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As is well known, Laser print paper is usually produced with high‐quality chemical wood pulp. The laser print waste paper fiber (LPWF) is a high‐quality secondary fiber, and the research and development of high‐value utilization technology for laser print waste paper has attracted much attention in the field of renewable resource recycling. In this study, LPWF was used to reinforce poly(lactic acid) (PLA) composites in the field, and the composites were modified with bioenzyme, cationic polyacrylamide (CPAM), and nano‐silicon carbide (Nano‐SiC) to enhance the interfacial compatibility of LPWF/PLA composites. The study systematically investigated the effects of various modification methods on the characteristics and degradability of composites made from laser print waste paper fiber reinforced PLA resin matrix. The results showed that the mechanical properties of the composites treated with CPAM and Nano‐SiC were significantly improved, with tensile strengths of 54.3 and 59.5 MPa, and flexural strengths of 85.1 and 91.5 MPa, respectively, and the water absorption of the composites was reduced after the modification treatment, while the thermal stability was improved. The degradation performance of the composites in various water environments indicated that the inclusion of LPWF accelerated the water degradation rate of the composites, with the maximum degradation rate of the composite reaching 1.26% in 30 days. Highlights: Laser print waste paper is an excellent quality recyclable fiber resource.Four modifiers were used to modify LPWF/PLA composites.Characteristics and degradability of the composites were investigated.Significantly improved properties of CPAM and Nano‐SiC modified composites.The degradation rate of composites is increased by the addition of LPWF. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate (PET) is a conventional packaging material. Its modification has attracted immense attention in the industry and academia. Here, office waste paper, white cardboard waste, and waste corrugated paper were first employed as raw materials for cellulose nanocrystal (CNC) extraction by acid hydrolysis. Thereafter, CNC/PET composite films with various CNC additions were prepared via a self‐assembly technique. The results revealed that the CNCs formed a self‐assembled film on the PET surface via the synergistic effect of the complex interactions among the CNCs as well as between the CNCs and PET. Moreover, the CNCs improved the barrier property of PET and decreased the oxygen and water vapor transmittances of CNC/PET by 30.7% and 21.7%, respectively. Additionally, the coating of the PET surface with 0.2 wt.% CNCs extracted from the waste paper decreased the surface wettability of PET, exhibiting application potentials in the hydrophobic modification of polymers. This study realized waste paper recycling and provided a basis for constructing self‐assembled functional films on PET surfaces. The findings and insights of this study could exhibit application potentials in the fields of waste recycling and packaging materials. Highlights: A functional cellulose nanocrystal (CNC) film is prepared from waste paper.Self‐assembled CNC is coated on a PET surface to form a CNC/PET composite film.The synergistic interactions among CNCs and between CNC and PET modified PET.The low addition of CNCs realized the efficiency modification of PET.The study achieves waste paper recycling and high‐value utilization. [ABSTRACT FROM AUTHOR]

Nanocellulose extraction from lignocellulosic materials is a highly chemical and energy‐intensive process as it requires the removal of lignin and hemicellulose. Writing paper is one of the processed materials that could be used as a raw material for the extraction of nanocellulose. In this work, cellulose nanofibers (CNFs) were synthesized from paper waste using TEMPO‐oxidation followed by high‐shear microfluidization. Scanning electron microscopy and atomic force microscopy confirmed the diameter of fibers in the nano‐range and a consistent zeta potential confirmed the stability of CNF suspension in water over a long time frame. Characterization of the CNFs using Fourier transform infrared spectroscopy indicated the presence of a carbonyl group due to the oxidation process. Thermogravimetric analysis and x‐ray diffraction revealed lower thermal stability and reduction in the crystallinity index of CNFs, as compared to pulp fibers. The obtained CNFs were used successfully as the sole binding agent in the preparation of fiberboards and also utilized as a reinforcing agent for polyvinyl acetate (PVAc) adhesive in the preparation of laminated veneer lumber (LVLs). The addition of CNFs in PVAc improved the glue shear strength indicating superior bonding characteristics and also increased the water resistance of the LVLs. Highlights: This work focused on cellulose nanofibers (CNFs) extraction from waste paperObtained CNFs form stable water suspension and have a diameter of less than 15 nmThermal stability and crystallinity index reduced after conversion to nanofibersCNFs form a complex network and act as a sole binder to make fiberboardsCNFs were utilized as a reinforcing agent for PVAc in preparation of LVLs [ABSTRACT FROM AUTHOR]

This study investigated converting abundant paper mill waste, de‐inked paper sludge (DPS), into value‐added medium‐density fiberboard (MDF) panels. The objective was to repurpose this solid waste into a valuable material that aligns with the principles of a circular economy. Previous research has examined the addition of paper sludge to wood composites, but there is limited information on the specific incorporation of DPS into MDF production. This investigation offers new insights into this application. MDF panels were manufactured using hardwood fibers, with varying levels of urea‐formaldehyde resin (10% and 12% by weight) and different loadings of DPS (ranging from 0% to 50% by weight). X‐ray diffraction analysis revealed the presence of defective DPS fiber crystals. Contact angle measurements confirmed that DPS had poor wettability, corresponding to increased water absorption. As more DPS was incorporated, the mechanical properties of the panels progressively weakened due to defective fibers and poor adhesion between the fibers and the matrix. This was evident in scanning electron microscopy micrographs, which showed an escalation in interfacial flaws. Increasing the resin dosage noticeably improved the internal bond strength and reduced moisture uptake across all levels of DPS. However, at a DPS loading of 50%, the properties of the panels deteriorated by 36%–57% compared to the control MDF. Additionally, thickness swelling and water absorption increased significantly with higher DPS content, primarily due to the hydrophilic nature of the fibers. Based on optimization, it was determined that a DPS loading of 20% with a resin content of 12% provided the best balance between performance, waste utilization, cost, and moisture resistance. The reuse of abundant paper sludge supports the goals of a circular economy. However, strategies are required to tailor the processing methods and enable higher levels of recycled material without excessively compromising the key attributes of the product. Further research should focus on enhancing the quality of DPS and its compatibility with wood fibers and resin to enhance the performance of the composite material. Highlights: DPS from recycled paper mill assessed for MDF production with wood fibers and resinIncreasing DPS loading caused reductions in strength and adhesion of panelsWater absorption and thickness swelling markedly rose with more DPS additionIt was attributed to hydrophilic fibers and disrupted fiber‐matrix bondingOptimal formulation was 20% DPS loading and 12% resin content, balancing performance, waste utilization, and cost. [ABSTRACT FROM AUTHOR]

