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Mayer PM, Moran KD, Miller EL, Brander SM, Harper S, Garcia-Jaramillo M, Carrasco-Navarro V, Ho KT, Burgess RM, Thornton Hampton LM, Granek EF, McCauley M, McIntyre JK, Kolodziej EP, Hu X, Williams AJ, Beckingham BA, Jackson ME, Sanders-Smith RD, Fender CL, King GA, Bollman M, Kaushal SS, Cunningham BE, Hutton SJ, Lang J, Goss HV, Siddiqui S, Sutton R, Lin D, Mendez M. Where the rubber meets the road: Emerging environmental impacts of tire wear particles and their chemical cocktails. Sci Total Environ 2024; 927:171153. [PMID: 38460683 DOI: 10.1016/j.scitotenv.2024.171153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 02/18/2024] [Accepted: 02/19/2024] [Indexed: 03/11/2024]
Abstract
About 3 billion new tires are produced each year and about 800 million tires become waste annually. Global dependence upon tires produced from natural rubber and petroleum-based compounds represents a persistent and complex environmental problem with only partial and often-times, ineffective solutions. Tire emissions may be in the form of whole tires, tire particles, and chemical compounds, each of which is transported through various atmospheric, terrestrial, and aquatic routes in the natural and built environments. Production and use of tires generates multiple heavy metals, plastics, PAH's, and other compounds that can be toxic alone or as chemical cocktails. Used tires require storage space, are energy intensive to recycle, and generally have few post-wear uses that are not also potential sources of pollutants (e.g., crumb rubber, pavements, burning). Tire particles emitted during use are a major component of microplastics in urban runoff and a source of unique and highly potent toxic substances. Thus, tires represent a ubiquitous and complex pollutant that requires a comprehensive examination to develop effective management and remediation. We approach the issue of tire pollution holistically by examining the life cycle of tires across production, emissions, recycling, and disposal. In this paper, we synthesize recent research and data about the environmental and human health risks associated with the production, use, and disposal of tires and discuss gaps in our knowledge about fate and transport, as well as the toxicology of tire particles and chemical leachates. We examine potential management and remediation approaches for addressing exposure risks across the life cycle of tires. We consider tires as pollutants across three levels: tires in their whole state, as particulates, and as a mixture of chemical cocktails. Finally, we discuss information gaps in our understanding of tires as a pollutant and outline key questions to improve our knowledge and ability to manage and remediate tire pollution.
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Affiliation(s)
- Paul M Mayer
- US Environmental Protection Agency, Office of Research and Development, Center for Public Health and Environmental Assessment, Pacific Ecological Systems Division, Corvallis, OR 97333, United States of America.
| | - Kelly D Moran
- San Francisco Estuary Institute, 4911 Central Ave, Richmond, CA 94804, United States of America.
| | - Ezra L Miller
- San Francisco Estuary Institute, 4911 Central Ave, Richmond, CA 94804, United States of America.
| | - Susanne M Brander
- Department of Fisheries, Wildlife, and Conservation Sciences, Coastal Oregon Marine Experiment Station, Oregon State University, Corvallis, OR 97331, United States of America.
| | - Stacey Harper
- Department of Environmental and Molecular Toxicology, School of Chemical, Biological and Environmental Engineering, Oregon State University, Corvallis, OR 97333, United States of America.
| | - Manuel Garcia-Jaramillo
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331, United States of America.
| | - Victor Carrasco-Navarro
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio Campus, Yliopistonranta 1 E, 70211 Kuopio, Finland.
| | - Kay T Ho
- US Environmental Protection Agency, ORD/CEMM Atlantic Coastal Environmental Sciences Division, Narragansett, RI 02882, United States of America.
| | - Robert M Burgess
- US Environmental Protection Agency, ORD/CEMM Atlantic Coastal Environmental Sciences Division, Narragansett, RI 02882, United States of America.
| | - Leah M Thornton Hampton
- Southern California Coastal Water Research Project, 3535 Harbor Blvd, Suite 110, Costa Mesa, CA 92626, United States of America.
| | - Elise F Granek
- Environmental Science & Management, Portland State University, Portland, OR 97201, United States of America.
| | - Margaret McCauley
- US Environmental Protection Agency, Region 10, Seattle, WA 98101, United States of America.
| | - Jenifer K McIntyre
- School of the Environment, Washington State University, Puyallup Research & Extension Center, Washington Stormwater Center, 2606 W Pioneer Ave, Puyallup, WA 98371, United States of America.
| | - Edward P Kolodziej
- Interdisciplinary Arts and Sciences (UW Tacoma), Civil and Environmental Engineering (UW Seattle), Center for Urban Waters, University of Washington, Tacoma, WA 98402, United States of America.
| | - Ximin Hu
- Civil and Environmental Engineering (UW Seattle), University of Washington, Seattle, WA 98195, United States of America.
| | - Antony J Williams
- US Environmental Protection Agency, Center for Computational Toxicology and Exposure, Chemical Characterization and Exposure Division, Computational Chemistry & Cheminformatics Branch, 109 T.W. Alexander Drive, Research Triangle Park, NC 27711, United States of America.
| | - Barbara A Beckingham
- Department of Geology & Environmental Geosciences, College of Charleston, Charleston, SC, 66 George Street Charleston, SC 29424, United States of America.
| | - Miranda E Jackson
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331, United States of America.
| | - Rhea D Sanders-Smith
- Washington State Department of Ecology, 300 Desmond Drive SE, Lacey, WA 98503, United States of America.
| | - Chloe L Fender
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331, United States of America.
| | - George A King
- CSS, Inc., 200 SW 35th St, Corvallis, OR 97333, United States of America.
| | - Michael Bollman
- US Environmental Protection Agency, Office of Research and Development, Center for Public Health and Environmental Assessment, Pacific Ecological Systems Division, Corvallis, OR 97333, United States of America.
| | - Sujay S Kaushal
- Department of Geology and Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD 20740, United States of America.
| | - Brittany E Cunningham
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97333, United States of America.
| | - Sara J Hutton
- GSI Environmental, Inc., Olympia, Washington 98502, USA.
| | - Jackelyn Lang
- Department of Anatomy, Physiology, and Cell Biology, Department of Medicine and Epidemiology and the Karen C. Drayer Wildlife Health Center, University of California, Davis School of Veterinary Medicine, Davis, CA 95616, United States of America.
| | - Heather V Goss
- US Environmental Protection Agency, Office of Water, Office of Wastewater Management, Washington, DC 20004, United States of America.
| | - Samreen Siddiqui
- Department of Fisheries, Wildlife, and Conservation Sciences, Coastal Oregon Marine Experiment Station, Oregon State University, Corvallis, OR 97331, United States of America.
| | - Rebecca Sutton
- San Francisco Estuary Institute, 4911 Central Ave, Richmond, CA 94804, United States of America.
| | - Diana Lin
- San Francisco Estuary Institute, 4911 Central Ave, Richmond, CA 94804, United States of America.
| | - Miguel Mendez
- San Francisco Estuary Institute, 4911 Central Ave, Richmond, CA 94804, United States of America.
