Engineering › Mechanical Engineering

Fiber-reinforced polymer composites

Works Count: 39445

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Description

This cluster of papers focuses on the recycling technologies, methods, and environmental impact assessment of carbon fiber composites. It covers topics such as heat treatment, interfacial properties, mechanical and thermal behavior, as well as the use of graphene oxide and pyrolysis in the recycling process.

Keywords

Carbon Fiber; Recycling; Composite Materials; Polymer Composites; Interfacial Properties; Thermal Treatment; Graphene Oxide; Mechanical Properties; Environmental Impact; Pyrolysis

Carbon Materials for Advanced Technologies

1999-01-01

T.D. Burchell

A reconsideration of the relationship between the crystallite size La of carbons determined by X-ray diffraction and Raman spectroscopy

2006-08-15

Gerald A. Zickler , Bernd Smarsly , Notburga Gierlinger +2 more

Theory of multiple fracture of fibrous composites

1973-03-01

J. Aveston , Anthony E. Kelly

Growth, Structure, and Properties of Graphite Whiskers

1960-02-01

Roger Bacon

Graphite whiskers have been grown in a dc arc under a pressure of 92 atmospheres of argon and at 3900°K. They are embedded in a solid matrix of graphite which … Graphite whiskers have been grown in a dc arc under a pressure of 92 atmospheres of argon and at 3900°K. They are embedded in a solid matrix of graphite which builds up by diffusion of carbon vapor from the positive to the negative electrode. Diameters range from a fraction of a micron to over five microns, with recoverable lengths up to 3 cm. They consist of one or more concentric tubes, each tube being in the form of a scroll, or rolled-up sheet of graphite layers, extending continuously along the length of the whisker, with the c axis exactly perpendicular to the whisker axis. They exhibit a high degree of flexibility, tensile strengths up to 2000 kg-mm−2, Young's modulus in excess of 7×1012 dyne-cm−2, and values of room-temperature resistivity of around 65 μohm-cm, which approximates the single crystal value.

Recycling of composite materials

2011-10-24

Yongxiang Yang , R. Boom , Brijan Irion +3 more

Carbonization and graphitization

1984-01-01

A. Oberlin

Recycling technologies for thermoset composite materials—current status

2005-07-13

S. Pickering

Mechanical and thermal properties of graphite platelet/epoxy composites

2004-11-01

Asma Yasmin , Isaac M. Daniel

Structure of Graphite Oxide Revisited

1998-05-13

A. Lerf , Heyong He , Michael Förster +1 more

Graphite oxide (GO) and its derivatives have been studied using 13C and 1H NMR. NMR spectra of GO derivatives confirm the assignment of the 70 ppm line to C−OH groups … Graphite oxide (GO) and its derivatives have been studied using 13C and 1H NMR. NMR spectra of GO derivatives confirm the assignment of the 70 ppm line to C−OH groups and allow us to propose a new structural model for GO. Thus we assign the 60 ppm line to epoxide groups (1,2-ethers) and not to 1,3-ethers, as suggested earlier, and the 130 ppm line to aromatic entities and conjugated double bonds. GO contains two kinds of regions: aromatic regions with unoxidized benzene rings and regions with aliphatic six-membered rings. The relative size of the two regions depends on the degree of oxidation. The carbon grid is nearly flat; only the carbons attached to OH groups have a slightly distorted tetrahedral configuration, resulting in some wrinkling of the layers. The formation of phenol (or aromatic diol) groups during deoxygenation indicates that the epoxide and the C−OH groups are very close to one another. The distribution of functional groups in every oxidized aromatic ring need not be identical, and both the oxidized rings and aromatic entities are distributed randomly.

Recycling carbon fibre reinforced polymers for structural applications: Technology review and market outlook

2010-10-26

Soraia Pimenta , S.T. Pinho

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A review of heat treatment on polyacrylonitrile fiber

2007-04-15

Muhammad Syukri Abd Rahaman , Ahmad Fauzi Ismail , Azeman Mustafa

Recent advances in fiber/matrix interphase engineering for polymer composites

2015-04-09

J. Karger‐Kocsis , Haroon Mahmood , Alessandro Pegoretti

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Elastic properties of hydrogenated graphene

2010-12-09

Emiliano Cadelano , Pier Luca Palla , Stefano Giordano +1 more

There exist three conformers of hydrogenated graphene, referred to as chair-, boat-, or washboard-graphane. These systems have a perfect two-dimensional periodicity mapped onto the graphene scaffold but they are characterized … There exist three conformers of hydrogenated graphene, referred to as chair-, boat-, or washboard-graphane. These systems have a perfect two-dimensional periodicity mapped onto the graphene scaffold but they are characterized by a $s{p}^{3}$ orbital hybridization, have different crystal symmetry, and otherwise behave upon loading. By first-principles calculations we determine their structural and phonon properties, as well as we establish their relative stability. Through continuum elasticity we define a simulation protocol addressed to measure by a computer experiment their linear and nonlinear elastic moduli and we actually compute them by first principles. We argue that all graphane conformers respond to any arbitrarily oriented extension with a much smaller lateral contraction than the one calculated for graphene. Furthermore, we provide evidence that boat-graphane has a small and negative Poisson ratio along the armchair and zigzag principal directions of the carbon honeycomb lattice (axially auxetic elastic behavior). Moreover, we show that chair-graphane admits both softening and hardening hyperelasticity, depending on the direction of applied load.

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Kinetic concept of the strength of solids

1984-12-01

S. N. Zhurkov

The effect of processing on the structure and properties of carbon fibers

1998-01-01

D.D. Edie

Current status of recycling of fibre reinforced polymers: Review of technologies, reuse and resulting properties

2015-03-14

Géraldine Oliveux , Luke O. Dandy , Gary A. Leeke

A complete review of the different techniques that have been developed to recycle fibre reinforced polymers is presented. The review also focuses on the reuse of valuable products recovered by … A complete review of the different techniques that have been developed to recycle fibre reinforced polymers is presented. The review also focuses on the reuse of valuable products recovered by different techniques, in particular the way that fibres have been reincorporated into new materials or applications and the main technological issues encountered. Recycled glass fibres can replace small amounts of virgin fibres in products but not at high enough concentrations to make their recycling economically and environmentally viable, if for example, thermolysis or solvolysis is used. Reclaimed carbon fibres from high-technology applications cannot be reincorporated in the same applications from which they were recovered, so new appropriate applications have to be developed in order to reuse the fibres. Materials incorporating recycled fibres exhibit specific mechanical properties because of the particular characteristics imparted by the fibres. The development of specific standards is therefore necessary, as well as efforts in the development of solutions that enable reusers to benefit from their reinforcement potential. The recovery and reuse of valuable products from resins are also considered, but also the development of recyclable thermoset resins. Finally, the economic and environmental aspects of recycling composite materials, based on Life Cycle Assessment, are discussed.