Highlights The graphene electrothermal de‐icing system has attracted extensive attention due to its efficient anti‐icing/de‐icing ability, but the interlayer properties of the heating layer are relatively weak. Currently, there is limited research on the interlayer properties of multilayer complex structures of graphene papers (GPs)/glass fibers (GFs)/epoxy (EP) reinforced resin composites (GPs/GE). In this study, a GPs/GE sandwich structure was prepared using a vacuum bag molding, and the effects of fabric structure and core material on the interlaminar mechanical properties of the sandwich structure were studied using the T‐peel test. A multiscale morphological investigation was conducted to analyze the crack growth and failure modes in the sandwich structures. The results indicated that the fabric structure caused anisotropy in the interlaminar peel performance of the composite material. The weft fibers contributed to inhibiting crack propagation. The GPs/GE achieved the highest peel strength of 0.533 N/mm under the (0,90)s layup configuration. The peel performance of GPs/GE was only 5.5% lower than that of conventional metal sandwich composite materials. In addition, GPs demonstrated the advantage of being lighter and thinner within the composite material. Through co‐curing bonding, the T‐peel performance of the GPs/GE sandwich structure was improved by 72.2%, thereby solving the problem of weak interlayer properties of the heating layer. Damage and failure mechanisms at different GPS/GE interfaces were explained. The fabric structure resulted in anisotropy in the peel performance of GPs/GE. The area ratio and arrangement of GPs influenced the stress distribution. GPs/GE exhibited excellent interlayer properties after co‐curing bonding. [ABSTRACT FROM AUTHOR]

Highlights To tackle the ease of aggregation issue of highly hydrophilic microfibrillated cellulose (MFC) in polypropylene (PP) that thus results in an undesired reinforcing effect, this work developed an effective and industrially feasible strategy combining pre‐quaternization of pulp fibers with paper‐making process to fabricate PP/MFC composite with enhanced performance. Effects of MFC consistency, maleic anhydride grafted polypropylene (MAPP) content, and plasma treatment of chopped PP fibers on the mechanical and thermal properties of resultant composites were systematically investigated. The surface‐quaternized MFC obtained by a low‐consistency refiner (L‐MFC) exhibited a higher aspect ratio and degree of fibrillation than the corresponding surface‐quaternized MFC obtained by a high‐consistency one (H‐MFC). It was found that there existed a synergistic effect between pre‐quaternization and the paper‐making process in promoting the dispersion of MFC in PP. As compared with L‐MFC, a higher reinforcing efficiency on PP was achieved for H‐MFC, which was because the former one was more prone to form the fibril aggregates in the PP matrix. Due to both the entangled network of MFC and its nucleation effect on PP, the heat deflection temperature (HDT) of resulting composites was largely increased up to 159.9°C, an increase of 68.7°C with respect to that of PP. The H‐MFC yielded a superior reinforcement on PP than L‐MFC. The optimum mechanical properties of PP/composites were achieved at 15% MAPP. Interfacial bonding between PP and H‐MFC was enhanced by plasma treatment. An increase in Tc of the PP matrix was noted for PP/MFC. A maximum increase of 159.9°C in HDT was achieved for PP/MFC. [ABSTRACT FROM AUTHOR]

Highlights Delamination between adjacent laminas and debonding at the fiber/metal interface are common failure modes in composites and fiber‐metal laminates (FMLs). During the initial stages, these flaws are difficult to detect because of their small size and limited applicability of existing damage‐sensing techniques due to the associated heterogeneity and anisotropy with composites and FMLs. Here, we demonstrate a feasible interlaminar damage‐sensing strategy in composites and FMLs using carbon nanotube (CNT) bucky paper (BP). The microstructure dependence of BP electrical conductivity allows it to sense the damage under varying loading conditions. The accuracy of strain sensing with BP is similar to the commercial 120 Ω strain gauge. The BP sensor accurately detects the interlaminar damage in composites (glass fiber/epoxy, carbon fiber/epoxy) and glass fiber–Al (GLARE) laminates. The delamination is marked by a steep rise in the electrical resistance of BP‐modified coupons. Moreover, the sensing capability of the BP sensor is found to be independent of the electrical conductivity of the tested coupons. Thus, the present approach is applicable to sense the interlaminar damage in a much wider class of structural composites and FMLs. Timely and accurate damage detection in composites is important to ensure their structural integrity. Electrical resistance of bucky paper (BP) varies with deformation. Performance of the BP sensor is comparable to the strain gauge at small strains. BP accurately captures interlaminar damage in composites and FMLs. BP is suitable for damage sensing in a wider class of layered materials. [ABSTRACT FROM AUTHOR]

Highlights The aerospace industries demand for advanced materials necessitates stringent quality control measures, particularly for composite structures to ensure optimal curing and structural integrity. Traditional methods like differential scanning calorimetry (DSC) and dynamic mechanical analysis, while useful, are limited to laboratory settings. This study explores the use of a printed paper‐based sensor for real‐time cure monitoring of glass fiber‐reinforced phenol‐formaldehyde (PF/GF) prepregs. The sensor, composed of a cellulose paper substrate with screen‐printed electrodes, offers flexibility, ease of integration, and cost‐effectiveness compared to commercial polymer‐based dielectric sensors. Real‐time monitoring with the printed paper‐based sensor was conducted at temperatures ranging from 130 to 180°C, both with and without pressure, and validated against DSC and Fourier‐transform infrared (FTIR) spectroscopy. The results showed a strong correlation between real‐time monitoring and the DSC prediction model, as well as FTIR spectroscopy. Notably, the real‐time monitoring revealed a shorter curing cycle on the production line than the predicted cure kinetic model, which is crucial for large‐scale production, such as fabricating honeycomb panels for aircraft interiors. This research underscores the importance of innovative sensor technologies in improving quality control and manufacturing efficiency in aerospace composites. Cure Monitoring of PF‐based prepregs was carried out using paper‐based sensor. Sensor offered reproducibility and seamless integration in composites. Sensor data showed a strong correlation with DSC and FTIR spectroscopy results. Paper sensors enable online monitoring of composite in aerospace manufacturing. [ABSTRACT FROM AUTHOR]

Mineral paper, a synthetic paper‐like material primarily composed of ground calcium carbonate (CaCO3) and a small amount of high‐density polyethylene (HDPE), has emerged as an important alternative to traditional paper and board due to the increasing demand for pulp and paper and the shortage of trees and fibrous material in many regions worldwide. This study aimed to investigate the impact of accelerated weathering and aerobic biodegradation on three different types of mineral papers. The specimens underwent 1000 h of accelerated weathering using a Gardner weathering device and were also buried in soil at a depth of 5 cm for 3 months with regular watering conditions for biodegradability testing. Physico‐chemical characterizations such as optical (whiteness), surface (roughness, contact angle, and paper topography), and chemical properties of the samples were studied before and after the artificial weathering and biodegradation tests. The results revealed a visible color change (darkening) in mineral papers, with an increase in HDPE content leading to a darker color after weathering and biological degradation. However, there were no significant differences in the color change between weathering and soil‐burial tests. The biodegradability test resulted in a decrease in ash content due to the demineralization process. All samples' surface roughness was reduced after weathering and biodegradation tests. The FT‐IR and EDS analyses confirmed the presence of calcium, carbon, and oxygen elements in all three samples, indicating a large amount of calcium carbonate in the mineral papers. The scanning electron microscopy (SEM) images showed the creation of micro holes and cracks on the surface of the samples after weathering and biodegradation. Overall, the soil‐burial test showed more degradation than the weathering test. Highlights: The influence of weathering and biodegradation of mineral papers were studiedAfter soil‐burial test, the ash content decreased due to the demineralizationAfter weathering, micro cracks were created on the surface of the samplesThe degradation of the soil‐burial test was more than the weathering testMineral papers most likely contain carbonate calcium and HDPE [ABSTRACT FROM AUTHOR]