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2
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Chen Y, Hu K, Chen Y, Zhang T, Zhang W. Preparation and modification mechanism study of microwave-treated crumb rubber and waste engine oil-modified asphalt. Environ Sci Pollut Res Int 2024; 31:12483-12498. [PMID: 38231330 DOI: 10.1007/s11356-023-31144-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 11/16/2023] [Indexed: 01/18/2024]
Abstract
The objective of this study was to characterize the performance of waste engine oil (WEO) and microwave-treated crumb rubber (CR)-modified asphalt (WEO-MCRA) and analyze the modification mechanism. The viscosity and dynamic shear rheological (DSR) tests were carried out to evaluate the viscoelasticity property of WEO-MCRA. The storage stability and fluorescence microscope (FM) tests were used to characterize the compatibility of the components. The Fourier transform infrared spectroscopy (FTIR) and molecular dynamic simulation were introduced to analyze the change of function groups and modification mechanism. The results demonstrated that introducing Wt.20% CR treated with microwave and Wt.6% WEO obtained a lower viscosity, excellent storage stability, and satisfactory elasticity properties of asphalt. The morphology of modifiers presented a thread-like structure microscopic with the range of WEO content Wt.3%-Wt.6%. Molecular dynamic simulations revealed that the aromatic may be intensively absorbed by CR and increase the likelihood of phase separation. WEO reduced the binding energy of CR to aromatic from 178.0 to 151.5 kcal/mol, which will contribute to the disaggregation of CR clusters. The diffusion coefficient shows a more obvious decrease with the addition of WEO and microwave treatment, which will benefit the stability of the asphalt. This study can provide a reference for the recycling of CR and WEO.
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Affiliation(s)
- Yan Chen
- College of Civil Engineering, Henan University of Technology, Zhengzhou, 450001, China
| | - Kui Hu
- College of Civil Engineering, Henan University of Technology, Zhengzhou, 450001, China.
| | - Yujing Chen
- College of Civil Engineering, Henan University of Technology, Zhengzhou, 450001, China
| | - Taoli Zhang
- College of Civil Engineering, Henan University of Technology, Zhengzhou, 450001, China
| | - Wengang Zhang
- School of Civil Engineering and Geomatics, Shandong University of Technology, Zibo, 255000, China
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3
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Moreno T, Balasch A, Bartrolí R, Eljarrat E. A new look at rubber recycling and recreational surfaces: The inorganic and OPE chemistry of vulcanised elastomers used in playgrounds and sports facilities. Sci Total Environ 2023; 868:161648. [PMID: 36669664 DOI: 10.1016/j.scitotenv.2023.161648] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 12/23/2022] [Accepted: 01/12/2023] [Indexed: 06/17/2023]
Abstract
We revisit current understanding of the chemical complexity of different kinds of particulate vulcanised elastomers widely used in playgrounds and sports fields, adding new data on trace element and organophosphate ester contents of used tyre and EDPM crumb rubber. Enrichments in elements such as Zn, S, Co, Bi and Nd relate to the vulcanised mixtures created during manufacture. Zinc concentrations vary across an order of magnitude, being highest in our used tyre particulate samples (up to 2.4 %). In contrast, other trace element variations are due to coloured pigments causing increases in Cu and Zr (blue), Cr (green), and Fe and Sn (red and yellow) concentrations. The use of pale fillers such as CaCO3 and clay minerals (rather than carbon black) strongly influences Ca and Al concentrations, which are much higher in the coloured EPDM than in black used tyre crumb rubber. Representatives from all three of the main organophosphate ester (OPE) groups, namely chlorinated (e.g. TCEP, TCIPP, TDCPP), alkyl (e.g. TEHP, TEP, TNBP, TBOEP) and aryl (e.g. TPHP, EHDPP, TCP) were identified, confirming how these chemicals are commonly used in modern rubber compounding as flame retardants and plasticisers. Elevated concentrations of TEHP (up to 117 μg/g) in coloured-coated used tyre turf infill crumb rubbers were traced to the coating rather than the crumb rubber itself. The presence and weathering behaviour of OPEs in recreational crumb rubber materials deserve closer investigation. The ecological "onehealth" impact of potentially toxic substances present in recreational crumb rubbers will depend on if and how they are released during play and sports activities, maintenance procedures, and natural weathering. We argue that detailed chemical data on these materials should be available to buyers, as manufacturers strive to reduce ecotoxin content as part of the quest towards sustainable use and recycling of vulcanised elastomers.
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Affiliation(s)
- Teresa Moreno
- Institute for Environmental Assessment and Water Studies (IDAEA), CSIC, 18-26 Jordi Girona, Barcelona 08034, Spain.
| | - Aleix Balasch
- Institute for Environmental Assessment and Water Studies (IDAEA), CSIC, 18-26 Jordi Girona, Barcelona 08034, Spain
| | - Rafael Bartrolí
- Institute for Environmental Assessment and Water Studies (IDAEA), CSIC, 18-26 Jordi Girona, Barcelona 08034, Spain
| | - Ethel Eljarrat
- Institute for Environmental Assessment and Water Studies (IDAEA), CSIC, 18-26 Jordi Girona, Barcelona 08034, Spain
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4
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Manaila E, Craciun G, Lungu IB, Dumitru Grivei MD, Maria Daniela S. Degradation by Electron Beam Irradiation of Some Elastomeric Composites Sulphur Vulcanized. Materials (Basel) 2023; 16:2152. [PMID: 36984033 PMCID: PMC10058693 DOI: 10.3390/ma16062152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 03/02/2023] [Accepted: 03/03/2023] [Indexed: 06/18/2023]
Abstract
Composites based on natural rubber and plasticized starch obtained by the conventional method of sulfur cross-linking using four types of vulcanization accelerators (Diphenyl guanidine, 2-Mercaptobenzothiazole, N-Cyclohexyl-2-benzothiazole sulfenamide, and Tetramethylthiuram disulfide) were irradiated with an electron beam in the dose range of 150 and 450 kGy for the purpose of degradation. The vulcanization accelerators were used in different percentages and combinations, resulting in four mixtures with different potential during the cross-linking process (synergistic, activator, or additive). The resulting composites were investigated before and after irradiation in order to establish a connection between the type of accelerator mixture, irradiation dose, and composite properties (gel fraction, cross-linking degree, water absorption, mass loss in water and toluene, mechanical properties, and structural and morphological properties). The results showed that the mixtures became sensitive at the irradiation dose of 300 kGy and at the irradiation dose of 450 kGy, and the consequences of the degradation processes were discussed.