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Polyacrylonitrile-based nanofibers—A state-of-the-art review

2011-07-23

S.K. Nataraj , Kap Seung Yang , Tejraj M. Aminabhavi

The future of carbon-carbon composites

1987-01-01

E. Fitzer

Grafting of epoxy chains onto graphene oxide for epoxy composites with improved mechanical and thermal properties

2013-12-21

Yan-Jun Wan , Long‐Cheng Tang , Li-Xiu Gong +5 more

Recent advances in low‐cost carbon fiber manufacture from lignin

2013-04-26

D. A. Baker , Timothy G. Rials

ABSTRACT The confluence of two US energy policy mandates, the 2012 Corporate Average Fuel Economy Standards and Renewable Fuels Standard #2, provide the opportunity to examine the possibility of high‐value … ABSTRACT The confluence of two US energy policy mandates, the 2012 Corporate Average Fuel Economy Standards and Renewable Fuels Standard #2, provide the opportunity to examine the possibility of high‐value materials from lignin with increased depth. In this case, the desire to provide lighter, low‐cost materials for automobiles to reduce fuel consumption, and to improve the economics of biorefineries for fuel production, have led to an increased interest in low‐cost carbon fiber manufacture from lignin. For this review the authors provide the context of subject matter importance, a cost comparison of potential low‐cost carbon fibers, a brief review of historical work, a review of more recent work, and a limited technical discussion followed by recommendations for future directions. As the available material for review is limited, the author includes many references to publicly available government documents and reviewed proceedings that are generally difficult to locate. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 713‐728, 2013

Carbon Fibers: Precursor Systems, Processing, Structure, and Properties

2014-03-25

Erik Frank , Lisa M. Steudle , Denis Ingildeev +2 more

This Review gives an overview of precursor systems, their processing, and the final precursor-dependent structure of carbon fibers (CFs) including new developments in precursor systems for low-cost CFs. The following … This Review gives an overview of precursor systems, their processing, and the final precursor-dependent structure of carbon fibers (CFs) including new developments in precursor systems for low-cost CFs. The following CF precursor systems are discussed: poly(acrylonitrile)-based copolymers, pitch, cellulose, lignin, poly(ethylene), and new synthetic polymeric precursors for high-end CFs. In addition, structure-property relationships and the different models for describing both the structure and morphology of CFs will be presented.

Carbon fiber surfaces and composite interphases

2014-07-17

Mohit Sharma , Shanglin Gao , Edith Mäder +3 more

Superconductivity in Graphitic Compounds

1965-02-15

N. B. Hannay , T. H. Geballe , B. T. Matthias +3 more

Received 20 January 1965DOI:https://doi.org/10.1103/PhysRevLett.14.225©1965 American Physical Society Received 20 January 1965DOI:https://doi.org/10.1103/PhysRevLett.14.225©1965 American Physical Society

A new structural model for graphite oxide

1998-04-01

Heyong He , Jacek Klinowski , Michael Förster +1 more

A microbond method for determination of the shear strength of a fiber/resin interface

1987-01-01

Bernard Miller , Pierre Muri , Ludwig Rebenfeld

The formation of graphitizing carbons from the liquid phase

1965-10-01

JD Brooks , G.H. Taylor

Interfacial Microstructure and Properties of Carbon Fiber Composites Modified with Graphene Oxide

2012-03-06

Xiaoqing Zhang , Xinyu Fan , Chun Yan +4 more

The performance of carbon fiber-reinforced composites is dependent to a great extent on the properties of fiber–matrix interface. To improve the interfacial properties in carbon fiber/epoxy composites, we directly introduced … The performance of carbon fiber-reinforced composites is dependent to a great extent on the properties of fiber–matrix interface. To improve the interfacial properties in carbon fiber/epoxy composites, we directly introduced graphene oxide (GO) sheets dispersed in the fiber sizing onto the surface of individual carbon fibers. The applied graphite oxide, which could be exfoliated to single-layer GO sheets, was verified by atomic force microscope (AFM). The surface topography of modified carbon fibers and the distribution of GO sheets in the interfacial region of carbon fibers were detected by scanning electron microscopy (SEM). The interfacial properties between carbon fiber and matrix were investigated by microbond test and three-point short beam shear test. The tensile properties of unidirectional (UD) composites were investigated in accordance with ASTM standards. The results of the tests reveal an improved interfacial and tensile properties in GO-modified carbon fiber composites. Furthermore, significant enhancement of interfacial shear strength (IFSS), interlaminar shear strength (ILSS), and tensile properties was achieved in the composites when only 5 wt % of GO sheets introduced in the fiber sizing. This means that an alternative method for improving the interfacial and tensile properties of carbon fiber composites by controlling the fiber–matrix interface was developed. Such multiscale reinforced composites show great potential with their improved mechanical performance to be likely applied in the aerospace and automotive industries.

Role of acid-base interfacial bonding in adhesion

1987-01-01

Frederick M. Fowkes

The strength of macroscopic adhesive bonds of polymers is known to be directly proportional to the microscopic exothermic interfacial energy changes of bond formation, as measured by Dupre's 'work of … The strength of macroscopic adhesive bonds of polymers is known to be directly proportional to the microscopic exothermic interfacial energy changes of bond formation, as measured by Dupre's 'work of adhesion'. Since the work of adhesion can be very appreciably increased by interfacial acid-base bonding with concomitant increases in adhesive bond strength, it is important to understand the acid-base character of polymers and of the surface sites of substrates or of the reinforcing fillers of polymer composites. The best known acid-base bonds are the hydrogen bonds; these are typical of acid-base bonds, with interaction energies dependent on the acidity of the hydrogen donor and on the basicity of the hydrogen acceptor. The strengths of the acidic or basic sites of polymers and of inorganic substrates can be easily determined by spectroscopic or calorimetric methods, and from this information one can start to predict the strengths of adhesive bonds. An important application of the new knowledge of interfacial acid-base bonding is the predictable enhancement of interfacial bonding accomplished by surface modification of inorganic surfaces to enhance the interfacial acid-base interactions.