Aramid chopped fibers/polyphenylene sulfide (ACFs/PPS) composite paper exhibits great potential for application in several cutting‐edge areas because of their excellent comprehensive properties. However, the mechanism underlying thermal aging and the role it plays in the performance of ACF/PPS composite paper remain poorly characterized. Herein, we studied the change in the chemical structure of ACFs/PPS composite paper during thermal oxidative aging and investigated the correlation between the evolution of chromophore/auxochrome groups and the development of color appearance in the ACFs/PPS composite paper. Using the color space theory, we established a correlation model among the degrees of thermal aging, the evolution of color appearance, and the changes in the mechanical properties of ACFs/PPS composite paper. On the basis of this model, the degree of aging and the corresponding mechanical strength of ACFs/PPS composite paper under different conditions could be rapidly received by estimating the change in color factor only. This study sheds new light on elucidates and provides a method for the study of polymer thermal oxidative aging. [ABSTRACT FROM AUTHOR]

Paper‐based friction materials with phenolic resin as the matrix are prone to thermal damage under harsh working conditions easily leading to materials failure. To satisfy the requirements of high speed and heavy load service situations, paper‐based friction materials with different polyimide resin content were prepared by wet forming technology to reveal the effect of polyimide resin on the properties of composites. And a paper‐based composite with phenolic resin was used for comparison. Results show that compared with the phenolic composite, tensile strength, and shear strength of the polyimide composite were increased by 50.5% and 36.4%, respectively. Due to the strong hydrogen bond in the imide ring of polyimide, the temperature of the polyimide composite at 2% weight loss was 292.7°C, which was 106.3°C higher than that of the phenolic composite. Moreover, the wear rate was reduced by 30.3% because the friction transfer film was produced during friction. To sum up, polyimide resin has the potential to replace phenolic resin under the condition of high speed and heavy load. Besides, the composite with polyimide resin content of 40.0 wt% demonstrated the best wear resistance and considerable strength attributed to the best interface combination. This research lays a theoretical foundation for the application of polyimide resin to paper‐based friction materials. [ABSTRACT FROM AUTHOR]

Light‐weight, portability and miniaturization are important characteristics for the next generation of high‐performance electromagnetic interference (EMI) shielding equipment. To meet the current demand for high‐performance EMI shielding materials, this paper proposes a simple and reliable method for preparing multilayer paper‐based composites. Paper‐based composites exhibit light weight, flexibility, easy processing and high temperature resistance. A conductive metal–organic skeleton (Ni‐CAT) layer and polypyrrole (PPy) layer were deposited on a polyimide (PI) fiber surface with an in situ synthesis and gas aggregation method to prepare paper‐based electromagnetic shielding composites with good properties. The results showed that the electromagnetic shielding effect (SE) of the paper‐based composites reached 41.0 dB. After the paper‐based composites underwent multiple ultrasonic washing and bending tests, their electrical conductivity retention rate was as high as 90%. Furthermore, the introduction of PPy/Ni‐CAT enhanced the bonding strength of the PI fibers, which caused the tensile strength of the paper‐based composites to reach 22.3 MPa. Due to the good thermal stability of the composites, they can withstand an open flame and protect the equipment during a fire. Thus, these paper‐based EMI shielding composites hold great promise for flexible electromagnetic shielding materials, protection of smart wearable devices and other fields. [ABSTRACT FROM AUTHOR]

In this paper two waste fillers, namely ground tire rubber (GTR) and coffee silverskin (CSS, a waste bio‐product from the coffee‐making process), have been used to produce sustainable ethylene‐propylene‐diene monomer (EPDM) rubber compounds vulcanized on steel sheets to fabricate rubber‐to‐steel bonded systems for industrial roofing applications. The compounds have shown good mechanical performances, with elastic moduli in the range of 13–16 MPa, tensile strength of 13–20 MPa and elongation at break >400%, and strong adhesion to the metal substrate. Moreover, the rubber‐to‐steel bonded systems present good sound insulation properties (mean sound transmission loss [STL] of 39 dB and noise level reduction in simulated hailstones impact tests of 62 dB with respect to bare steel 73 dB). Accelerated UV‐ and thermal‐aging tests have shown excellent adhesion of the compounds to the metal substrate with the CSS acting as an antioxidant agent preventing excessive polymer degradation. The selected waste‐derived materials result in promising fillers for more sustainable rubber compounds. Highlights: Waste fillers were used to produce sustainable rubber compounds.Rubber‐to‐steel bonded systems for roofing applications were produced.Rubber‐to‐steel bonded systems have good sound insulation properties.Rubber‐to‐steel bonded systems have excellent adhesion.Coffee silverskin filler acts as an antioxidant agent. [ABSTRACT FROM AUTHOR]

Reducing the dielectric constant of insulating paper to improve the dielectric coordination performance of the oil‐paper systems has always been the research hotspot in the transformer insulation material industry. This paper prepares a novel poly‐p‐phenylene terephthalamide (PPTA)/cellulose composite paper with low dielectric constant and good mechanical properties. Various PPTA/cellulose mixing structures were established and the dielectric and mechanical properties were simulated via molecular dynamics simulation. Results showed that the PPTA/cellulose composite system had a lower dielectric constant than the cellulose system, for adding PPTA molecular could reduce the free volume of the system and limit the steering polarization of the dipole, as well as decrease the system polarization intensity. Constructing a three‐layer structure that contains continuous cellulose middle layer could improve the mechanical properties of the composite system greatly. Experimental results verified the simulation results. The dielectric constant of the three‐layer PPTA/cellulose composite paper decreased from 3.98 to 3.49 at 50 Hz, compared to the conventional cellulose paper. Moreover, the tensile strength of the novel three‐layer PPTA/cellulose composite paper (thickness: 130 μm) has reached 9.02 kN/m, increased by 27.6% than the directly mixed composite paper. Molecular dynamics simulation proves to be a promising method for guiding paper modification. Constructing three‐layer PPTA/cellulose structure represents an effective way to prepare a low dielectric constant composite insulating paper with good mechanical properties. [ABSTRACT FROM AUTHOR]

Sustainable, low‐cost composite materials with improved performance typically contain, in addition to plastics, mineral fillers and fibers. Similar composite materials can also be produced by replacing fillers and fibers with side streams from paper mills using paper for recycling as their raw material. These side streams can be of different qualities and thus various end uses exist. The strength and water adsorption properties of such composites provide many opportunities for their application. Further, their environmental benefits are clear, since the use of these side streams reduces the need to landfill them. The study was also supported by chemical analysis of the side streams. This approach can also bring in additional revenue from the same raw material stream, improving overall resource and economic efficiency. POLYM. COMPOS., 39:4000–4009, 2018. © 2017 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

In this work, a novel thermal conductive and electrical insulation h‐BN@AgNPs/ANFs composite paper was fabricated by vacuum‐assisted filtration approach. Specifically, hexagonal boron nitride (h‐BN) was incorporated via polydopamine pretreatment and subsequent decoration by silver nanoparticles, which served as bridges to link neighboring h‐BN sheets. The results revealed that the thermal conductivity of as‐prepared composite paper increased to 1.032 W/m K with 40 wt% filler loading, about 464% higher than the pure ANFs paper, which was attributed to the efficient thermal conductive networks within the paper and strong interfacial combination through hydrogen bonding. Besides, the as‐prepared composite paper exhibited excellent mechanical property with the maximum tensile strength over 90 MPa, and good electrical insulation performance. More importantly, this work provided a promising strategy to achieve high thermal conductivity ANFs based composite paper by constructing efficient thermal conductive networks, which had potential to be used in the field of electronic packaging. [ABSTRACT FROM AUTHOR]