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Affiliation(s)
- Elena Manaila
- Electron Accelerators Laboratory, National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor St., 077125 Magurele, Romania
| | - Gabriela Craciun
- Electron Accelerators Laboratory, National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor St., 077125 Magurele, Romania
| | - Ion Bogdan Lungu
- Multipurpose Irradiation Facility Center—IRASM, Horia Hulubei National Institute for R&D in Physics and Nuclear Engineering, 30 Reactorului St., 077125 Magurele, Romania
| | - Marius Daniel Dumitru Grivei
- Electron Accelerators Laboratory, National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor St., 077125 Magurele, Romania
| | - Stelescu Maria Daniela
- National R&D Institute for Textile and Leather—Leather and Footwear Research Institute, 93 Ion Minulescu St., 031215 Bucharest, Romania
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5
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Cataldo F. Thermochemistry of Sulfur-Based Vulcanization and of Devulcanized and Recycled Natural Rubber Compounds. Int J Mol Sci 2023; 24:ijms24032623. [PMID: 36768945 PMCID: PMC9916552 DOI: 10.3390/ijms24032623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 01/19/2023] [Accepted: 01/21/2023] [Indexed: 01/31/2023] Open
Abstract
The vulcanization of rubber compounds is an exothermal process. A carbon black-filled and natural rubber-based (NR) formulation was mixed with different levels of sulfur (0.5, 1.0, 2.0, 4.0 and 6.0 phr) and studied with differential scanning calorimetry (DSC) for the determination of the vulcanization enthalpy. It was found that the vulcanization enthalpy is dependent on the amount of sulfur present in the compound and the vulcanization heat released was -18.4 kJ/mol S if referred to the entire rubber compound formulation or -46.0 kJ/mol S if the heat released is referred only to the NR present in the compound. The activation energy for the vulcanization of the rubber compounds was also determined by a DSC study at 49 kJ/mol and found to be quite independent from the sulfur content of the compounds under study. A simplified thermochemical model is proposed to explain the main reactions occurring during the vulcanization. The model correctly predicts that the vulcanization is an exothermal process although it gives an overestimation of the vulcanization enthalpy (which is larger for the EV vulcanization package and smaller for the conventional vulcanization system). If the devulcanization is conducted mechanochemically in order to break selectively the sulfur-based crosslinks, then the natural rubber compounds recovered from used tires can be re-vulcanized again and the exothermicity of such process can be measured satisfactorily with DSC analysis. This paper not only proposes a simplified mechanism of vulcanization and devulcanization but also proposes an analytical method to check the devulcanization status of the recycled rubber compound in order to distinguish truly devulcanized rubber from reclaimed rubber.
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Affiliation(s)
- Franco Cataldo
- Actinium Chemical Research, Via Casilina 1626A, 00133 Rome, Italy
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6
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Fathy E, Hassan MM, Elnaggar MY. Short nylon tire cord and gamma irradiation impact on SBR/ultrasonic and mechanochemical devulcanized rubber blends. RADIOCHIM ACTA 2023. [DOI: 10.1515/ract-2022-0077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Abstract
Devulcanization of discarded tire rubber (WR) has remained of prior attention to numerous researchers, aiming for unlimited commercial profits upon modification, especially to serve as a substituent for virgin rubber. In this concern, composites of styrene butadiene rubber (SBR) and devulcanized waste rubber, developed via two techniques: mechanochemical (DRm) and ultrasonic (DRus), and reinforced with short nylon tire cord (SNF), namely at a filling ratio of 3 and 5 phr were fabricated. All prepared specimens were exposed to various gamma radiation doses, namely 50, 100, and 150 kGy. The post-radiation characterization was investigated by FTIR and SEM techniques. Radiation-induced crosslinking density of the polymer composites was calculated and correlated with the different mechanical features. Furthermore, the TGA technique and activation energy measurement were implemented in studying the thermal behavior of the products. Incorporation of 5 phr SNF set out the thermal stability order: SBR/DRm/5 SNF > SBR/DRus/5 SNF > SBR/5 SNF. Ionizing irradiation of all composite–SNF formulations derived to a marked improvement in TS data as a result of creating further crosslinking within the polymeric matrix, reaching a maximum by the integral dose 150 kGy. The results were appreciably compared to a recently published study that applied reinforced tire fiber with polyester, as another cord utilized in the manufacture of tires. It is found that TS data observed by irradiation with 150 kGy of SBR/3 SNF, SBR/DRm/3 SNF, and SBR/DRus/3 SNF are respectively as follows: 3.7, 2.5, and 2.4 MPa, whereas the corresponding reported values for PTC reinforced counterpart blends were: 2, 1.7 and 1.8 MPa. Similarly, the TS respective values of SBR/5 SNF, SBR/DRm/5 SNF and SBR/DRus are 2.5, 1.9, and 2.2 MPa, whereas their counterparts reinforced with 5 phr PTC recorded 1.6, 1.8, and 1.2 MPa. SNF-reinforced SBR, SBR/DRm, and SBR/DRus were superior in their properties to PTC-reinforced counterpart specimens.
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Affiliation(s)
- E.S. Fathy
- Department of Polymer Chemistry , National Centre for Radiation Research and Technology (NCRRT), Egyptian Atomic Energy Authority (EAEA) , Cairo , Egypt
| | - Medhat M. Hassan
- Department of Polymer Chemistry , National Centre for Radiation Research and Technology (NCRRT), Egyptian Atomic Energy Authority (EAEA) , Cairo , Egypt
| | - Mona Y. Elnaggar
- Department of Polymer Chemistry , National Centre for Radiation Research and Technology (NCRRT), Egyptian Atomic Energy Authority (EAEA) , Cairo , Egypt
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7
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Zhang L, Zhang C, Zhang Z, Wang H, Wang S. Characterization, Properties and Mixing Mechanism of Rubber Asphalt Colloid for Sustainable Infrastructure. Polymers (Basel) 2022; 14:4429. [PMID: 36298007 PMCID: PMC9608875 DOI: 10.3390/polym14204429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 10/06/2022] [Accepted: 10/18/2022] [Indexed: 11/24/2022] Open
Abstract
Rubber asphalt has always been considered to have the most potential for the disposal of waste tires as sustainable infrastructure. However, the covalently cross-linked tire rubber presents an extreme challenge in reusing waste rubbers in roads. Rubberized asphalt with finely dispersed or colloidal structure has been regarded as a potential binder used as road material because of the improved properties in terms of storage stability, easy processing and high content of incorporation. However, the mixing mechanism between the finely dispersed rubber on micro-nano scale with asphalt is still not clear, which restricts its further development as value-added material. Devulcanized rubber (DR) was introduced to improve the compatibility between asphalt and rubber. The basic chemicals of DR and asphalt were introduced based on their structures. Furthermore, the interactions between DR and asphalt were discussed according to the functional elements at different levels, and the concept of DR as “the fifth component” of asphalt was put forward. Finally, high performance, environmental and economic effects and applications of devulcanized-rubber-modified asphalt (DRMA) were discussed. The review is expected to provide a guide for the wide application of DRMA, which is still restricted by poor compatibility and bad stability during processing, storage and recycling.
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8
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Pérez-Campos R, Fayos-Fernández J, Monzó-Cabrera J, Martín Salamanca F, López Valentín J, Catalá-Civera JM, Plaza-González P, Sánchez-Marín JR. Dynamic Permittivity Measurement of Ground-Tire Rubber (GTR) during Microwave-Assisted Devulcanization. Polymers (Basel) 2022; 14:polym14173543. [PMID: 36080618 PMCID: PMC9460287 DOI: 10.3390/polym14173543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 08/14/2022] [Accepted: 08/24/2022] [Indexed: 11/16/2022] Open
Abstract
Many efforts are being made to find innovative ways of recycling rubber from end-of-life tires (ELTs), also called ground tire Rubber (GTR). Recycling through devulcanization allows the reintroduction of rubber back into the manufacturing industry. Such a process requires providing enough energy to break the sulfur links, while preventing damage to the polymeric chain. Microwave heating is controllable, efficient, and it does not rely on conventional heating mechanisms (conduction, convection) which may involve high heating losses, but rather on direct dielectric heating. However, to adequately control the microwave-assisted devulcanization performance, a thorough knowledge of the GTR permittivity versus temperature is required. In this work, GTR permittivity was monitored during its devulcanization. A resonant technique based on a dual-mode cylindrical cavity was used to simultaneously heat rubber and measure its permittivity at around 2 GHz. The results show sharp changes in the GTR permittivity at 160 and 190 °C. After the GTR cooled down, a shifted permittivity evidences a change in the GTR structure caused by the devulcanization process. Microwave-assisted devulcanization effectiveness is proven through time-domain nuclear magnetic resonance (NMR) measurements, by verifying the decrease in the cross-link density of processed GTR samples compared to the original sample.