The structure of graphitic carbons

1951-05-01

Rosalind Franklin

Crystal Structures of Three Crystalline Forms of Poly(vinylidene fluoride)

1972-09-01

Ryozo Hasegawa , Yasuhiro Takahashi , Yôzô Chatani +1 more

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Tensile properties of short-glass-fiber- and short-carbon-fiber-reinforced polypropylene composites

2000-10-01

Shao‐Yun Fu , Bernd Lauke , Edith Mäder +2 more

Infrared Spectra of Poly(acetylene)

1971-03-01

Hideki Shirakawa , Sakuji Ikeda

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Hygrothermal effects of epoxy resin. Part I: the nature of water in epoxy

1999-09-01

Jiming Zhou , James P. Lucas

Adhesion of Graphite Fibers to Epoxy Matrices: I. The Role of Fiber Surface Treatment

1983-07-01

Lawrence T. Drzal , Michael J. Rich , Pamela F. Lloyd

Abstract Adhesion between graphite fibers and epoxy matrices is a necessary and sometimes controlling factor in achieving optimum performance. Manufacturers′ proprietary fiber surface treatments promote adhesion without providing a basic … Abstract Adhesion between graphite fibers and epoxy matrices is a necessary and sometimes controlling factor in achieving optimum performance. Manufacturers′ proprietary fiber surface treatments promote adhesion without providing a basic understanding of the fiber surface properties altered through their use. This study has combined fiber surface chemistry, morphology, interfacial strength measurements and fracture characterization in order to elucidate the role of surface treatments. The results of this investigation lead to the conclusion that surface treatments designed to promote adhesion to epoxy matrix materials operate through a two-part mechanism. First, the treatments remove a weak outer fiber layer initially present on the fiber. Second surface chemical groups are added which increase the interaction with the matrix. Increases in fiber surface area are not an important factor in promoting fiber-matrix adhesion. In some cases the upper limit to fiber-matrix interfacial shear strength is the intrinsic shear strength of the fiber itself.

Fabrication and Properties of Carbon Fibers

2009-12-16

Xiaosong Huang

This paper reviews the research and development activities conducted over the past few decades on carbon fibers. The two most important precursors in the carbon fiber industry are polyacrylonitrile (PAN) … This paper reviews the research and development activities conducted over the past few decades on carbon fibers. The two most important precursors in the carbon fiber industry are polyacrylonitrile (PAN) and mesophase pitch (MP). The structure and composition of the precursor affect the properties of the resultant carbon fibers significantly. Although the essential processes for carbon fiber production are similar, different precursors require different processing conditions in order to achieve improved performance. The research efforts on process optimization are discussed in this review. The review also attempts to cover the research on other precursor materials developed mainly for the purpose of cost reduction.

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Dispersions of Aramid Nanofibers: A New Nanoscale Building Block

2011-07-29

Y. Ming , Keqin Cao , Lang Sui +7 more

Stable dispersions of nanofibers are virtually unknown for synthetic polymers. They can complement analogous dispersions of inorganic components, such as nanoparticles, nanowires, nanosheets, etc. as a fundamental component of a … Stable dispersions of nanofibers are virtually unknown for synthetic polymers. They can complement analogous dispersions of inorganic components, such as nanoparticles, nanowires, nanosheets, etc. as a fundamental component of a toolset for design of nanostructures and metamaterials via numerous solvent-based processing methods. As such, strong flexible polymeric nanofibers are very desirable for the effective utilization within composites of nanoscale inorganic components such as nanowires, carbon nanotubes, graphene, and others. Here stable dispersions of uniform high-aspect-ratio aramid nanofibers (ANFs) with diameters between 3 and 30 nm and up to 10 μm in length were successfully obtained. Unlike the traditional approaches based on polymerization of monomers, they are made by controlled dissolution of standard macroscale form of the aramid polymer, that is, well-known Kevlar threads, and revealed distinct morphological features similar to carbon nanotubes. ANFs are successfully processed into films using layer-by-layer (LBL) assembly as one of the potential methods of preparation of composites from ANFs. The resultant films are transparent and highly temperature resilient. They also display enhanced mechanical characteristics making ANF films highly desirable as protective coatings, ultrastrong membranes, as well as building blocks of other high performance materials in place of or in combination with carbon nanotubes.

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The Role of the Interface in Carbon Fibre-Epoxy Composites

1987-09-01

J. Schultz , L. Lavielle , Christian A. Martin

Abstract The final performance of a composite material depends strongly on the quality of the fibre-matrix interface. The interactions developed at the interface were studied using the acid-base or acceptor-donor … Abstract The final performance of a composite material depends strongly on the quality of the fibre-matrix interface. The interactions developed at the interface were studied using the acid-base or acceptor-donor concept. The surface characteristics of the carbon fibres and the epoxy matrix were studied using a tensiometric method and the inverse gas chromatography technique. Acid-base surface characters could be determined allowing the interactions at the interface to be described by a specific interaction parameter. It was shown that the shear strength of the interface, as measured by a fragmentation test, is strongly correlated to this specific interaction parameter, demonstrating the importance of acid-base interactions in the fibre-matrix adhesion.

Repairable Woven Carbon Fiber Composites with Full Recyclability Enabled by Malleable Polyimine Networks

2016-02-15

Philip Taynton , Huagang Ni , Chengpu Zhu +5 more

Carbon-fiber reinforced composites are prepared using catalyst-free malleable polyimine networks as binders. An energy neutral closed-loop recycling process has been developed, enabling recovery of 100% of the imine components and … Carbon-fiber reinforced composites are prepared using catalyst-free malleable polyimine networks as binders. An energy neutral closed-loop recycling process has been developed, enabling recovery of 100% of the imine components and carbon fibers in their original form. Polyimine films made using >21% recycled content exhibit no loss of mechanical performance, therefore indicating all of the thermoset composite material can be recycled and reused for the same purpose. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Processing, structure, and properties of carbon fibers

2016-10-18

Bradley A. Newcomb

Recent advances in carbon-fiber-reinforced thermoplastic composites: A review

2017-12-16

Shanshan Yao , Fan‐Long Jin , Kyong Yop Rhee +2 more

Current status of carbon fibre and carbon fibre composites recycling

2020-04-09

Jin Zhang , Venkata S. Chevali , Hao Wang +1 more

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Carbon-Carbon Composites

1993-01-01

G. Savage

Kinetic Concept of the Strength of Solids

1965-12-01

S. N. Zhurkov

Recent advances of interphases in carbon fiber-reinforced polymer composites: A review

2022-01-19

Hao Zheng , Wenjian Zhang , Bowen Li +7 more

Carbon Fibers and Their Composites

2005-05-20

Peter Morgan

Most literature pertaining to carbon fibers is of a theoretical nature. Carbon Fibers and their Composites offers a comprehensive look at the specific manufacturing of carbon fibers and graphite fibers … Most literature pertaining to carbon fibers is of a theoretical nature. Carbon Fibers and their Composites offers a comprehensive look at the specific manufacturing of carbon fibers and graphite fibers into the growing surge of diverse applications that include flameproof materials, protective coatings, biomedical and prosthetics application

Graphite Fibers and Filaments

1988-01-01

M. S. Dresselhaus , G. Dresselhaus , Kō Sugihara +2 more

Vapor-grown carbon fibers (VGCFs)

2001-08-01

Morinobu Endo , Yoong Ahm Kim , T Hayashi +4 more

Acrylonitrile-Styrene-Acrylate Resin with Superior Low Temperature Toughness by Preparing a Core–Shell Phase Morphology of Two Rubbers through the Effect of Interfacial Tensions