To investigate the variation of dielectric properties of epoxy resin impregnated paper insulation in different stages of partial discharge (PD) development, a PD experimental platform was established and epoxy resin impregnated paper insulation samples were prepared. According to the discharge amount, the number of discharges and discharge phenomena during the PD process, the PD process is divided into an initial stage, development stage, burst stage, and near‐breakdown stage. The variations of dielectric constant and dielectric loss factor of the sample during different PD development stages were measured by frequency domain dielectric spectrum tester. Scanning electron microscopy was used to observe the microscopic morphological changes of the samples at different stages of PD development. The surface characteristic functional groups at different stages of PD development of the sample were determined by Fourier transform infrared spectroscopy. The results show that: as the PD progresses, the insulation performance deteriorates; under continuous bombardment by high‐speed electrons, the network structure of the fiber surface and the epoxy molecular chain are destroyed, causing the weakening of the binding force between the molecular chains, and the short‐chain structure formed by cracking has a stronger steering ability. Under the continuous action of PD, the inside of the long‐chain molecule breaks and oxidizes, and a large number of small molecules, such as free radicals and monoglucose, are formed. The decrease in the molecular weight of the polymer leads to the weakening of the interaction between the molecules, resulting in an increase in polarization, a large dielectric constant, and an increase in the dielectric loss factor. [ABSTRACT FROM AUTHOR]

Increasing demands and consumption of humankind make an increase in paper production, extending the accumulation of paper production wastes. Due to legislations pertaining to environmental pollution, it has become necessary to search for new areas where these wastes could be used. Some of the processes such as milling, purification, etc. of fillers in the production of building materials are expensive and their cost reduction is desirable; therefore, the objective of this research is to develop strong and multifunctional rigid polyurethane foam composites from bio‐based polyol that are filled with unpurified and high distribution in size, having paper waste sludge (PWS) particles, and to investigate the possibility to recycle them as filler in polyurethane composites. The rational amount of PWS particles is 5% by foam mass. PWS particles improve thermal conductivity, water vapor resistance, density, compressive strength, and modulus of elasticity as compared to neat polyurethane foam matrix. POLYM. COMPOS., 39:1852–1860, 2018. © 2016 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

To create a green, safe, and aldehyde‐free indoor heating environment, an eco‐friendly emulsion polymer‐isocyanate (EPI) adhesive was applied to the preparation of electrothermal plywood with built‐in carbon fiber paper. The optimized process parameters of electrothermal plywood were 0.9 MPa, 120°C, 6 min, and 200 g/m2 for hot‐pressing pressure, temperature, time, and glue spread amount, respectively. After water immersion for 24 h, the bonding strength of wet‐treated electrothermal plywood decreased to 0.89 MPa. The pull‐out cracks of the carbon fiber paper were the main fracture form of the wet‐treated electrothermal plywood, and the wood failure percentage was 0%–10% under the tensile load. Hydrolysis of the adhesive layer of the wet‐treated electrothermal plywood occurred. The relative C and N contents in the wet‐treated electrothermal plywood decreased by 6.1% and 25.3%, respectively. Moreover, the resistance of the wet‐treated electrothermal plywood increased by 273.4% because the internal conductive path was interrupted during the intrusion of the water molecules. The highest electric‐to‐radiant transfer efficiency of the electrothermal plywood was 72.4%, with a power density of 200 W/m2. In conclusion, wet treatment has a significant effect on the bonding strength and electrothermal performance of the electrothermal plywood bonded with EPI adhesive. [ABSTRACT FROM AUTHOR]

Water based polylactic acid (PLA)‐surface modified montmorillonite (MMt) nanocomposites as biobased formulations for paper coating were successfully developed using emulsification solvent evaporation method. Electrostatic and steric stabilization mechanisms have contributed to the production of stable emulsions up to 5 months at 23 ± 1°C, revealing strong repulsive forces generated between the nanoparticles as confirmed by zeta potential (ζ) and dynamic light scattering (DLS) analysis. MMt particles were fully encapsulated by PLA as demonstrated by transmission electron microscopy (TEM) micrographs. Meanwhile the film formation process highlighted the importance of emulsifier's type and solubility in the polymer matrix, as no films were obtained when sodium oleate was used alone compared with continuous, homogeneous, and free‐standing films obtained when the combination Tween 80 (80 wt%)—sodium oleate (20 wt%) was used. Scanning electron microscopy (SEM) micrographs of the cross‐section's surfaces showed homogeneous dispersion of the MMt particles with no clusters or agglomerates formed. Thermal analyses using differential scanning calorimetry and thermogravimetric analysis (DSC‐TGA) showed an overall reduction in the glass transition temperature (Tg) and the thermal stability of neat PLA, whoever this reduction was recovered when MMt was added due to the confinement effect. Thickened PLA and PLA/MMt emulsions using 1 wt% xanthan gum showed a non‐Newtonian behavior and shear thinning flow with suitable viscosity values for paper coating applications. Highlights: Development of stable PLA/organoclay nanocomposite aqueous dispersions.Steric and electrostatic mechanisms provided excellent stability.Full encapsulation of organoclay platelets in nanometric PLA particles.Formation of free‐standing films from PLA/organoclay emulsions.Thickened PLA/organoclay emulsions using Xanthan gum for paper coatings. [ABSTRACT FROM AUTHOR]

Aramid materials have been applied in many important civil and military fields. But a major drawback to aramid materials is the susceptibility to UV‐induced damage. In this work, aramid nanofibers (ANFs) and ANF/nano‐ZnO composites were used to protect aramid materials from UV‐induced damage. ANF protective layer was created on the surface of aramid fibers, and the ANF‐coated aramid fibers could be further prepared to aramid paper. Moreover, ANF/nano‐ZnO composites were synthesized and used for stronger UV‐blocking ability. ANFs provided effective protection to aramid material. The properties after UV exposure (about 9.3 years in the natural environment) were largely improved: ANFs improved the retention rate of strength by 17.96% for aramid fibers and by 16.93% for aramid paper. ANFs also showed synergistic effect with UV‐absorbing inorganic nanoparticles. After UV exposure, the tensile strength of aramid paper with ANF/nano‐ZnO composites was even higher than the initial value (121.55%), and the retention rate of strength was 2.43 times higher than the original aramid paper. [ABSTRACT FROM AUTHOR]