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Affiliation(s)
- Rafael Pérez-Campos
- Departamento de Tecnologías de la Información y las Comunicaciones, Universidad Politécnica de Cartagena (UPCT), 30202 Cartagena, Spain
| | - José Fayos-Fernández
- Departamento de Tecnologías de la Información y las Comunicaciones, Universidad Politécnica de Cartagena (UPCT), 30202 Cartagena, Spain
- Correspondence: ; Tel.: +34-968-326-595
| | - Juan Monzó-Cabrera
- Departamento de Tecnologías de la Información y las Comunicaciones, Universidad Politécnica de Cartagena (UPCT), 30202 Cartagena, Spain
| | - Fernando Martín Salamanca
- Instituto de Ciencia y Tecnología de Polímeros (ICTP-CSIC), Juan de la Cierva 3, 28006 Madrid, Spain
| | - Juan López Valentín
- Instituto de Ciencia y Tecnología de Polímeros (ICTP-CSIC), Juan de la Cierva 3, 28006 Madrid, Spain
| | - José Manuel Catalá-Civera
- Instituto de Tecnologías de la Información y las Comunicaciones, Universitat Politècnica de València (UPV), 46022 Valencia, Spain
| | - Pedro Plaza-González
- Instituto de Tecnologías de la Información y las Comunicaciones, Universitat Politècnica de València (UPV), 46022 Valencia, Spain
| | - Juan Rafael Sánchez-Marín
- Instituto de Tecnologías de la Información y las Comunicaciones, Universitat Politècnica de València (UPV), 46022 Valencia, Spain
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9
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Ye N, Wu Z, Wu X, Lu Y, Zhang L. Performance Enhancement of Polymerized, Functionalized Solution Styrene–Butadiene Rubber Composites Using Oligomeric Resin towards Extremely Safe and Energy-Saving Tires. Polymers (Basel) 2022; 14:2928. [PMID: 35890704 PMCID: PMC9316608 DOI: 10.3390/polym14142928] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 06/20/2022] [Accepted: 06/26/2022] [Indexed: 02/04/2023] Open
Abstract
Polymerized, functionalized solution styrene–butadiene rubber (F-SSBR) is a new type of polymerized styrene–butadiene rubber solution containing specific terminal groups, which can be used in treads for high performances. However, the wet skid resistance related to safety, the rolling resistance to energy consumption, and the wear resistance to service life are often contradictory and form the performance “magic triangle”. In this work, oligomeric resins, including Coumarone resin, C9 resin, C5/C9 resin and a styrene-α-methyl styrene copolymer (SSC), were used as tire functional additives and selected to replace treated distillate aromatic extract (TDAE) to improve the performances of silica-filled F-SSBR composites. The C9 resin, C5/C9 resin and SSC could enhance the modulus at 300% and tensile strength of the F-SSBR composite. The four resins could improve the wet skid resistance and wear resistance of the composites. However, Coumarone resin caused poor silica dispersion in the F-SSBR matrix and eventually, the lower modulus, higher loss factor at 60 °C and the higher heat buildup in the composite were comparative to the composite with TDAE. Furthermore, the synergistic effect of the C5/C9 resin and SSC was found to improve the mechanical performance of the composites and it resulted in higher tensile strength and modulus, and a lower heat buildup, compared to the case when only TDAE was used. It is noted that the properties “magic triangle” was broken by the C5/C9 resin and SSC, and the C5/C910T15 increased the wet skid resistance by 21.7%, fuel-saving rate by 2.3%, and wear resistance by 8.3%, while S20T5 increased the wet skid resistance by 30.4%, fuel-saving rate by 7%, and wear resistance by 25% compared with CG.
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10
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Wang S, Yan Y, Gao X, Zhang H, Cui Y, He Q, Wang Y, Wang X. Emission Characteristics and Health Risks of Volatile Organic Compounds (VOCs) Measured in a Typical Recycled Rubber Plant in China. IJERPH 2022; 19:8753. [PMID: 35886605 PMCID: PMC9322705 DOI: 10.3390/ijerph19148753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 07/13/2022] [Accepted: 07/13/2022] [Indexed: 11/17/2022]
Abstract
The continued development of the automotive industry has led to a rapid increase in the amount of waste rubber tires, the problem of “black pollution” has become more serious but is often ignored. In this study, the emission characteristics, health risks, and environmental effects of volatile organic compounds (VOCs) from a typical, recycled rubber plant were studied. A total of 15 samples were collected by summa canisters, and 100 VOC species were detected by the GC/MS-FID system. In this study, the total VOCs (TVOCs) concentration ranged from 1000 ± 99 to 19,700 ± 19,000 µg/m3, aromatics and alkanes were the predominant components, and m/p-xylene (14.63 ± 4.07%–48.87 ± 3.20%) could be possibly regarded as a VOCs emission marker. We also found that specific similarities and differences in VOCs emission characteristics in each process were affected by raw materials, production conditions, and process equipment. The assessment of health risks showed that devulcanizing and cooling had both non-carcinogenic and carcinogenic risks, yarding had carcinogenic risks, and open training and refining had potential carcinogenic risks. Moreover, m/p-xylene and benzene were the main non-carcinogenic species, while benzene, ethylbenzene, and carbon tetrachloride were the dominant risk compounds. In the evaluation results of LOH, m/p-xylene (25.26–67.87%) was identified as the most key individual species and should be prioritized for control. In conclusion, the research results will provide the necessary reference to standardize the measurement method of the VOCs source component spectrum and build a localized source component spectrum.
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Khozemy EE, Radi H, Mazied NA. Upcycling of waste polyethylene and cement kiln dust to produce polymeric composite sheets using gamma irradiation. Polym Bull (Berl) 2022. [DOI: 10.1007/s00289-022-04310-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
AbstractCement kiln dust (CKD) is a residue produced during the manufacture of cement that contains hazardous solid waste of high toxicity that affects the environment and public health. In this study, the possibility of using CKD as a filler in the plastic and rubber industry was studied. The effect of CKD concentration and gamma irradiation dose on the mechanical and physico-chemical properties of the composite containing waste polyethylene/devulcanized rubber/EPDM rubber (named blank) was investigated. Different concentrations of CKD, namely 10, 15, 20, and 30 phr (part per hundred part of composite), were used. The results indicated that this composite (blended with CKD) properties were improved. The most significant improvement was achieved by using CKD concentration of 20 phr at the dose of 100 kGy of gamma irradiation. These findings were demonstrated by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and thermogravimetric analysis.