2025-06-25

Jin Huang , Jun Hou , Yinqiao Zhao +2 more | Langmuir

The phase morphology of acrylate rubber (PBA) in acrylonitrile-styrene-acrylate (ASA) copolymer and silicone rubber was designed to be a core-shell structure in the acrylonitrile-styrene (AS) resin matrix by taking advantage … The phase morphology of acrylate rubber (PBA) in acrylonitrile-styrene-acrylate (ASA) copolymer and silicone rubber was designed to be a core-shell structure in the acrylonitrile-styrene (AS) resin matrix by taking advantage of their interfacial tension differences during blending with a twin-screw extruder. Prior to this, in order to enhance the compatibility with silicone in AS resin, we grafted AS to the silicone rubber nanoparticles, synthesizing a silicone-g-AS (SiAS) copolymer. The selective extraction test and SEM images verified the formation of the core-shell structure. This distinctive phase morphology, featuring a silicone core and an acrylate shell in SiAS/ASA/AS ternary blends, significantly improves their impact strength at -30 °C, 0 °C, and 25 °C. Notably, the impact strength of SiAS/ASA/AS (Si9A21) at -30 °C is five times that of the commercial product (Si0A30). The SEM images of the impact section indicate that introducing ductile silicone rubber into the interior of acrylate rubber microparticles can increase and refine the cavitation of the rubber layer upon impact. The TGA results indicate that SiAS considerably enhances the heat resistance of the ternary blends. The tensile and flexural properties of the SiAS/ASA/AS ternary blends demonstrate that the ternary blends do not lose their intrinsic physical properties.

Interface Design Strategy for Improving Interfacial Properties and Achieving Interfacial Self‐Healing Capabilities in Carbon Fiber Composites Based on the Introduction of <scp>ZIF8</scp> and Diels–Alder Adducts

2025-06-25

Weiyao Zhu , Lei Xiong , Yuke Li +1 more | Polymer Composites

ABSTRACT In this research article, the Diels–Alder (DA) cycloaddition adducts and zeolitic imidazolate framework 8 (ZIF8) were simultaneously introduced onto the carbon fiber (CF) surface to improve interface adhesions and … ABSTRACT In this research article, the Diels–Alder (DA) cycloaddition adducts and zeolitic imidazolate framework 8 (ZIF8) were simultaneously introduced onto the carbon fiber (CF) surface to improve interface adhesions and endow the CF/epoxy (EP) composite with interface self‐healing properties. Fourier transform infrared (FT‐IR) spectroscopy, X‐ray photoelectron spectroscopy (XPS), and other characterization techniques were carried out to verify the fabrication of carbon fiber grafted with ZIF8 and DA adducts (CF‐ZIF8‐DA). The introduced ZIF8 and DA adducts significantly ameliorated the surface roughness, active functional groups, wettability, and surface energy of CF. As a result, the interfacial and mechanical properties (interfacial shear, monofilament tensile, bending, and interlaminar shear strength) of the CF‐ZIF8‐DA/EP composite were dramatically increased by 90.2%, 7.8%, 22.1%, and 30.6% compared with the desized CF/EP composite, respectively. The micro‐droplet test verified that this surface modification process on CF could endow the designed composite with interface self‐healing properties through the reversible transformation of DA bonds. The first self‐healing efficiency of the CF‐ZIF8‐DA/EP composite was about 89.6%, while the composite still recovered with a relatively high self‐healing efficiency after five healing cycles. Furthermore, the interfacial self‐healing mechanisms were also explored in detail using FT‐IR spectroscopy. Thus, this novel strategy based on the introduction of ZIF8 and thermoreversible DA adducts will provide enormous potential in developing structural composites with high interface adhesion and excellent self‐healing performance.

Impact of Temperature and Residence Time on the Recovery of Isoprene through Pyrolysis of Polyisoprene Rubber

2025-06-24

Emmanuel Awosu , Yu Hirano , Shogo Kumagai +6 more | ACS Sustainable Resource Management

Glass Fibers Produced With Recovered Glass Fibers From Wind Turbine Blades—Recycling Value Chain and Properties of Glass Fibers and Composites

2025-06-24

Justine Beauson , Asger Bech Abrahamsen , Irene Bach Velling Villadsen +7 more | Polymer Composites

ABSTRACT Recycling wind turbine blades poses significant challenges due to their composition. Blades are primarily made of fiber‐reinforced composites with a thermoset polymer, and about 60% of their mass consists … ABSTRACT Recycling wind turbine blades poses significant challenges due to their composition. Blades are primarily made of fiber‐reinforced composites with a thermoset polymer, and about 60% of their mass consists of glass fibers. After recycling, recovered glass fibers typically exhibit poor properties, making them difficult to repurpose. This study explores the feasibility of remelting recovered glass fibers to produce new high‐performance glass fibers. Specifically, it investigates the potential of preparing a powder from recovered glass fibers and incorporating it into the production of new glass fibers. A large‐scale experiment was conducted, using glass fibers recovered from wind turbine blades at a concentration of 1.96 wt% to produce new high‐performance glass fibers. In total, 76 tons of glass fibers were produced, with properties comparable to those made from virgin materials. The study also examines the properties of composites manufactured with these new fibers and their potential application in new wind turbine blades. To date, no other studies have reported large‐scale experimental trials on remelting recovered glass fibers from end‐of‐life wind turbine blades to produce new glass fibers for manufacturing new wind turbine blades.

Interfacial effects of carbon nanotube-modified epoxy on PBO Fiber composites: Quasi-static and dynamic mechanical properties

2025-06-23

Hua Zhang , Yuchen Xie , Ping Wang +3 more | Progress in Organic Coatings

Enhancing the Interfacial Adhesion and Mechanical Strength of Pultruded ECR–Glass Fiber Composites with Nanofiller-Infused Epoxy Resin

2025-06-23

Poorna Chandra , Ravikumar Venkatarayappa , Savitha D. Chandrashekar +7 more | Journal of Composites Science

The effect of the interaction between silica (nS) and hydroxyapatite (nHap) nanomaterials on the characteristics of unidirectional glass-fiber-reinforced epoxy (GF/Ep) composite systems is investigated in this work. The goal of … The effect of the interaction between silica (nS) and hydroxyapatite (nHap) nanomaterials on the characteristics of unidirectional glass-fiber-reinforced epoxy (GF/Ep) composite systems is investigated in this work. The goal of the study is to use these nanofillers to improve the microstructure and mechanical characteristics. Pultrusion was used to produce hybrid nanocomposites while keeping the GF loading at a consistent 75% by weight. The hybrid nanocomposites were made with a total filler loading of 6 wt.%, including nHap, and a nS loading ranging from 2 to 4 wt.%. The mechanical performance of the composite was greatly improved by the use of these nanofillers. Compared to neat GF/Ep, hybrid nanocomposites with 6 wt.% combined fillers exhibited increased hardness (14%), tensile strength (25%), interlaminar shear strength (21.3%), and flexural strength (33%). These improvements are attributed to efficient filler dispersion, enhanced fiber-matrix adhesion, and crack propagation resistance. Incorporating 4 wt.% nS alone improved hardness (6%), tensile strength (9%), tensile modulus (21%), interlaminar shear strength (11.4%), flexural strength (12%), and flexural modulus (14%). FTIR analysis indicated Si-O-Si network formation and increased hydrogen bonding, supporting enhanced interfacial interactions. Ultraviolet reflectance measurements showed increased UV reflectivity with nS, especially in hybrid systems, due to synergistic effects. Impact strength also improved, with a notable 11.6% increase observed in the hybrid nanocomposite. Scanning and transmission electron microscopy confirmed that the nanofillers act as secondary reinforcements within the matrix. These hybrid nanocomposites present a promising material choice for various industries, including marine structural applications and automotive components.

