/2022]
Abstract
Transition metal-catalysed carbene- and nitrene transfer to the C1-building blocks carbon monoxide and isocyanides provides heteroallenes (i.e. ketenes, isocyanates, ketenimines and carbodiimides). These are versatile and reactive compounds allowing in situ transformation towards numerous functional groups and organic compounds, including heterocycles. Both one-pot and tandem processes have been developed providing valuable synthetic methods for the organic chemistry toolbox. This review discusses all known transition metal-catalysed carbene- and nitrene transfer reactions towards carbon monoxide and isocyanides and in situ transformation of the heteroallenes hereby obtained, with a special focus on the general mechanistic considerations.
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Affiliation(s)
- T R Roose
- Department of Chemistry and Pharmaceutical Sciences and Amsterdam Institute for Molecules, Medicines & Systems (AIMMS), Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands.
| | - D S Verdoorn
- Organic Chemistry, Aachen-Maastricht Institute for Biobased Materials (AMIBM), Maastricht University, Urmonderbaan 22, 6167RD Geleen, The Netherlands.
- Organic Synthesis Division, Department of Chemistry, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium.
| | - P Mampuys
- Organic Synthesis Division, Department of Chemistry, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium.
| | - E Ruijter
- Department of Chemistry and Pharmaceutical Sciences and Amsterdam Institute for Molecules, Medicines & Systems (AIMMS), Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands.
| | - B U W Maes
- Organic Synthesis Division, Department of Chemistry, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium.
| | - R V A Orru
- Organic Chemistry, Aachen-Maastricht Institute for Biobased Materials (AMIBM), Maastricht University, Urmonderbaan 22, 6167RD Geleen, The Netherlands.
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17
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Schirmeister CG, Mülhaupt R. Closing the Carbon Loop in the Circular Plastics Economy. Macromol Rapid Commun 2022; 43:e2200247. [PMID: 35635841 DOI: 10.1002/marc.202200247] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 05/07/2022] [Indexed: 11/06/2022]
Abstract
Today, plastics are ubiquitous in everyday life, problem solvers of modern technologies, and crucial for sustainable development. Yet the surge in global demand for plastics of the growing world population has triggered a tidal wave of plastic debris in the environment. Moving from a linear to a zero-waste and carbon-neutral circular plastic economy is vital for the future of the planet. Taming the plastic waste flood requires closing the carbon loop through plastic reuse, mechanical and molecular recycling, carbon capture, and use of the greenhouse gas carbon dioxide. In the quest for eco-friendly products, plastics do not need to be reinvented but tuned for reuse and recycling. Their full potential must be exploited regarding energy, resource, and eco efficiency, waste prevention, circular economy, climate change mitigation, and lowering environmental pollution. Biodegradation holds promise for composting and bio-feedstock recovery, but it is neither the Holy Grail of circular plastics economy nor a panacea for plastic littering. As an alternative to mechanical downcycling, molecular recycling enables both closed-loop recovery of virgin plastics and open-loop valorization, producing hydrogen, fuels, refinery feeds, lubricants, chemicals, and carbonaceous materials. Closing the carbon loop does not create a Perpetuum Mobile and requires renewable energy to achieve sustainability. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Carl G Schirmeister
- Freiburg Materials Research Center and Institute for Macromolecular Chemistry, University of Freiburg, Stefan-Meier-Str. 31, D-79104, Freiburg, Germany
| | - Rolf Mülhaupt
- Sustainability Center, University of Freiburg, Ecker-Str. 4, D-79104, Freiburg, Germany
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