Graphical abstract
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12
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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: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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13
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Gumede JI, Hlangothi BG, Woolard CD, Hlangothi SP. Organic chemical devulcanization of rubber vulcanizates in supercritical carbon dioxide and associated less eco-unfriendly approaches: A review. Waste Manag Res 2022; 40:490-503. [PMID: 33829913 DOI: 10.1177/0734242x211008515] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
There is a growing need to recover raw materials from waste due to increasing environmental concerns and the widely adopted transition to circular economy. For waste tyres, it is necessary to continuously develop methods and processes that can devulcanize rubber vulcanizates into rubber products with qualities and properties that can closely match those of the virgin rubber. Currently, the most common, due to its efficiency and perceived eco-friendliness in recovering raw rubber from waste rubbers, such as tyres, is devulcanization in supercritical carbon dioxide (scCO2) using commercial and typical devulcanizing agents. The scCO2 has been generally accepted as an attractive alternative to the traditional liquid-based devulcanization media because of the resultant devulcanized rubber has relatively better quality than other processes. For instance, when scCO2 is employed to recover rubber from waste tyres (e.g. truck tyres) and the recovered rubber is blended with virgin natural rubber (NR) in various compositions, the curing and mechanical properties of the blends closely match those of virgin NR. The atmospheric toxicity and cost of the commonly used devulcanization materials like chemical agents, oils and solvents have enabled a shift towards utilization of greener (mainly organic) and readily available devulcanization chemical components. This literature review paper discusses the approaches, which have less negative impact on the environment, in chemical devulcanization of rubber vulcanizates. A special focus has been on thermo-chemical devulcanization of waste tyres in scCO2 using common organic devulcanizing agents.
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Affiliation(s)
- Jabulani I Gumede
- Department of Chemistry, Centre for Rubber Science and Technology, Nelson Mandela University, Port Elizabeth, South Africa
| | - Buyiswa G Hlangothi
- Department of Chemistry, Centre for Rubber Science and Technology, Nelson Mandela University, Port Elizabeth, South Africa
| | - Chris D Woolard
- Department of Mechanical Engineering, Centre for Materials Engineering, University of Cape Town, Rondebosch, South Africa
| | - Shanganyane P Hlangothi
- Department of Chemistry, Centre for Rubber Science and Technology, Nelson Mandela University, Port Elizabeth, South Africa
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Zhang Y, Yu X, Cheng Z. Research on the Application of Synthetic Polymer Materials in Contemporary Public Art. Polymers (Basel) 2022; 14:1208. [PMID: 35335537 PMCID: PMC8954564 DOI: 10.3390/polym14061208] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 03/11/2022] [Accepted: 03/15/2022] [Indexed: 02/06/2023] Open
Abstract
Synthetic polymer materials are widely used in contemporary public art creation. This review summarizes the application methods and current situation of synthetic polymer materials in public art, analyzes the reasons behind them and points out the deficiencies in this research field. Finally, the development trend of the interaction between synthetic polymer materials and public art is put forward.
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Formela K, Kurańska M, Barczewski M. Recent Advances in Development of Waste-Based Polymer Materials: A Review. Polymers (Basel) 2022; 14:1050. [PMID: 35267873 PMCID: PMC8914771 DOI: 10.3390/polym14051050] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 02/04/2022] [Accepted: 03/01/2022] [Indexed: 11/16/2022] Open
Abstract
Limited petroleum sources, suitable law regulations, and higher awareness within society has caused sustainable development of manufacturing and recycling of polymer blends and composites to be gaining increasing attention. This work aims to report recent advances in the manufacturing of environmentally friendly and low-cost polymer materials based on post-production and post-consumer wastes. Sustainable development of three groups of materials: wood polymer composites, polyurethane foams, and rubber recycling products were comprehensively described. Special attention was focused on examples of industrially applicable technologies developed in Poland over the last five years. Moreover, current trends and limitations in the future “green” development of waste-based polymer materials were also discussed.
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16
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Kirshanov K, Toms R, Melnikov P, Gervald A. Investigation of Polyester Tire Cord Glycolysis Accompanied by Rubber Crumb Devulcanization. Polymers (Basel) 2022; 14:polym14040684. [PMID: 35215597 PMCID: PMC8878447 DOI: 10.3390/polym14040684] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 02/04/2022] [Accepted: 02/08/2022] [Indexed: 11/29/2022] Open
Abstract
A new method for the recycling of a polyester tire cord under the action of oligoethylene terephthalates, bis(2-hydroxyethyl) terephthalate and ethylene glycol has been proposed. The method involves simultaneous homogeneous glycolysis of polyethylene terephthalate and devulcanization of crumb rubber. Polyester cord and glycolysates were characterized by FTIR spectroscopy and gel permeation chromatography (GPC). The devulcanization process was investigated by swelling-based methods. The rate of the proposed method of homogeneous glycolysis in a melt phase was proved to be higher than one of the heterogeneous glycolysis. The assumption of a more efficient devulcanization in the presence of a softener was also confirmed. The degree of devulcanization 46.07%, the apparent degree of swelling 167.4%, and the apparent swelling rate constant 0.0902 min−1 were achieved. The results indicate that the proposed method made it possible to carry out the glycolysis of the polyester cord of the tire more deeply than the known heterogeneous glycolysis with various agents, but further research is needed for industrial implementation.
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17
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Irtiseva K, Mosina M, Tumilovica A, Lapkovskis V, Mironovs V, Ozolins J, Stepanova V, Shishkin A. Application of Granular Biocomposites Based on Homogenised Peat for Absorption of Oil Products. Materials (Basel) 2022; 15:1306. [PMID: 35207843 DOI: 10.3390/ma15041306] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 02/02/2022] [Accepted: 02/04/2022] [Indexed: 02/04/2023]
Abstract
Among the various methods for collecting oil spills and oil products, including from the water surface, one of the most effective is the use of sorbents. In this work, three-component bio-based composite granular adsorbents were produced and studied for oil products’ pollution collection. A bio-based binder made of peat, devulcanised crumb rubber from used tyres, and part fly ash as cenospheres were used for absorbent production. The structure, surface morphology, porosity, mechanical properties, and sorption kinetics of the obtained samples were studied. Composite hydrophobicity and sorption capacity to oil products, such as diesel fuel (DF) and motor oil (MO), were determined. The obtained pellets are characterised by a sufficiently pronounced ability to absorb oil products such as DF. As the amount of CR in the granules increases, the diesel absorption capacity increases significantly. The case of 30-70-0 is almost three times higher than the granules from homogenised peat. The increase in q is due to two factors: the pronounced surface hydrophobicity of the samples (Θ = 152°) and a heterogeneous porous granule structure. The presence of the cenosphere in the biocomposite reduces its surface hydrophobicity while increasing the diesel absorption capacity. Relatively rapid realisation of the maximum saturation by the MO was noted. In common, the designed absorbent shows up to 0.7 g·g−1 sorption capacity for MO and up to 1.55 g·g−1 sorption capacity for diesel. A possible mechanism of DF absorption and the limiting stages of the process approximated for different kinetic models are discussed. The Weber–Morris diffusion model is used to primarily distinguish the limiting effect of the external and internal diffusion of the adsorbate on the absorption process.
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19
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Kundariya N, Mohanty SS, Varjani S, Hao Ngo H, W C Wong J, Taherzadeh MJ, Chang JS, Yong Ng H, Kim SH, Bui XT. A review on integrated approaches for municipal solid waste for environmental and economical relevance: Monitoring tools, technologies, and strategic innovations. Bioresour Technol 2021; 342:125982. [PMID: 34592615 DOI: 10.1016/j.biortech.2021.125982] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 09/15/2021] [Accepted: 09/15/2021] [Indexed: 06/13/2023]
Abstract
Rapid population growth, combined with increased industrialization, has exacerbated the issue of solid waste management. Poor management of municipal solid waste (MSW) not only has detrimental environmental consequences but also puts public health at risk and introduces several other socioeconomic problems. Many developing countries are grappling with the problem of safe disposing of large amounts of produced municipal solid waste. Unmanaged municipal solid waste pollutes the environment, so its use as a potential renewable energy source would aid in meeting both increased energy needs and waste management. This review investigates emerging strategies and monitoring tools for municipal solid waste management. Waste monitoring using high-end technologies and energy recovery from MSW has been discussed. It comprehensively covers environmental and economic relevance of waste management technologies based on innovations achieved through the integration of approaches.