Studies on Molecular Weight Distribution and Functional Properties of Oligo, Polymeric Carbosilanes in Pyrolysis Polycondensation of Polydimethylsilane

2025-06-23

G. Santhana Krishnan , Anil C. Keerthana , M. Shinan | Silicon

Verification and Optimization of the Strain Limits for Carbon Fiber Multifilament Tensile Modulus Calculation

2025-06-23

Shaoliang Li , Yan Zhao , Jianwen Bao | Polymer Composites

ABSTRACT Carbon fibers and their composites are widely used in aviation, aerospace, automotive, electronics, and other fields. In this work, morphological, chemical, wettability, and crystalline characterizations, as well as multifilament … ABSTRACT Carbon fibers and their composites are widely used in aviation, aerospace, automotive, electronics, and other fields. In this work, morphological, chemical, wettability, and crystalline characterizations, as well as multifilament tensile tests, are performed on CCF300, T300, CCF800H, T800H, CCF800S, and T800SC carbon fibers. The crystalline characteristics and multifilament tensile modulus of the carbon fibers are thoroughly studied. According to XRD, Raman, and TEM, T800‐grade carbon fibers (with grain sizes around 2.15 nm and I D /I G around 1.75) possess larger grains and a higher graphitization degree than T300‐grade carbon fibers (with grain sizes around 1.75 nm and I D /I G around 2.50). Subsequently, the multifilament tensile modulus calculated by different strain limits is compared with each other to reveal its changing rules. Combining the crystalline structure analysis and mechanical properties, the evolution model and relevant effects of the multifilament tensile process are summarized. Furthermore, regarding the structural and mechanical results implying that T800‐grade carbon fibers have longer linear elastic ranges, a new distinguishing method of the strain limits for multifilament tensile modulus calculation decided by the strain at failure of carbon fibers is proposed to optimize the measurement of multifilament tensile modulus of T800‐grade carbon fibers. The optimized calculating method increases the measured modulus of T800‐grade carbon fibers by around 7% while making it closer to the nominal modulus value from the producers.

Interfacial Strength in Hierarchical Carbon Fiber Composites: Interplay of Interphase Modulus and Roughness

2025-06-23

Nihal Kanbargi , Sumit Gupta , Sargun S. Rohewal +2 more | Advanced Materials Interfaces

Abstract A facile, direct deposition approach that exploits van der Waals interactions between carbonaceous materials is utilized to create unidirectional hybrid carbon fiber composites. Two small molecule crosslinkers, a trifunctional … Abstract A facile, direct deposition approach that exploits van der Waals interactions between carbonaceous materials is utilized to create unidirectional hybrid carbon fiber composites. Two small molecule crosslinkers, a trifunctional aromatic (TL) and a difunctional aliphatic (DL) acyl chloride, are first utilized to create a crosslinked interphase with a softer and stiffer modulus respectively. TL crosslinked interphase with a higher modulus improved the tensile strength by 50%, despite non‐covalent linking between fiber and matrix, elucidating the critical role of the interphase in alleviating modulus mismatch between the high modulus carbon fiber and the rubbery matrix. Fractional quantities of carbon nanotubes are additionally dispersed in the small molecule crosslinkers which behaved as a dispersant, helping introduce nanoasperities on the carbon fiber surface. Strong “pi‐pi” interactions between CNTs and CF contributed to tensile properties, which are increased by 66% compared to the control. A cohesive zone model suggests that a stiffer interphase is better able to exploit surface heterogeneities and roughness on the fiber, synergistically enhancing interfacial strength.

Development and Interfacial Mechanism of Epoxy Soybean Oil-Based Semi-Liquid Gel Materials for Wellbore Sealing Applications

2025-06-22

Yuexin Tian , Yintao Liu , Haifeng Dong +2 more | Gels

In this study, a novel semi-liquid gel material based on bisphenol A-type epoxy resin (E51), methylhexahydrophthalic anhydride (MHHPA), and epoxidized soybean oil (ESO) was developed for high-performance wellbore sealing. The … In this study, a novel semi-liquid gel material based on bisphenol A-type epoxy resin (E51), methylhexahydrophthalic anhydride (MHHPA), and epoxidized soybean oil (ESO) was developed for high-performance wellbore sealing. The gel system exhibits tunable gelation times ranging from 1 to 10 h (±0.5 h) and maintains a low viscosity of <100 ± 2 mPa·s at 25 °C, enabling efficient injection into the wellbore. The optimized formulation achieved a compressive strength exceeding 112.5 ± 3.1 MPa and a breakthrough pressure gradient of over 50 ± 2.8 MPa/m with only 0.9 PV dosage. Fourier transform infrared spectroscopy (FTIR) confirmed the formation of a dense, crosslinked polyester network. Interfacial adhesion was significantly enhanced by the incorporation of 0.25 wt% octadecyltrichlorosilane (OTS), yielding an adhesion layer thickness of 391.6 ± 12.7 nm—approximately 9.89 times higher than that of the unmodified system. Complete degradation was achieved within 48 ± 2 h at 120 °C using a γ-valerolactone and p-toluenesulfonic acid solution. These results demonstrate the material’s potential as a high-strength, injectable, and degradable sealing solution for complex subsurface environments.