Multiwalled carbon nanotubes (MWCNTs) have extraordinary electrical conductivity but limited applications due to the ease of agglomeration, especially in thermoplastic composite. With the aim of achieving high electromagnetic interference shielding performance by applying MWCNTs in thermoplastic matrix, MWCNTs were made into buckypaper (BP) and then hot pressed with PP/PLA/TiO2 hybrid films, forming sandwich‐structured BP/PP‐PLA‐TiO2 hybrid composite films. BP was examined in terms of morphology, cell structure, and electrical conductivity, while BP/PP‐PLA‐TiO2 hybrid composite film was tested for electromagnetic shielding effectiveness (EMSE), thermal properties and UV‐cut efficacy. It was found that using vacuum filtration successfully produced BP with a smooth and sleek surface and an even porosity ranging between 20 and 45 nm. The electrical conductivity of BP was proportional to its thickness. About 90 μm‐thick BP had 75.62% lower surface resistivity and 36.63% higher electrical conductivity than 30 μm‐thick BP. Moreover, the EMSE of BP/PP‐PLA‐TiO2 composite film increased as a result of the higher thickness of BP. When the thickness of BPs was 90 μm, the BP/PP‐PLA‐TiO2 composite film had an average EMSE of 40 dB at 0–3 GHz and a peak of 70 dB, and 119% higher tensile strength and 11% higher elastic modulus than those of PP/PLA/TiO2 composite film. BP/PP‐PLA‐TiO2 composite film had UV‐cut efficacy that was close to 0%. The addition of BP was proven to improve the crystallization and thermal stability. POLYM. COMPOS., 40:3065–3074, 2019. © 2018 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

In this work, poly(para-phenylene terephthalamide) (PPTA) paper sheets composed of PPTA fibers and PPTA fibrids filled with highly crystalline and high ratio of length to diameter potassium titanate whiskers (PTW) were investigated in view of possible employment as reinforcement and cost-reducing materials. The morphological characteristics and the role of PPTA fibrids, the influence of PTW on the mechanical properties, interfacial adhesion, and thermal stability of the PPTA paper sheets were discussed. The results showed that the ductile, flexible and rough morphological characteristics of PPTA fibrids are helpful to improve the properties of PPTA paper. PTTA fibrids strongly wrapped PTW in the PPTA paper sheet was observed, which largely enhanced the retention rate of PTW and further improved the interfacial combination. The presence of PTW improved the mechanical properties and thermal stability of PPTA paper sheets. This research demonstrated the improvement of thermal and mechanical performances of PPTA paper sheets by incorporating of PTW, suggesting a significant cost-reducing potential for the production of PPTA paper composite materials. POLYM. COMPOS., 38:1390-1395, 2017. © 2015 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Highlights To meet the urgent demands of aerospace vehicle upgrades and replacements, which require honeycomb structures with higher specific strength and environmental adaptability, the development of lightweight and high‐strength short‐cut carbon fiber reinforced polymer (S‐CFRP) honeycombs is an effective approach. First, this study designed a hot pressing process, which was utilized for the fabrication of both short‐cut CF paper and S‐CFRP honeycomb. Second, a finite element model was established to predict the mechanical performance of the S‐CFRP honeycomb. Finally, mechanical experiments were conducted on the S‐CFRP honeycomb and the failure factors were analyzed. The S‐CFRP honeycomb features cell edges as low as 2.75 mm in length, with a density reduced to 47.6 kg/m3, achieving the coexistence of small cell edge length and low density in the honeycomb structure. Compared with the aramid honeycomb of 48.06 kg/m3 from Hexcel Corporation, the compressive strength of the S‐CFRP honeycomb was increased by 21%, and the shear strengths in the L and W directions were improved by 42% and 59%, respectively. This study provides a fabrication method and simulation model for low‐cost, lightweight, high‐strength S‐CFRP honeycombs, which has significant engineering value for enhancing the weight reduction efficiency and the mechanical performance of aircraft structures. A low‐cost, high‐strength short‐cut CF paper has been prepared. An S‐CFRP honeycomb, lightweight and with small cells, has been made. The strength of S‐CFRP honeycombs exceeds that of aramid ones. The failure factors of the S‐CFRP honeycomb were analyzed. Performed accurate mechanical simulation analysis on S‐CFRP honeycomb. [ABSTRACT FROM AUTHOR]

Highlights With the growing environmental concerns and strict regulations, the shift from traditional brake pad materials such as copper, asbestos to eco‐friendly materials has become necessary. This review paper presents an in‐depth analysis of natural fibers (fibers obtained from plants) brake pads, an emerging sustainable alternative in automotive technology. Natural fibers such as jute, kenaf, flax etc. offers a good solution due to their renewable nature, low cost and reduced environmental impact. This paper explores the properties of natural fibers that make them suitable for use in brake pads including their thermal stability, wear resistance and ability to withstand high‐friction environments. It highlights the advantages and challenges of natural fiber composites particularly in terms of performance, durability, and noise reduction. The environmental benefits including biodegradability and reduced carbon footprint are discussed underscoring the role of natural fiber brake pads in promoting sustainable automotive practices. This paper aims to provide a comprehensive overview of the current and future potential of natural fiber brake pads offering valuable insights for researchers and industries in the field of sustainable automotive engineering. Shift to natural fibers from asbestos and copper for eco‐friendly alternatives. Natural fibers offer biodegradability, low cost, and good mechanical properties. Fiber variability and moisture absorption pose challenges, needing treatments. Natural fibers reduce environmental impact, supporting sustainable practices. More research is needed on fiber treatment and standardized testing protocols. [ABSTRACT FROM AUTHOR]

Process modeling is an indispensable tool for establishing a foundation for process optimization and enhancing the quality of products. Analyzing the thermoforming process of polymer matrix composites presupposes the acquisition of accurate thermal histories. This paper introduces a numerical solution based on the finite difference (FD) model to predict the temperature field of angle‐ply composite structures during automated fiber placement (AFP) process along the machining trajectory. The proposed method incorporates three‐dimensional hybrid boundary conditions and considers temperature‐dependent material properties, significantly improving efficiency compared to the finite element (FE) model and overcoming challenges related to complex boundary conditions and anisotropic heat transfer in analytical solutions. Real‐time temperature measurement experiments were conducted to validate predictions, and further a specific temperature control strategy that meets process requirements was explored. In summary, the paper introduces a novel approach to address the temperature field in complex composite structure manufacturing processes. Highlights: A novel 3D finite difference model predicts the temperature field in automated fiber placement.Improved prediction accuracy by managing complex boundary conditions.Effectively handled anisotropic heat transfer in complex composite structures.Superior efficiency over existing numerical methods.Developed a model‐based strategy for optimal temperature control within ±5°C. [ABSTRACT FROM AUTHOR]

Highlights Thermoplastic polyacrylate resin, which can be polymerized in situ, has a broad application prospect. Addressing the issue of poor toughness of polyacrylate resin, a toughening method involving in situ polymerization of polyacrylate resin for liquid composite molding was presented in this paper. KH570‐modified silica nanoparticles were used as reinforcement. The study focused on the surface modification's impact on the dispersion stability of the nanoparticle suspension, the effect of nanoparticles on the reaction, and the mechanical properties of the resin. The results showed that the contact angle between modified‐silica and acrylate resin decreased from 79.3° to 9.96°, and the stability of the suspension was increased by 34.8%. With the increase of silica nanoparticles, the reaction speed of the resin initially decreased and then increased. This was due to the influence of KH570 on the surface of the nanoparticles and the changes in resin viscosity caused by the nanoparticles. The mechanical properties of polymerization products first increased and then decreased. When nanoparticles mass ratio of nanoparticle to resin was 5:100, the elongation at break was increased by 94.9%, the impact strength was increased by 287%. This paper provided some ideas for high‐performance industrial application of high‐performance in situ polymerization of polyacrylate resin. The thermoplastic polyacrylate resin that can be formed by liquid composite molding. A method for improving the toughness of resin used in liquid composite molding. Nanosilica modified with KH570 interferes with the reaction of acrylate resin. The nanosilica changes the crack propagation path. [ABSTRACT FROM AUTHOR]