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Affiliation(s)
- Nidhi Kundariya
- Gujarat Pollution Control Board, Gandhinagar-382 010, Gujarat, India; Kadi Sarva Vishwavidyalaya, Gandhinagar, Gujarat 382015, India
| | - Swayansu Sabyasachi Mohanty
- Gujarat Pollution Control Board, Gandhinagar-382 010, Gujarat, India; Central University of Gujarat, Gandhinagar- 382030, Gujarat, India
| | - Sunita Varjani
- Gujarat Pollution Control Board, Gandhinagar-382 010, Gujarat, India.
| | - Huu Hao Ngo
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Jonathan W C Wong
- Institute of Bioresource and Agriculture, Hong Kong Baptist University, Hong Kong, PR China
| | | | - Jo-Shu Chang
- Department of Chemical Engineering and Materials Science, College of Engineering, Tunghai University, Taichung, Taiwan; Research Center for Smart Sustainable Circular Economy, Tunghai University, Taichung, Taiwan; Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan
| | - How Yong Ng
- National University of Singapore, Environmental Research Institute, 5A Engineering Drive 1, Singapore 117411, Singapore
| | - Sang-Hyoun Kim
- School of Civil and Environmental Engineering, Yonsei University, Seoul 03722, Republic of South Korea
| | - Xuan-Thanh Bui
- Faculty of Environment and Natural Resources, Ho Chi Minh City University of Technology (HCMUT), Ho Chi Minh City 700000, Vietnam; Key Laboratory of Advanced Waste Treatment Technology, Vietnam National University Ho Chi Minh (VNU-HCM), Linh Trung ward, Thu Duc district, Ho Chi Minh City 700000, Vietnam
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20
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Wiśniewska P, Zedler Ł, Formela K. Processing, Performance Properties, and Storage Stability of Ground Tire Rubber Modified by Dicumyl Peroxide and Ethylene-Vinyl Acetate Copolymers. Polymers (Basel) 2021; 13:4014. [PMID: 34833313 DOI: 10.3390/polym13224014] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/12/2021] [Accepted: 11/15/2021] [Indexed: 02/06/2023] Open
Abstract
In this paper, ground tire rubber was modified with dicumyl peroxide and a variable content (in the range of 0–15 phr) of ethylene-vinyl acetate copolymers characterized by different vinyl acetate contents (in the range of 18–39 wt.%). Modification of ground tire rubber was performed via an auto-thermal extrusion process in which heat was generated during internal shearing of the material inside the extruder barrel. The processing, performance properties, and storage stability of modified reclaimed ground tire rubber were evaluated based on specific mechanical energy, infrared camera images, an oscillating disc rheometer, tensile tests, equilibrium swelling, gas chromatography combined with a flame ionization detector, and gas chromatography with mass spectrometry. It was found that the developed formulas of modified GTR allowed the preparation of materials characterized by tensile strengths in the range of 2.6–9.3 MPa and elongation at break in the range of 78–225%. Moreover, the prepared materials showed good storage stability for at least three months and satisfied processability with commercial rubbers (natural rubber, styrene-butadiene rubber).
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21
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Yerezhep D, Tychengulova A, Sokolov D, Aldiyarov A. A Multifaceted Approach for Cryogenic Waste Tire Recycling. Polymers (Basel) 2021; 13:2494. [PMID: 34372098 DOI: 10.3390/polym13152494] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 07/23/2021] [Accepted: 07/26/2021] [Indexed: 11/21/2022] Open
Abstract
One of the important aspects for degradation of the life quality is the ever increasing volume and range of industrial wastes. Polymer wastes, such as automotive tire rubber, are a source of long-term environmental pollution. This paper presents an approach to simplifying the rubber waste recycling process using cryogenic temperatures. The temperature of cryogenic treatment is ranged from 77 K to 280 K. Liquid nitrogen was used as a cryoagent for laboratory tests. Experimental and numerical studies have been carried out to determine the optimal conditions for the recycling process. Numerical studies were performed using the COMSOL Multiphysics cross-platform software. The optimal force of mechanical shock for the destruction of a tire which turned into a glassy state after cryoexposure was determined experimentally. The chemical and physical properties of the final product (crumb rubber) have been studied by scanning electron microscopy and energy dispersive X-ray spectroscopy. The analysis shows that the morphology and elemental composition of the samples remain practically unchanged, demonstrating environmental friendliness of the proposed process.
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Naddeo M, Viscusi G, Gorrasi G, Pappalardo D. Degradable Elastomers: Is There a Future in Tyre Compound Formulation? Molecules 2021; 26:4454. [PMID: 34361606 DOI: 10.3390/molecules26154454] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 07/14/2021] [Accepted: 07/19/2021] [Indexed: 11/16/2022] Open
Abstract
Problems related to non-biodegradable waste coming from vulcanized rubber represent one of the pre-eminent challenges for modern society. End-of-life tyres are an important source of this typology of waste and the increasingly high accumulation in the environment has contributed over the years to enhance land and water pollution. Moreover, the release into the environment of non-degradable micro-plastics and other chemicals as an effect of tyre abrasion is not negligible. Many solutions are currently applied to reuse end-of-life tyres as a raw material resource, such as pyrolysis, thermo-mechanical or chemical de-vulcanisation, and finally crumbing trough different technologies. An interesting approach to reduce the environmental impact of vulcanised rubber wastes is represented by the use of degradable thermoplastic elastomers (TPEs) in tyre compounds. In this thematic review, after a reviewing fossil fuel-based TPEs, an overview of the promising use of degradable TPEs in compound formulation for the tyre industry is presented. Specifically, after describing the properties of degradable elastomers that are favourable for tyres application in comparison to used ones, the real scenario and future perspectives related to the use of degradable polymers for new tyre compounds will be realized.
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Ahmadian Hoseini AH, Erfanian E, Kamkar M, Sundararaj U, Liu J, Arjmand M. Waste to Value-Added Product: Developing Electrically Conductive Nanocomposites Using a Non-Recyclable Plastic Waste Containing Vulcanized Rubber. Polymers (Basel) 2021; 13:polym13152427. [PMID: 34372031 PMCID: PMC8348210 DOI: 10.3390/polym13152427] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Revised: 07/19/2021] [Accepted: 07/20/2021] [Indexed: 11/16/2022] Open
Abstract
This study intends to show the potential application of a non-recyclable plastic waste towards the development of electrically conductive nanocomposites. Herein, the conductive nanofiller and binding matrix are carbon nanotubes (CNT) and polystyrene (PS), respectively, and the waste material is a plastic foam consisting of mainly vulcanized nitrile butadiene rubber and polyvinyl chloride (PVC). Two nanocomposite systems, i.e., PS/Waste/CNT and PS/CNT, with different compositions were melt-blended in a mixer and characterized for electrical properties. Higher electrical conduction and improved electromagnetic interference shielding performance in PS/Waste/CNT system indicated better conductive network of CNTs. For instance, at 1.0 wt.% CNT loading, the PS/Waste/CNT nanocomposites with the plastic waste content of 30 and 50 wt.% conducted electricity 3 and 4 orders of magnitude higher than the PS/CNT nanocomposite, respectively. More importantly, incorporation of the plastic waste (50 wt.%) reduced the electrical percolation threshold by 30% in comparison with the PS/CNT nanocomposite. The enhanced network of CNTs in PS/Waste/CNT samples was attributed to double percolation morphology, evidenced by optical images and rheological tests, caused by the excluded volume effect of the plastic waste. Indeed, due to its high content of vulcanized rubber, the plastic waste did not melt during the blending process. As a result, CNTs concentrated in the PS phase, forming a denser interconnected network in PS/Waste/CNT samples.