Effects of Recycling on the Elevated Temperature Bending and Creep Response of Regenerated Glass Fiber Reinforced Epoxy Composites

2025-06-19

Rohith Gandi , S.C. Parida , Kishore Kumar Mahato +4 more | Polymer Composites

ABSTRACT The surging global demand for Glass Fiber Reinforced Polymer (GFRP) composites across various sectors has led to significant waste generation, necessitating efficient and sustainable recycling techniques. Though several studies … ABSTRACT The surging global demand for Glass Fiber Reinforced Polymer (GFRP) composites across various sectors has led to significant waste generation, necessitating efficient and sustainable recycling techniques. Though several studies have reported the mechanical performance of either recycled glass fibers or regenerated glass fiber epoxy composites (RGFECs) at ambient temperature, their mechanical behavior under elevated temperatures remains insufficiently investigated. This study evaluates the flexural and creep behavior of RGFECs across different temperatures. The recycled glass fiber (RGFs) fabrics were obtained after 6 cycles, each cycle consisting of an optimized 7.5 min microwave irradiation phase and cooling phase, in a peracetic acid medium. As anticipated, the flexural strength of virgin glass fiber epoxy composites (VGFECs) is higher than that of RGFECs by 13%, 10%, and 28% at 50°C, 70°C, and 100°C, respectively. Further, creep testing revealed a higher temperature sensitivity of RGFEC composites in comparison to VGFEC. When the testing temperature was increased from 50°C to 70°C, the instantaneous creep strain of VGFEC and RGFEC increased by ~11% and ~23%, respectively. Further increase from 70°C to 100°C showed a negligible effect on VGFEC, whereas for RGFEC, it was increased by ~44%. The steady‐state strain rate of RGFEC is higher than that of VGFEC by ~280% and ~305% at 50°C and 70°C, respectively. Topography and fractography were conducted to study the RGFs' surface morphology and flexural failure modes at elevated temperatures. This study underscores the necessity for further optimization of recycling techniques to produce durable RGFECs in thermally demanding applications.

Main Directions of Production Development and Strength Characteristics of Aramid Fibers in China, South Korea, and Russia in the 21ST Century. Review

2025-06-18

С. М. Шебанов , V. G. Bova , М. С. Шебанов +5 more | Fibre Chemistry

Quantification of the thermal expansion of carbon fibres in CFRP at low temperatures using X-ray diffraction

2025-06-18

Jiraphant Srisuriyachot , Wadwan Singhapong , Paloma Rodriguez Santana +5 more | Composites Part B Engineering

Carbon-fibre composites can be broken down into reusable components

2025-06-18

| Nature

Characterization of Unidirectional Aligned Discontinuous Fiber Reinforced Composites Containing a Toughened Epoxy Resin Produced Using the <scp>HiPerDiF</scp> Process

2025-06-17

Chantal Lewis , Karthik Ram Ramakrishnan , Marco L. Longana +5 more | Polymer Composites

ABSTRACT Aligned discontinuous fiber reinforced composites (ADFRC) offer promising applications due to their manufacturability and tailorable mechanical properties. In this study, the high performance discontinuous fiber (HiPerDiF) technology is used … ABSTRACT Aligned discontinuous fiber reinforced composites (ADFRC) offer promising applications due to their manufacturability and tailorable mechanical properties. In this study, the high performance discontinuous fiber (HiPerDiF) technology is used to produce ADFRC consisting of 3 and 6 mm long virgin carbon fibers and a highly toughened commercial epoxy resin (CYCOM 977–2). The HiPerDiF machine settings were optimized and the resultant physical and mechanical attributes systematically analyzed to show improvements in tensile performance and microstructure quality. There was an increase in stiffness by 3%, strength by 28% and failure strain by 26% compared to samples produced with initial machine settings. 73% of fibers were spatially aligned within 10° and 62% of fibers aligned in‐plane within 10°. ADFRC specimens with 6 mm fibers at 23% fiber volume fraction were optimally prepared to retain 32% of the stiffness, 30% of the strength and 57% of the failure strain in comparison with tested unidirectional continuous composite specimens containing similar constituent materials. This work has demonstrated the viability of producing aligned discontinuous fiber preform in high volume resulting in composites with improved tensile performance. With the upscaled HiPerDiF machine, improved mechanical performance can be achieved when the machine settings and fiber properties are optimized to maintain a high alignment and consistent areal weight.

The Ethylenediamine Surface Functionalization of TiO<sub>2</sub> on the Mechanical Properties of Carbon Fiber Filled PMMA Composite

2025-06-17

Zhaohong Xu , Jian Li | Surface and Interface Analysis

ABSTRACT To improve the stress transfer between PMMA and carbon fibers, ethylenediamine surface functionalization of TiO 2 were grown on carbon fibers to produce TiO 2 grown short carbon fibers. … ABSTRACT To improve the stress transfer between PMMA and carbon fibers, ethylenediamine surface functionalization of TiO 2 were grown on carbon fibers to produce TiO 2 grown short carbon fibers. The synergic reinforcing effects of combined fillers were analyzed on the fracture surface of composites through scanning electron microscopy (SEM). Mechanical characterization of composites was performed to investigate the synergy effects of TiO 2 and CF in the PMMA matrix. The multiscale composites revealed significant improvement in modulus, strength, as well as impact resistance in comparison to CF/PMMA composites. The optimum mechanical properties of CF/TiO 2 /PMMA composite were obtained when the TiO 2 content was 6 vol% for 15 vol% CF/PMMA composite.

Solidified, Stable Carbon

2025-06-17

| The MIT Press eBooks

Carbon Fibers Prepared by Isotropic Pitch with Different Subfraction Contents during Carbonization: Implications for Enhancing Mechanical Properties

2025-06-16

Luning Chai , Lou Bin , Jinshan Xu +7 more | Energy & Fuels

Molecular Dynamics Study on Quartz‐Indenter Shape and Depth Effects in Epoxy Interfacial Mechanics

2025-06-16

Pengchang Wei , Zhen‐Yu Yin , Pierre‐Yves Hicher +1 more | International Journal for Numerical and Analytical Methods in Geomechanics

ABSTRACT The interfacial mechanical behavior between epoxy and quartz at the microscale remains inadequately understood. The quartz‐indenter shape and indentation depth ( h c ) effect on epoxy interfacial mechanical … ABSTRACT The interfacial mechanical behavior between epoxy and quartz at the microscale remains inadequately understood. The quartz‐indenter shape and indentation depth ( h c ) effect on epoxy interfacial mechanical behavior has been investigated through molecular dynamics (MD) simulation of nanoindentation and nanoscratching. This work employs two Vickers‐type and four spherical indenters with varying radii ( R ) under different h c conditions, revealing the fundamental deformation mechanisms at the microscale. The reduced modulus and Young's modulus of epoxy resin obtained from MD simulations align well with experimental results. Key findings include: (1) during MD nanoindentation, the elastic‐plastic deformation of epoxy and the indentation force increased with rising R and h c , due to the enhanced interfacial interactions between epoxy and quartz. (2) A negative indentation force was observed during the unloading stage, attributed to adhesion effects. (3) In MD nanoscratching, the forces in the y ‐ and z ‐directions increased with rising R and h c , which was due to a greater contact zone and elastic–plastic deformation. (4) The friction coefficient could increase with rising indentation depth, exceeding 1.0 at h c / R > 0.75. (5) The classic Coulomb's law of friction was not applicable at the microscale or nanoscale. These results provide a foundation for developing interfacial models at the macroscopic scale for engineering applications.

