Abstract In this study, carbon fibers inserted into an epoxy resin derived from diglycidyl ether of bisphenol-A (DGEBA) were recovered based on the complete removal of the matrix by thermal treatment. The degradation of the composite was carried out at various experimental conditions and the ideal one was obtained at 450 °C for 2 h. Under this condition, all of the resin was removed without degrading the C fibers to any significant degree. The results of thermogravimetric analysis revealed several stages of thermal decomposition depending on the material analyzed. It was established by thermogravimetry analyses that the epoxy matrix starts to experience intense degradation at temperatures above 280 °C with maximum loss in the temperature range of 360–410 °C. In the case of composite samples above 800 °C a residue of approximately 50% by weight can be observed, which is related to carbon fibers. Confirmation of the removal of the resin from the carbon fiber was obtained by means of scanning electron microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). The kinetic of release of CH 4 , CO 2 and N 2 O gases during degradation process was accompanied by gas chromatography. The concentrations of methane and carbon dioxide increased significantly during the first 10 min of the processing and after this, no released quantities were verified. On the other hand N 2 O continues to be released even after 3 h of the process of burning the composite in air atmosphere. The treatment proposed in this study can be considered to be a low-cost one as well as being interesting for the recovery of C fibers present in DGEBA matrix which would normally be discarded after use.
Abstract Present study concerns to the thermal degradation of two carbon fibre/epoxy composites, which differ by their volume fractions in carbon fibre (56 and 59 vol%), investigated in cone calorimeter (under atmospheric condition with a piloted ignition). In order to study the influence of the carbon fibre amount on the composite thermal decomposition, the cone calorimeter external heat flux was varied up to 75 kW m−2. Thus, main parameters of the thermal decomposition of two different composi...
Bioethanol from sugarcane is becoming an increasingly important alternative energy source worldwide as it is considered to be both economically and environmentally sustainable. Besides being produced from a tropical perennial grass with high photosynthetic efficiency, sugarcane ethanol is commonly associated with low N fertilizer use because sugarcane from Brazil, the world's largest sugarcane producer, has a low N demand. In recent years, several models have predicted that the use of sugarcane ...
#1Yan Liu(CAS: Chinese Academy of Sciences)H-Index: 1
#2Jie Liu(CAS: Chinese Academy of Sciences)H-Index: 135
Last. Tao Tang(CAS: Chinese Academy of Sciences)H-Index: 15
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The combination of phenol and potassium hydroxide (KOH) was used to chemically recycle carbon fibre reinforced epoxy resin cured with 4,4′-diaminodiphenylmethane in subcritical water. This combination had a synergistic effect on decomposing this kind of epoxy resin. The main decomposition products from the epoxy resin were identified by means of GC–MS, and a possible free-radical reaction mechanism for the decomposition of epoxy resin is proposed. The recovered carbon fibres were characterized u...
Last. Hans de Wit(TU Delft: Delft University of Technology)H-Index: 5
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Abstract Composite materials are used in a wide range of applications such as automotive, aerospace and renewable energy industries. But they have not been properly recycled, due to their inherent nature of heterogeneity, in particular for the thermoset-based polymer composites. The current and future waste management and environmental legislations require all engineering materials to be properly recovered and recycled, from end-of-life (EOL) products such as automobiles, wind turbines and aircr...
Both environmental and economic factors have driven the development of recycling routes for the increasing amount of carbon fibre reinforced polymer (CFRP) waste generated. This paper presents a review of the current status and outlook of CFRP recycling operations, focusing on state-of-the-art fibre reclamation and re-manufacturing processes, and on the commercialisation and potential applications of recycled products. It is shown that several recycling and re-manufacturing processes are reachin...
#1Yongping Bai(HIT: Harbin Institute of Technology)H-Index: 2
#2Zhi Wang(HIT: Harbin Institute of Technology)H-Index: 9
Last. Liqun Feng(HIT: Harbin Institute of Technology)H-Index: 2
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The carbon fibers in carbon fibers reinforced epoxy resin composites were recovered in oxygen in supercritical water at 30 ± 1 MPa and 440 ± 10 °C. The microstructure of the recovered carbon fibers was observed using scanning electron microscopy (SEM) and atom force microscopy (AFM). The results revealed that the clean carbon fibers were recovered and had higher tensile strength relative to the virgin carbon fibers when the decomposition rate was above 85 wt.%, although the recovered carbon fibe...
#1Samuel Meure(CSIRO: Commonwealth Scientific and Industrial Research Organisation)H-Index: 3
#2Dong Yang Wu(CSIRO: Commonwealth Scientific and Industrial Research Organisation)H-Index: 18
Last. Scott A. Furman(CSIRO: Commonwealth Scientific and Industrial Research Organisation)H-Index: 24
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Abstract The aim of this study is to identify the chemical reactions/interactions that contribute to the interfacial strength development between a polyethylene-co-methacrylic acid (EMAA) healing agent and a mendable epoxy resin. Interfacial strength development during curing and healing are critical to the successful incorporation of healing characteristics into this new type of mendable resin. Fourier transform infrared spectroscopy (FTIR) has been used to monitor changes in the surface functi...