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Affiliation(s)
| | - Elnaz Erfanian
- Department of Chemical and Petroleum Engineering, University of Calgary, Calgary, AB T2N 1N4, Canada; (E.E.); (U.S.)
| | - Milad Kamkar
- School of Engineering, University of British Columbia, Kelowna, BC V1V 1V7, Canada; (A.H.A.H.); (M.K.)
| | - Uttandaraman Sundararaj
- Department of Chemical and Petroleum Engineering, University of Calgary, Calgary, AB T2N 1N4, Canada; (E.E.); (U.S.)
| | - Jian Liu
- School of Engineering, University of British Columbia, Kelowna, BC V1V 1V7, Canada; (A.H.A.H.); (M.K.)
- Correspondence: (J.L.); (M.A.)
| | - Mohammad Arjmand
- School of Engineering, University of British Columbia, Kelowna, BC V1V 1V7, Canada; (A.H.A.H.); (M.K.)
- Correspondence: (J.L.); (M.A.)
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Araujo-Morera J, Verdejo R, López-Manchado MA, Hernández Santana M. Sustainable mobility: The route of tires through the circular economy model. Waste Manag 2021; 126:309-322. [PMID: 33794443 DOI: 10.1016/j.wasman.2021.03.025] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 03/06/2021] [Accepted: 03/15/2021] [Indexed: 06/12/2023]
Abstract
Until nowadays, the concept of the 3Rs (Reduce, Reuse, Recycle) has tried to develop responsible consumption habits. Nonetheless, the rise of ecological thinking has generated the appearance of four new Rs in addition to these basic 3Rs; the currently 7Rs (Reduce, Reuse, Recycle, Redesign, Renew, Repair and Recover) which refer to the actions necessary to achieve the change towards a circular economy (CE) model. This model aims at extending the lifetime of the resources through their rational and efficient use to generate value repeatedly, reducing costs and waste. In this review, we examine the route followed by tires from the CE perspective, analyzing end-of-life strategies that aim to improve the circular flow of tire rubber materials. We discuss the most relevant studies on the "7Rs" concepts applied to tires, comparing different scientific approaches, as well as their industrial and commercial implementation. We also illustrate the drawbacks and feasibility of each of the R-hierarchy strategies. From the early stages of production to the post-consumption step, the path that tires trail within this CE model evidences the commitment and efforts towards the development of effective management schemes for achieving a real sustainable mobility.
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Affiliation(s)
- Javier Araujo-Morera
- Institute of Polymer Science and Technology ICTP-CSIC, Juan de la Cierva 3, Madrid 28006, Spain
| | - Raquel Verdejo
- Institute of Polymer Science and Technology ICTP-CSIC, Juan de la Cierva 3, Madrid 28006, Spain.
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van Hoek H, Noordermeer J, Heideman G, Blume A, Dierkes W. Best Practice for De-Vulcanization of Waste Passenger Car Tire Rubber Granulate Using 2-2 '-dibenzamidodiphenyldisulfide as De-Vulcanization Agent in a Twin-Screw Extruder. Polymers (Basel) 2021; 13:1139. [PMID: 33918356 DOI: 10.3390/polym13071139] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 03/26/2021] [Accepted: 03/28/2021] [Indexed: 01/25/2023] Open
Abstract
De-vulcanization of rubber has been shown to be a viable process to reuse this valuable material. The purpose of the de-vulcanization is to release the crosslinked nature of the highly elastic tire rubber granulate. For present day passenger car tires containing the synthetic rubbers Styrene-Butadiene Rubber (SBR) and Butadiene Rubber (BR) and a high amount of silica as reinforcing filler, producing high quality devulcanizate is a major challenge. In previous research a thermo-chemical mechanical approach was developed, using a twin-screw extruder and diphenyldisulfide (DPDS) as de-vulcanization agent.The screw configuration was designed for low shear in order to protect the polymers from chain scission, or uncontrolled spontaneuous recombination which is the largest problem involved in de-vulcanization of passenger car tire rubber. Because of disadvantages of DPDS for commercial use, 2-2'-dibenzamidodiphenyldisulfide (DBD) was used in the present study. Due to its high melting point of 140 °C the twin-screw extruder process needed to be redesigned. Subsequent milling of the devulcanizate at 60 °C with a narrow gap-width between the mill rolls greatly improved the quality of the devulcanizate in terms of coherence and tensile properties after renewed vulcanization. As the composition of passenger car tire granulate is very complex, the usefulness of the Horikx-Verbruggen analysis as optimization parameter for the de-vulcanization process was limited. Instead, stress-strain properties of re-vulcanized de-vulcanizates were used. The capacity of the twin-screw extruder was limited by the required residence time, implying a low screw speed. A best tensile strength of 8 MPa at a strain at break of 160% of the unblended renewed vulcanizate was found under optimal conditions.
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Kosmela P, Olszewski A, Zedler Ł, Burger P, Formela K, Hejna A. Structural Changes and Their Implications in Foamed Flexible Polyurethane Composites Filled with Rapeseed Oil-Treated Ground Tire Rubber. J Compos Sci 2021; 5:90. [DOI: 10.3390/jcs5030090] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The utilization of post-consumer car tires is an essential issue from an ecological and economic point of view. One of the simplest and the least harmful methods is their material recycling resulting in ground tire rubber (GTR), which can be further applied as fillers for polymer-based composites. Nevertheless, insufficient interfacial interactions implicate the necessity of GTR modification before introduction into polymer matrices. In this study, we investigated the influence of rapeseed oil-assisted thermo-mechanical treatment of GTR using a reactive extrusion process on the processing, structure, and performance of flexible polyurethane/GTR composite foams. Applied modifications affected the processing of polyurethane systems. They caused a noticeable reduction in the average cell size of foams, which was attributed to the potential nucleating activity of solid particles and changes in surface tension caused by the presence of oil. Such an effect was especially pronounced for the waste rapeseed oil, which resulted in the highest content of closed cells. Structural changes caused by GTR modification implicated the enhancement of foams’ strength. Mechanical performance was significantly affected by the applied modifications due to the changes in glass transition temperature. Moreover, the incorporation of waste GTR particles into the polyurethane matrix noticeably improved its thermal stability.