Influence of Patch Sizes and Graphene Nanoparticles on the Flexural Behavior of Repaired <scp>GFRP</scp> Composites

2025-06-14

Binod Kumar Sahu , Chinmaya Kumar Sahoo , Ramadas Chennamsetti +1 more | Polymer Composites

ABSTRACT Composite materials are prone to damage during their operational life under static and fatigue loading. Repairing damaged components with bonded external patches offers a sustainable alternative to disposal. This … ABSTRACT Composite materials are prone to damage during their operational life under static and fatigue loading. Repairing damaged components with bonded external patches offers a sustainable alternative to disposal. This study investigates the influence of patch size and graphene nanoparticle addition at the patch‐parent interface under flexural loading. Four patch configurations were tested: 8‐layer 15 mm square, 8‐layer 15 30 mm, 16‐layer 15 mm square, and 16‐layer 15 30 mm. Static flexural tests on pristine, drilled, and patched specimens showed improvement in strength due to patch addition. These results were validated using Abaqus simulations with 2D Hashin damage criteria. For GNP reinforcement, the 8‐layer 15 mm square patch was modified with 0.3, 0.5, 0.7, and 0.9 wt% GNP at the interface. GNP addition–enhanced static strength, with a 67% maximum improvement at 0.3 wt%. Fatigue tests (75% of drilled static load) revealed a significant life reduction in drilled specimens (958 cycles) compared with pristine (62,103 cycles). Patch repair improved fatigue life, with 8‐layer and 16‐layer 15 30 mm patches surviving beyond 100,000 cycles. The 16‐layer 15 mm square patch failed between 79,000 and 97,000 cycles, and the 8‐layer 15 mm square patch between 16,000 and 21,000 cycles. Incorporating 0.3, 0.5, 0.7, and 0.9 wt% GNP in the 8‐layer 15 mm square patch improved fatigue life by 362%, 303%, 205%, and 43%, respectively, with 0.3 wt% showing the highest enhancement. Higher GNP content led to decreased fatigue performance. Displacement contours from DIC aided in analyzing the effects of patch dimensions and GNP content.

A Strong and Tough Thermosetting Epoxy Resin for Recyclable High‐Performance Composites

2025-06-14

Dongxu Pei , Peisen Wang , Jie Hao +5 more | Angewandte Chemie International Edition

Epoxy‐based carbon fiber‐reinforced composites (EP‐CFRCs) are appealing for engineering applications due to their exceptional specific strength and modulus. Nevertheless, the intrinsic brittleness and limited recyclability of highly cross‐linked epoxy matrices … Epoxy‐based carbon fiber‐reinforced composites (EP‐CFRCs) are appealing for engineering applications due to their exceptional specific strength and modulus. Nevertheless, the intrinsic brittleness and limited recyclability of highly cross‐linked epoxy matrices pose significant challenges to their sustainable development. Herein, we present an approach combining dynamic ester bonds with semi‐interpenetrating polymer networks (SIPNs) to overcome these challenges. This strategy leverages the crosslinked epoxy network to resist deformation, while hydrogen bonds and entangled SIPNs to facilitate energy dissipation, enhancing both strength and toughness. The resultant epoxy matrix exhibits superior tensile strength of 123 MPa and record‐breaking impact strength of 52.3 kJ m‐2, effectively overcoming the long‐standing trade‐off between strength and toughness in thermosets. This balanced performance renders it a promising matrix for high‐performance EP‐CFRCs, which display a tensile strength of 718 MPa and a bending deflection of 0.59 mm. Moreover, the embedded tertiary amines accelerate transesterification reactions, enabling closed‐loop recycling of EP‐CFRCs in water. The recycled carbon fibers and the degraded matrix can be reused in new composites and adhesives. This work presents a simple yet effective strategy for designing epoxy resin‐based composites that overcome the limitations of traditional matrices and support the development of recyclable advanced materials for diverse industrial applications.

Study of graphitic crystalline structure in highly porous activated carbons derived from rice husk biomass

2025-06-14

Brahamdeo Kumar Yadav , Amit Kumar | Chemical Papers

The Fracture Behavior of Carbon Fibers and Their Effects on Mechanical, Conductive, and Thermal Performance of Carbon Fibers Reinforced <scp>PPS</scp>/<scp>SEBS</scp> Blends

2025-06-14

Li Guo , Chenghong Yi , Yu Wang +3 more | Polymer Composites

ABSTRACT In this work, the fracture behavior of carbon fibers (CFs) with 2 and 10‐mm original lengths in polyphenylene sulfide (PPS)/styrene–ethylene–butylene–styrene (SEBS) blends was investigated. Experimental results found that the … ABSTRACT In this work, the fracture behavior of carbon fibers (CFs) with 2 and 10‐mm original lengths in polyphenylene sulfide (PPS)/styrene–ethylene–butylene–styrene (SEBS) blends was investigated. Experimental results found that the residual length of 2 mm of CFs in PPS/SEBS/CF composites was longer at 0.14, 0.17, and 0.22 mm for 15, 20, and 25 wt% of CFs' contents, respectively, while 10 mm of CFs was shorter as 0.11, 0.12, and 0.13 mm for that. The numerical simulation results showed that straight‐rod CFs underwent a bending–folding–breaking–fracture sequential behavior during the mixing process, and the proportion of 2 mm of CFs subjected to total squeezing forces below 10 −4 N was around 65%, which was much higher than 6 and 10 mm of original CFs. By constructing CFs' bonding bonds and calculating their retention rate, it was further verified that 2 mm of original CFs was less likely to undergo further bending–folding behavior after experiencing extensive flow field in the initial stages, also making them more stable and retaining a longer residual length in composites. Furthermore, the dimple morphology around CFs and “zig‐zag” fractured surface were observed in the composites prepared by 2 mm of original CFs, also confirming that the formation of a more robust network structure consisting of longer residual CFs and deformed SEBS. This made PPS/SEBS/CF composites show an excellent overall performance with 64.4 J/m of impact strength, 126.7 MPa of tensile strength, 0.01 S/m of electrical conductivity, and 0.65 W/m·K of thermal conductivity.

A Strong and Tough Thermosetting Epoxy Resin for Recyclable High‐Performance Composites

2025-06-14

Dongxu Pei , Peisen Wang , Jie Hao +5 more | Angewandte Chemie

Coupon-Level Experimental Material Screening of Carbon Fiber-Reinforced Polymers under Thermal Runaway Conditions for eVehicle Applications

2025-06-13

Margarita Etchegaray Bello , Ovul Ozgu Ozsoy , Jan Schöberl +5 more | Materials science forum

The shift towards electric mobility needs extensive research into battery modules, particularly in relation to safety due to the high energy density of Li-ion batteries. Battery casings must be able … The shift towards electric mobility needs extensive research into battery modules, particularly in relation to safety due to the high energy density of Li-ion batteries. Battery casings must be able to protect the module from external impacts while also containing any potential danger in the event of internal failure. This study presents a comprehensive qualitative screening of thermoset and thermoplastic carbon fiber-reinforced polymers (FRP) used in automotive and aerospace applications under thermal runaway (TR) conditions, to identify suitable materials for battery enclosures. The test setup is an adaptation of the UL 2596 standard with a hexagonal array of seven 21700-format cells. The results indicate that CF-PEEK, CF-PPS, and an aerospace-grade epoxy, CF-EP str (primary structural material) effectively contain the TR with low damage using the current setup. Medium damage was observed in CF-PC, CF-bio-based phenolic, while non-structural CF-epoxy and CF-PA6 failed to contain the TR. This qualitative study serves as an initial screening process to narrow down materials for further in-depth analysis, emphasizing the need for reproducible TR events for accurate assessment.