Reversible cross‐linked structures are widely used to turn thermoset plastics into recyclable and self‐healing vitrimer materials, but seldom applied in traditional flexible rubber/ceramic composites. In this paper, dioxaborolanes based flexible poly (isoprene (IP)‐co‐acrylonitrile (AN)) vitrimer is synthesized as the rubber matrix by copolymerizing with functional monomers at 5°C for 7 h, and mixed with 5 wt% modified barium titanates (BT) to prepare flexible high dielectric vitrimer composite. The materials are characterized by FTIR, TGA, SEM, DMA, etc. The results indicate that reversible crosslinking can occur above 76.4°C, and copolymerizing with the dioxaborolanes based monomers can turn poly (IP‐co‐AN) into the flexible vitrimer. The poly (IP‐co‐AN)/BT vitrimer composite not only shows a good thermal stability below 145.6°C, but also exhibits an excellent particle dispersivity and a certain self‐healing function at 80°C. The poly (IP‐co‐AN)/BT vitrimer composite has a storage modulus E' about 3.18 MPa at 25°C and Tg about −5.4°C, and shows a higher relative permittivity about 7.5 and lower dielectric loss about 0.156 at 1 k Hz. The results indicate that this paper provides a new method to achieve multifunction and high dielectricity for composites. Highlight: Reversible cross‐linked structures are applied in rubber / ceramic compositesCross‐linked flexible composites are reprocessable and self‐healingReversible bonds between particles and matrix improve compatibilitySynergism of BaTiO3 and cross‐linked structure enhances dielectric properties [ABSTRACT FROM AUTHOR]

This review paper delves into the manufacturing methods, material properties, and applications of polymer‐based composites in the field of advanced manufacturing, offering a detailed explanation of their production through various additive manufacturing (AM) techniques and their diverse applications across multiple industries. Polymer‐based composite materials have emerged as crucial elements in AM due to their enhanced properties and design versatility, enabling the creation of components with unprecedented performance characteristics. The paper comprehensively covers the major AM methods employed for composite materials, including fused filament fabrication, Digital Light Processing/Stereolithography, Direct Ink Writing, and Selective Laser Sintering. Each of these methods is explored in terms of its mechanism, suitability for different composite materials, and the resulting material properties. The review also provides an insightful analysis of how these AM techniques are revolutionizing industries such as soft robotics, mechanical, electrical, and biomedical fields. The paper concludes by discussing the current challenges in this domain and projecting future trends in the development and application of composite materials in advanced manufacturing. This review aims to offer a comprehensive resource for researchers and practitioners in the field, highlighting the transformative impact of polymer‐based composites in AM and their growing significance across various sectors. Highlights: Comprehensive review and classification of novelties in printing method for polymer based composite material manufacturing.Introduces innovative techniques to create and enhance material properties of composites.Explores interdisciplinary applications in biomedical, electronics, and sensors, demonstrating material versatility.Provides a systematic correlation between manufacturing method, material properties, and applications of novel polymer‐based composites. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive study on anisotropic heat transmission behaviors in quartz fiber fabrics. Considering the random distribution characteristic of fibers within the yarn, an innovative two‐scale finite element method (tFEM) is introduced, incorporating multiple micro‐scale fiber models (MMFM) based on scanning electron microscope (SEM) observations. MMFM are divided into 8 distinct models to capture intricate fiber arrangements. The macro‐scale fabric model is constructed based on the geometric structure analysis by Micro‐CT technology. Both micro‐ and macro‐scale models are assembled with the air matrix to form the two‐phase composite model. The Hot‐Disk thermal analysis instrument is applied to measure the anisotropic thermal conductivity (ATC). Numerical results from MMFM shows more excellent agreements with the experimental ones at 3D orthogonal directions of fabrics, i.e., the error rates of the thermal conductivity in the warp, weft and thickness directions between numerical and experimental methods are all less than 3%, which indicates the tFEM including MMFM in this paper is more accurate than the tFEM including OSMFM. In addition, the temperature distribution and heat transmission differences due to fiber arrangements are simulated and illustrated through the MMFM. Afterwards, temperature drop and isothermal characteristics are demonstrated in this study. Highlights: Effects of fiber arrangements on steady heat transfer behaviors at micro‐scale are illustrated.Isothermal and temperature‐drop characteristics at micro‐ and macro‐scale are simulated and studied.The transverse isotropy of thermal conductivity at micro‐scale and the anisotropy of that at macro‐scale are revealed. [ABSTRACT FROM AUTHOR]

Highlights Carbon fiber reinforced polymers (CFRPs) have received widespread attention due to their excellent mechanical properties. However, the poor interfacial properties between CF and resin matrix urgently need feasible and efficient surface modification strategies of CF to regulate the interface. Due to its unique layered structure and abundant surface groups, MXene has been increasingly used in the field of CFRP interfacial modification in recent years. It possesses the advantages of good stability, large specific surface area, abundant adsorption sites and rich functional groups, which could effectively improve surface polarity, roughness and wettability of carbon fibers, thus enhancing effective interfacial bonding and enabling hierarchical regulation of interface in CFRPs. This paper reviews feasible strategies for constructing CF‐MXene multilevel structures, including electrophoretic deposition, chemical grafting, electrostatic self‐assembly, and sizing coating. Then, the strengthening mechanism involving surface morphology, mechanical properties, and interfacial strength of CFRPs are systematically evaluated centered on interfacial activity, interfacial adhesion, surface roughness and surface energy. Meanwhile, the problems in introducing MXene to CF surfaces and future research directions are systematically prospected. This paper could provide valuable guidance to construct CF‐MXene multilevel structures to reinforce interfacial properties of CFRPs composites, thus realizing hierarchical modulation of CFRPs interfaces. A feasible strategy for constructing CF‐MXene multilevel structures is built. The main methods for constructing CF‐MXene multilevel structures are provided. Treatment processes and reinforcing mechanisms of CFRPs are evaluated. [ABSTRACT FROM AUTHOR]

Highlights Carbon fiber reinforced polymer (CFRP) is a high‐performance composite material composed of carbon fibers embedded in a polymer matrix. CFRP is extensively used in various sectors such as aerospace, automotive, sports equipment, and construction due to its advantageous properties. Laser processing offers numerous advantages when working with carbon fiber‐reinforced composites, including its non‐contact nature, precision, efficiency, and controllability. However, disparities between carbon fibers and the polymer matrix can lead to challenges during laser processing, such as delamination, heat‐affected zones, and fiber pullout. Consequently, there is a substantial body of literature focusing on improving the quality and efficiency of laser processing for CFRP materials. This paper provides a comprehensive review of various studies investigating the impact of laser parameters (laser mode, pulse frequency, pulse width, and laser wavelength) on carbon fiber‐reinforced plastics. It discusses how different laser parameters affect the processing quality and performance of these materials. Additionally, drawing from recent research findings, the paper explores potential future trends in laser processing for carbon fiber‐reinforced plastics. The application of laser technology in CFRP, including laser cutting, drilling, welding, and surface treatment, has been extensively researched. A detailed discussion is held regarding the impact of laser mode, wavelength, frequency, and pulse width on the quality of machining. More auxiliary processing has evolved in CFRP manufacturing due to the ongoing advancements in laser technology. The goals of laser processing CFRP technology are increasingly focused on reducing carbon emissions, enhancing energy efficiency, and minimizing waste. [ABSTRACT FROM AUTHOR]