Hexaglycidyl cyclotriphosphazene (HGCP) was synthesized, and characterized by FTIR, 31P, 1H, and 13C-NMR. This compound was used as a reactive flame retardant to blend with commercial epoxy resin DGEBA (Diglycidyl ether of bisphenol A). Its effect on the DGEBA decomposition pathways was characterized by studying both gas and solid phases produced during thermogravimetric analysis (TGA). The gases evolved during TGA in air were studied by means of thermogravimetry coupled with Fourier transform i...
#1Liu Yuyan(HIT: Harbin Institute of Technology)H-Index: 3
#2Shan Guohua(HIT: Harbin Institute of Technology)H-Index: 1
Last. Meng Linghui(HIT: Harbin Institute of Technology)H-Index: 5
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Abstract In this paper, a method of chemical recycling of thermosetting epoxy composite was discussed. Water was used to be reaction medium and the decomposition of carbon fibre reinforced epoxy composites was studied. Experiments were devised in order to identify the significant process parameters that affect fibre reinforced composite recovery potential including temperature, time, catalyst, feedstock, and pressure. Experiments were performed in a batch-type reactor without stirring. Under the...
Carbon fiber reinforced composites (CFRC) have been used in aeronautical industry in the manufacture of different aircraft components that must attend tight mechanical requirements. This paper shows a study involving mechanical (flexural, shear, tensile and compressive tests) and morphological characterizations of four different laminates based on 2 epoxy resin systems (8552TM and F584TM) and 2 carbon fiber fabric reinforcements (Plain Weave (PW) and Eight Harness Satin (8HS)). All laminates wer...
Abstract Recyclable thermosets and thermoset composites with covalent adaptable networks (CANs, or dynamic covalent networks) have attracted considerable attention in recent years due to the combined merits of excellent mechanical and thermal properties, and chemical stabilities of traditional thermosets and recyclable, remoldable, and reprocessable attributes of thermoplastics. In this paper, we present an overview of the current strategies for synthesizing recyclable thermosets based on CANs, ...
Abstract The use of polymeric composite on transport applications as reinforcement material has been increased due to the low fuel consumption when replacing heavier materials. It is estimated that 170,000 tons of polymeric composites will be discarded by 2025, and recycling processing for carbon fibers recovery is required to save primary energy and reduce waste. Among the current techniques, pyrolysis processing has been most effective. On the other hand, innovation must maintain the structure...
Recently, significant events took place that added immensely to the sociotechnical pressure for developing sustainable composite recycling solutions, namely (1) a ban on composite landfilling in Germany in 2009, (2) the first major wave of composite wind turbines reaching their End-of-Life (EoL) and being decommissioned in 2019–2020, (3) the acceleration of aircraft decommissioning due to the COVID-19 pandemic, and (4) the increase of composites in mass production cars, thanks to the development...
Manufacturing-based carbon fibre-reinforced polymer (CFRP) and glass fibre-reinforced polymer (GFRP) wastes (pre-consumer waste) were recycled to recover valuable carbon fibres (CFs) and glass fibres (GFs), utilising a novel thermal recycling process with a cone calorimeter setup. The ideal conditions to recycle both the fibres occurred at 550 °C in atmospheric pressure. The processing time in the batch reactor to recycle CFs was 20–25 min, and to recycle GFs it was 25–30 min. The recovery rate ...
The results of studies on the recovery of carbon fibers by the method of low-temperature solvolysis from prepreg and reinforced plastics based on it are reported. The surface of carbon fibers extracted from prepreg and carbon fiber reinforced plastics (CFRPs) was characterized using scanning electron microscopy, thermal analysis, Fourier transform infrared spectroscopy, and Raman spectroscopy to understand their thermal stability characteristics, possible surface chemical composition, and the pr...
The growing use of carbon and glass fibres has increased awareness about their waste disposal methods. Tonnes of composite waste containing valuable carbon fibres and glass fibres have been cumulating every year from various applications. These composite wastes must be cost-effectively recycled without causing negative environmental impact. This review article presents an overview of the existing methods to recycle the cumulating composite wastes containing carbon fibre and glass fibre, with emp...
Last. Fa Luo(NPU: Northwestern Polytechnical University)H-Index: 34
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Microwave absorbing patches are used in a wide range of applications including mobile devices, digital devices and electronic products. Here, we used flake carbonyl iron (FCI) and chopped carbon fibers (CF) as double absorbers to fabricate thin microwave absorbing patches by tape-casting method. FCI and CF were oriented in polyurethane-modified epoxy resin (PMER) matrix, resulting in strong anisotropy of the microstructure. The effects of CF content (from 0 to 0.3 wt%) on thermal stability, elec...
#2Jimi Tjong(U of T: University of Toronto)H-Index: 19
Last. Mohini Sain(Huada: Beijing University of Chemical Technology)H-Index: 67
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Abstract Research results revealed that controlled thermal re-exposure of preconsumed recycled carbon fiber (RCF) increases the formation of a graphitic core and consequently a higher modulus recycled carbon fiber. Furthermore, formation of acidic functionality on carbon during thermal treatment led to improved adhesion with plastic. Transportation lightweighting is shaping the future of mobility and becomes focus of many original equipment manufacturers (OEMs) for many segments as an answer for...