Ageing of carbon fibre-reinforced polymers (CFRPs) under hygro-thermal-salt conditions

2025-06-13

Wanrui Zhang , M.E. Kazemi , Behrouz Arab +1 more | Journal of Composite Materials

We investigated the ageing of carbon fibre-reinforced polymers (CFRPs) subject to hygro-thermal-salt conditions. Firstly, we manufactured a series of uni-directional (UD) CFRP specimens and exposed them to various hygro-thermal-salt conditions … We investigated the ageing of carbon fibre-reinforced polymers (CFRPs) subject to hygro-thermal-salt conditions. Firstly, we manufactured a series of uni-directional (UD) CFRP specimens and exposed them to various hygro-thermal-salt conditions containing elevated temperatures and salinities in aqueous environments for a length of three and 6 months. Following this, we characterised the performance of the UD CFRP under tensile, compression and shear loadings in both longitudinal and transverse fibre directions. Additionally, we manufactured epoxy polymer samples and exposed them to the same environmental conditions as those of CFRPs to evaluate their response under tensile loading and to better understand the degradation of the polymer constituent and its role in the performance of CFRPs subject to hygro-thermal-salt ageing conditions. Following this experimental campaign, we performed MD simulations on the monolithic epoxy polymer to obtain more insights into ageing and possibly explain mechanisms of the performance degradation that are difficult to explain solely by experiments. The experimental results demonstrate that over a 6-month period, the presence and combination of water, heat and salt can reduce: the tensile strength and Young modulus of the monolithic epoxy polymer by 31% and 17%, respectively; the longitudinal tensile strength and Young modulus of CFRPs by 15% and 3%, respectively; and the transverse tensile strength and Young modulus of CFRPs by 50% and 6%, respectively. MD simulations reveal that the presence of water reduced the glass transition temperature of the epoxy polymer.

Temperature Dependent Mechanical Properties of End-of-Life Carbon Fiber Reinforced Plastics

2025-06-13

Sangjun Jeon , Jungyeom Kim , Seong Je Park +3 more | International Journal of Precision Engineering and Manufacturing-Green Technology

A New Method of Graphene Oxide and Multi‐Walled Carbon Nanotube Grafting for Improving Mechanical Properties and Thermal Stability of Carbon Fiber‐Polylactic Acid Composites

2025-06-12

Mingrui Liu , Tian Liang , Yuxin Zhao +3 more | Polymer Composites

ABSTRACT In this study, a novel method of bridging multi‐walled carbon nanotubes (MWCNTs) with graphene oxide (GO) using a silane coupling agent was proposed. The approach involved acidifying MWCNTs to … ABSTRACT In this study, a novel method of bridging multi‐walled carbon nanotubes (MWCNTs) with graphene oxide (GO) using a silane coupling agent was proposed. The approach involved acidifying MWCNTs to generate carboxyl groups. The silane was then connected to the carboxyl groups of MWCNTs at one end and dehydrated/condensed with the hydroxyl groups of GO at the other end, forming GO‐MWCNTs hybrids. Subsequently, carbon fiber fabric laminates were prepared by combining them with pure polylactic acid (PLA), GO, MWCNTs, and their mechanical mixtures (GO/MWCNTs), respectively. FTIR and XPS analysis confirmed the success of the grafting reaction, and SEM showed that the spatial structure of the GO‐MWCNTs was more stable, which effectively inhibited the stacking of GO and the agglomeration of MWCNTs. Tensile tests and thermogravimetric analysis showed that the GO‐MWCNTs composites exhibited the most excellent tensile strength and thermal stability compared with the other groups, which proved that the modification strategy could significantly enhance the comprehensive performance of PLA‐based composites. In this study, axial and 45° bias‐extension tests of CF/PLA composites reinforced with GO‐MWCNTs (concentrations ranging from 0.2 to 1.0 wt%) were conducted. The optimal mechanical properties of the CF/PLA composites were achieved at a GO‐MWCNTs concentration of 0.2 wt%. For axial tension, the fracture strength and tensile modulus increased by 129.38% and 272.4%, respectively. Similarly, in the 45° bias‐extension tests, the strength at break and tensile modulus showed significant enhancements of 172.24% and 143.08%, respectively.

Catalyst-Free Upcycling of Thermoset Polyurethane Foams into Recyclable Carbon Fiber Composites

2025-06-12

Xing‐Qun Pu , Xiaoyu Zhang , Jiada Chen +5 more | CCS Chemistry

Relation Between Injection Molding Conditions, Fiber Length, and Mechanical Properties of Highly Reinforced Long Fiber Polypropylene: Part II Long-Term Creep Performance

2025-06-12

Jon Haitz Badiola , Udane Astobitza , Maider Iturrondobeitia +3 more | Polymers

This study investigates the long-term mechanical performance of highly reinforced long glass fiber thermoplastic polypropylene composites, focusing on the effects of processing parameters, fiber length, and skin–core structures. Dynamic mechanical … This study investigates the long-term mechanical performance of highly reinforced long glass fiber thermoplastic polypropylene composites, focusing on the effects of processing parameters, fiber length, and skin–core structures. Dynamic mechanical and creep analyses were conducted to evaluate the impact of injection molding on the final microstructure and long-term mechanical properties. The findings confirm that a significant microstructural change occurs at a fiber length of 1000 µm, which strongly influences the material’s mechanical behavior. Samples with fiber lengths above this threshold reveal greater creep resistance due to the reduced flowability that leads to more entangled, three-dimensional fiber networks in the core. This structure limits chain mobility and consequently improves the resistance to long-term deformation under load. Conversely, fiber lengths below 1000 µm promote a planar arrangement of fibers, which enhances chain relaxation, fiber orientation, and creep strain. Specifically, samples with fiber lengths exceeding 1000 µm exhibited up to a 15% lower creep strain compared to shorter fiber samples. Additionally, a direct relationship is observed between the findings in the viscoelastic response and quasi-static tensile properties from previous studies. Finally, the impact of the microstructure is more pronounced at low temperatures and becomes nearly negligible at high temperatures, indicating that beyond the glass transition temperature, the microstructural effect diminishes gradually until it becomes almost non-existent.