Highlights The performance of carbon fiber‐reinforced thermoplastic composites (CFRTP) has been restricted by the performance of the interface. In general, the interfacial properties of CFRTP are determined by both the surface properties of the carbon fiber (CF) reinforcement and the infiltration properties of the thermoplastic matrices, which possess high melt viscosity and seem difficult to sufficiently infiltrate the fiber reinforcement. As a result, the melt flow characteristics of different matrices significantly influence the interfacial melt penetration and mechanical properties of CFRTP. In this paper, in order to explore the influence of melt flow characteristics of various thermoplastic resins toward CFRTP interfacial behaviors, high‐polarity polyamide (PA) and low‐polarity polypropylene (PP) resins are selected as representative resin matrices among commonly used resin systems. Specifically, the polarity differences and interface‐forming mechanisms of CFRTP are first established. Following a systematical discourse on the latest research progress of interfacial modifications in PP/PA‐based CFRTP are described, centering on the effects of various modification methods on improving the interlaminar/interfacial strength, toughness, impact strength, and bending strength of the composites. In addition, this paper also classifies the interfacial mechanisms of CFRTP in terms of interface bonding, interface strengthening, and interface failure. Finally, the shortcomings and future research directions are pointed out to achieve effective interfacial construction and innovative modification of CFRTP. An introduction of resin polarity differences of CFRTP is established. An introduction of interface‐forming mechanisms of CFRTP is established. State‐of‐art characterization techniques of CFRPs interface are provided. Effect of melt flow property on the interfacial behavior of CFRTP was explored. The interfacial mechanisms are systematically analyzed. [ABSTRACT FROM AUTHOR]

Highlights In this paper, the mechanical properties and vibration characteristics of Carbon‐Glass Hybrid Fiber Composites (CGHFC) are experimentally investigated with varying axial directions and blending ratios. The experimental results demonstrate a significant increase in the tensile strength of the CGHFC with an increasing content of carbon fibers. The biaxially CGHFC exhibits a maximum static tensile strength of 413.27 MPa in the 0° direction and 466.33 MPa in the 90° direction, surpassing both the quadratic and uniaxial directions. Notably, compared to biaxially oriented glass fiber material, the tensile strength of CGHFC is enhanced by 44.36%, thereby significantly improving its overall performance, making them particularly suitable for blade structures subjected to simultaneous tensile and vibratory loads. By optimizing the fiber orientation and blend ratio, the CGHFC provides good vibration control and fatigue resistance while ensuring high strength, thus maximizing the overall performance and service life of the blades. The results of this paper provide important data and theoretical support for the selection and design of wind turbine blade materials and help to promote the development of composite materials in wind turbine blade structure and design. CGHFCs show enhanced tensile strength with more carbon fibers. Biaxial CGHFCs have max tensile strength at 0° and 90° directions. CGHFCs' strength improves by 44.36% over glass fiber materials. Optimized CGHFCs offer superior vibration control and fatigue resistance. Research supports wind turbine blade material innovation. [ABSTRACT FROM AUTHOR]

Textile composites are advanced materials composed of preforms combined with matrix materials. The fiber structure in the preform has a significant impact on the mechanical properties of the composite. Precise control over preform dimensions and internal fiber structural uniformity, termed 'accurate shape control', is essential to ensure reliable and stable composite component mechanical properties. This paper reviews current research progress on fabric deformation mechanisms, focusing on experimental characterization and numerical simulation. Experimental methods for fabric deformation include tensile, compression, bending, and shear deformation, whereas numerical methods encompass macroscopic continuum, discrete, and semi‐discrete models. The insights offered in this paper will aid a greater understanding of fabric deformation mechanisms, enabling an accurate prediction of complex shape molding and effective process parameter design, ultimately facilitating the structural design and engineering applications of textile composites. Highlights: Recent trends and challenges in the study of fabric deformation mechanisms are presented.The experimental methods for fabric deformation were summarized and evaluated.Representative numerical modeling techniques and simulation methods are discussed.Some recommendations on potential future research directions are detailed. [ABSTRACT FROM AUTHOR]

At present, it exists the problems of poor computational accuracy of the micromechanical model and insufficient adaptive matching of the RVE unit cell model boundary conditions, being caused by the random distribution of particle size and quantity in particle composite materials. As for the above problems, the paper proposes a micromechanical model that uses a random sequence adsorption algorithm to deeply match and enhance the random distribution of particles, and a subroutine joint simulation method to generate boundary conditions quickly and automatically. The RVE unit cell model of particulate composites are numerically simulated at the micromechanical level. It was found that the enhancement of the mechanical properties of the base material by enhancing particles is highly consistent with the actual improvement value. The simulation values and actual values of particle composite materials with different volume contents are also accurately consistent. In addition, with the increase of particle volume content, its reinforcement effect on the base material first increases and then decreases, and there exists an optimal mixing ratio and a minimum mixing ratio. The optimal mixing ratio for short cut fiber reinforced particles is 50%, with a minimum mixing ratio of 10%. The optimal mixing ratio for silicon carbide reinforced particles is 40%, with a minimum mixing ratio of 8%. Through experimental results, it has been verified that the micromechanical model can quickly and accurately predict the elastic constants and Poisson's ratio of composite materials under periodic displacement boundary conditions, with a prediction accuracy of within 10%. Highlights: Effectively solve the problems such as the random distribution of the size and quantity of reinforced particles in the particle composite material and the difficulty in adding the boundary conditions of the micro‐RVE unit cell model in the macro composite material.A random sequence adsorption algorithm is proposed to generate the RVE cell model with reinforced particles, and the periodic displacement boundary conditions are added to the RVE cell model through Python and Abaqus joint simulation.The simulation results show that the stress of chopped fiber reinforced particles is about 1.96 times that of the matrix material, and the stress of SiC reinforced particles is about 2.1 times that of the matrix material, and the optimal mixing ratio of chopped fiber reinforced particles is 50% and that of silicon carbide reinforced particles is 40%.The proposed micromechanical model can accurately predict the elastic constants of composites under periodic boundary conditions, and its prediction accuracy can be controlled within 10%.In this paper, a more reasonable meso‐stress‐strain field of single cell element is given, which can provide reference for studying the meso‐failure mechanism and nonlinear mechanical behavior of particle composites. [ABSTRACT FROM AUTHOR]