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Marín-Genescà M, Mujal-Rosas R, García-Amorós J, Mudarra M, Ramis Juan X, Colom Fajula X. Study Analysis of Thermal, Dielectric, and Functional Characteristics of an Ethylene Polyethylene Diene Monomer Blended with End-of-Life Tire Microparticles Amounts. Polymers (Basel) 2021; 13:polym13040509. [PMID: 33567684 PMCID: PMC7915781 DOI: 10.3390/polym13040509] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 02/01/2021] [Accepted: 02/03/2021] [Indexed: 01/25/2023] Open
Abstract
The recycling and disposal of disused tires is a topic of great concern to today’s companies, researchers, and society in general. In this sense, our research aims to recycle end-of-life tires (GTRs) through the separation of the fraction of vulcanized rubber from the other compounds in order to later grind this fraction and separate it into lower particle sizes. Finally, we aim to incorporate these GTR particles as a filler of an ethylene-polyethylene-diene monomer (EPDM). The obtained composites with EPDM and GTR are tested (5%, 10%, 20%) comparing these values with neat EPDM as a control sample. Thermal tests such as differential calorimetry (DSC) and thermogravimetric analysis (TGA) as well as dielectric tests (DEA) are performed in order to characterize these materials and check their viability as dielectric or semiconductor, for industrial use. It is checked how the presence of GTR increases functional properties such as conductivity/permittivity. The influence of temperature (40 to 120 °C) and addition of GTR particles in electrical properties has also been analyzed. The dielectric behavior of these composites is fully characterized, analyzing the different types of relaxation with increasing frequency (10 mHz to 3 MHz), using the electric modulus, and Argand diagrams among other measures. The influence of GTR and temperature in the dielectric and thermal behavior of these materials has been analyzed, where CB of GTR creates interfacial polarization phenomena in the dielectric behavior of the composite and increases the permittivity (real and imaginary) as well as the conductivity. Finally, with these obtained properties, the possible application of EPDM/GTR composites as industrial dielectrics has been studied.
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Affiliation(s)
- Marc Marín-Genescà
- Mechanical Engineering Department, Escola Tècnica Superior d’Enginyeria Química, Rovira i Virgili University, 43007 Tarragona, Spain
- Correspondence: ; Tel.: +34-618-787-469
| | - Ramon Mujal-Rosas
- Electrical Engineering Department, Escola d’Enginyeria de Terrassa, Technical University of Catalonia, 08222 Terrassa, Spain;
| | - Jordi García-Amorós
- Electrical Engineering Department, Escola Tècnica Superior d’Enginyeria, Rovira i Virgili University, 43007 Tarragona, Spain;
| | - Miguel Mudarra
- Physics Department, Universitat Politècnica de Catalunya, 08222 Terrassa, Spain;
| | - Xavier Ramis Juan
- Machines and Thermal Motors Department, Universitat Politècnica de Catalunya, 08222 Terrassa, Spain;
| | - Xavier Colom Fajula
- Chemical Engineering Department, Escola d’Enginyeria de Terrassa, Technical University of Catalonia, 08222 Terrassa, Spain;
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Lapkovskis V, Mironovs V, Kasperovich A, Myadelets V, Goljandin D. Crumb Rubber as a Secondary Raw Material from Waste Rubber: A Short Review of End-Of-Life Mechanical Processing Methods. Recycling 2020; 5:32. [DOI: 10.3390/recycling5040032] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Despite technological developments, modern methods for the disposal of end-of-life tires most often involve either their incineration in cement kilns or the destruction of tires in special landfills, demonstrating a lack of sustainable recycling of this valuable material. The fundamental role of recycling is evident, and the development of high-efficiency processes represents a crucial priority for the European market. Therefore, the investigation of end-of-life rubber processing methods is of high importance for both manufacturers and recyclers of rubber materials. In this paper, we review existing methods for processing of end-of-life tires, in order to obtain rubber crumb, which can later be used in the production of new industrial rubber goods and composites. We consider processes for separating end-of-life tires into fractions (in terms of types of materials) using chemical, mechanochemical, and mechanical methods to process the materials of used tires, in order to obtain crumb rubber of various fractions and chemical reactivities.
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Abstract
Recycling and recovery of waste tires is a serious environmental problem since vulcanized rubbers require several years to degrade naturally and remain for long periods of time in the environment. This is associated to a complex three dimensional (3D) crosslinked structure and the presence of a high number of different additives inside a tire formulation. Most end-of-life tires are discarded as waste in landfills taking space or incinerated for energy recovery, especially for highly degraded rubber wastes. All these options are no longer acceptable for the environment and circular economy. However, a great deal of progress has been made on the sustainability of waste tires via recycling as this material has high potential being a source of valuable raw materials. Extensive researches were performed on using these end-of-life tires as fillers in civil engineering applications (concrete and asphalt), as well as blending with polymeric matrices (thermoplastics, thermosets or virgin rubber). Several grinding technologies, such as ambient, wet or cryogenic processes, are widely used for downsizing waste tires and converting them into ground tire rubber (GTR) with a larger specific surface area. Here, a focus is made on the use of GTR as a partial replacement in virgin rubber compounds. The paper also presents a review of the possible physical and chemical surface treatments to improve the GTR adhesion and interaction with different matrices, including rubber regeneration processes such as thermomechanical, microwave, ultrasonic and thermochemical producing regenerated tire rubber (RTR). This review also includes a detailed discussion on the effect of GTR/RTR particle size, concentration and crosslinking level on the curing, rheological, mechanical, aging, thermal, dynamic mechanical and swelling properties of rubber compounds. Finally, a conclusion on the current situation is provided with openings for future works.
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Tobajas R, Elduque D, Ibarz E, Javierre C, Gracia L. A New Multiparameter Model for Multiaxial Fatigue Life Prediction of Rubber Materials. Polymers (Basel) 2020; 12:polym12051194. [PMID: 32456238 PMCID: PMC7285379 DOI: 10.3390/polym12051194] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 05/20/2020] [Accepted: 05/21/2020] [Indexed: 11/16/2022] Open
Abstract
Most of the mechanical components manufactured in rubber materials experience fluctuating loads, which cause material fatigue, significantly reducing their life. Different models have been used to approach this problem. However, most of them just provide life prediction only valid for each of the specific studied material and type of specimen used for the experimental testing. This work focuses on the development of a new generalized model of multiaxial fatigue for rubber materials, introducing a multiparameter variable to improve fatigue life prediction by considering simultaneously relevant information concerning stresses, strains, and strain energies. The model is verified through its correlation with several published fatigue tests for different rubber materials. The proposed model has been compared with more than 20 different parameters used in the specialized literature, calculating the value of the R2 coefficient by comparing the predicted values of every model, with the experimental ones. The obtained results show a significant improvement in the fatigue life prediction. The proposed model does not aim to be a universal and definitive approach for elastomer fatigue, but it provides a reliable general tool that can be used for processing data obtained from experimental tests carried out under different conditions.
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Affiliation(s)
- Rafael Tobajas
- Department of Mechanical Engineering, University of Zaragoza, C/María de Luna, 3, 50018 Zaragoza, Spain
- Correspondence: ; Tel.: + 34-876555211
| | - Daniel Elduque
- i+aitiip, Department of Mechanical Engineering, University of Zaragoza, C/María de Luna, 3, 50018 Zaragoza, Spain; (D.E.); (C.J.)
| | - Elena Ibarz
- i3A, Department of Mechanical Engineering, University of Zaragoza, C/María de Luna, 3, 50018 Zaragoza, Spain; (E.I.); (L.G.)
| | - Carlos Javierre
- i+aitiip, Department of Mechanical Engineering, University of Zaragoza, C/María de Luna, 3, 50018 Zaragoza, Spain; (D.E.); (C.J.)
| | - Luis Gracia
- i3A, Department of Mechanical Engineering, University of Zaragoza, C/María de Luna, 3, 50018 Zaragoza, Spain; (E.I.); (L.G.)
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