The classification of ablation images holds significant practical value in thermal protection structures, as it enables the assessment of heat and corrosion resistance of composites. This paper proposes an image‐based deep learning framework to identify the surface texture of carbon/phenolic composites ablative images. First, ablation experiments and collection of surface texture images of carbon/phenolic composites under different thermal environments were conducted in an electric arc wind tunnel. Then, a deep learning model based on a convolutional neural network (CNN) is developed for ablative image classification. The pre‐trained network is ultimately employed as the input for transfer learning. The network's feature extraction layer is trained using the ImageNet dataset, while the global average pooling addresses specific classification tasks. The test results demonstrate that the proposed method effectively classifies the relatively small surface texture dataset, enhances the classification performance of ablative surface texture with an accuracy of up to 97.6%, and exhibits robustness and generalization capabilities. Highlights: The paper proposes a new deep learning classification method for ablative images.A model highly sensitive to small and weak features is built.Transfer learning and data enhancement techniques are introduced into classification. [ABSTRACT FROM AUTHOR]

Highlights Carbon fiber reinforced polyetherketoneketone (CF/PEKK) possess excellent mechanical properties and also meet low‐carbon environmental standards, leading to their increasingly widespread application in recent years. To ensure the strength of mechanical connections, it is crucial to minimize drilling damage. This paper utilizes Ultrasonic Vibration‐Assisted Drilling (UVAD) to enhance hole‐making quality, comparing multiple drilling performance indicators with Conventional Drilling (CD), including thrust force, drilling temperature, delamination factor, and burr factor. The results demonstrate that UVAD significantly reduces thrust force and drilling temperature, decreases delamination and burring damage, and effectively improves hole quality. To further optimize processing parameters, the Non‐dominated Sorting Genetic Algorithm II (NSGA‐II) was used, targeting thrust force, Material removal rate (MRR), and delamination factor as optimization goals. The reliability of the model was verified through experimentations. This paper provides an effective technical approach for high‐quality drilling in CF/PEKK materials, offering significant practical application value for material processing in aerospace and other fields. The quality of CF/PEKK processed by CD and UVAD was compared. UVAD can effectively improve the quality of drilling. The drilling parameters were optimized by NSGA‐II. The reliability of the prediction model was verified by experiments. [ABSTRACT FROM AUTHOR]

Highlights Functionalized thin films with excellent flexibility and conductivity can meet the current requirements for electromagnetic(EM) shielding materials. In this paper, 2D transitions metal carbide and nitride nanomaterials Ti3C2Tx MXene were prepared by chemical exfoliation, and PVDF/MWCNTs/3 wt%/RGO@Fe3O4@ AgNWs‐10 based on PVDF/MWCNTs‐3 wt%/RGO@Fe3O4@AgNWs‐10, The samples were prepared through a simple solution mixing process followed by vacuum‐assisted filtration (VAF), and PVDF/MWCNTs/MXene/RGO@Fe3O4@AgNWs three‐layer PVDF‐based composite films, which were analyzed for electrical conductivity and EM shielding properties, which increased and then decreased with the rise in the Ti3C2Tx MXene content, in which the highest electrical conductivity of the three‐layer composite films of M3/MX‐10/R@F@Ag was obtained when the Ti3C2Tx MXene addition amount reached 10 mL as 3.9 × 103 S/m, the EMI SET is 54.9 dB, the EMI SEA is 44.8 dB, the absorption loss is 81.6%, and the SSEt of the M3/MX‐10/R@F@Ag three‐layer composite film is the highest 1672.5 dB/(cm−2·g). And the SEA/SER ratios of the M3/MX‐X/R@F@Ag three‐layer composite films are all greater than 1. The result shows that the EM attenuation mechanism of the M3/MX‐X/R@F@Ag three‐layer composite films is primarily driven by absorption loss and that the incorporation of Ti3C2Tx Mxene improves the EM shielding performance of the composite films. The relatively novel exploration of the performance study and structural design of the M3/MX‐X/R@F@Ag three‐layer EM shielding composite film provides structural design and research ideas for the application of the new MXenes material in EM shielding composites. The addition of Ti3C2Tx MXene will generate more conductive network nodules A complete 3D conductive network is constructed in the membrane This paper discusses the influence of Ti3C2Tx MXene on EM shielding Multiple internal reflections of EMW between Ti3C2Tx MXene 2D nanosheets The EM shielding mechanism of the film is discussed from the angle of 3D [ABSTRACT FROM AUTHOR]

Highlights Considering the types of carbon fiber reinforced polymer (CFRP) waste and the length of recycled carbon fiber (rCF), it is still a challenge to obtain high‐performance rCF and realize its high‐value reuse. In this paper, rCF was obtained by the thermal activated oxide semiconductor, and the effects of temperature and time on the resin decomposition rate of CFRP with different resin systems were analyzed. Three remanufacturing processes, namely wet fiber alignment (WFA), direct ink writing (DIW) and fused deposition modeling (FDM), were used to remanufacture rCF in millimeter and micron scale into recycled carbon fiber reinforced polymer (rCFRP) and the effects of rCF content on the mechanical properties of rCFRP were studied. The results showed that the optimal recycling parameter for EP‐EDA is 520°C, 45 min, and for EP‐MeTHPA and phenolic resin, the optimal recycling parameter is 520°C, 35 min. With the increase of rCF content, the tensile strength and modulus of WFA, DIW and FDM samples all increased to varying degrees. When the rCF content is 15 wt%, the tensile strength of WFA, DIW and FDM samples is increased by 355.6%, 68.4%, and 34.5%, respectively, compared with the corresponding pure resin samples. The mechanical properties of WFA, DIW and FDM samples are greatly different due to the rCF content, rCF length, interface bonding and alignment of rCF. This paper emphasizes the important effects of remanufacturing process, material composition and rCF content on the properties of rCFRP, and provides multiple ways for high‐value reuse of rCF. rCF obtained by thermal activated oxide semiconductor. Resin decomposition rate of CFRP waste with different resin systems. Multiple remanufacturing processes for rCF. Effects of rCF content and material composition on the properties of rCFRP. [ABSTRACT FROM AUTHOR]

This article studies the potential of deinking paper sludge (DPS) and recycled high density polyethylene (RHDPE) for biocomposites (DPS/RHDPE). Different DPS loadings (0 to 20 wt%) and compatibilizer content (0 to 4 wt%) were used in (DPS/RHDPE) formulations. A commercial paper wet‐strength agent polyamideamine‐epichlorohydrin resin (PAE) was used as DPS binder. The effects of DPS composition and PAE content on RHDPE/DPS biocomposites performance were studied. First, the chemical composition, morphology and thermal behavior of DPS were characterized using X‐ray diffraction, scanning electron microscopy, fiber quality analyser, and thermogravimetric analyses. The effect of the chemical treatment was evaluated using infrared spectroscopy (FTIR). Finally, crystallization behavior and tensile properties of DPS based biocomposites were discussed. Results revealed that DPS have a nucleating effect thanks to the presence of minerals such as calcium carbonate and talc. DPS increased the stiffness and the tensile strength of RHDPE. PAE could also serve as a compatibilizer between fibers and RHDPE. POLYM. COMPOS., 39:616–623, 2018. © 2016 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Recently, chitosan is discovered as a most abundant natural polymer, which is not only a lightweight, low‐cost, sustainable resource with potentials in energy transformation, but also biocompatibility and biodegradability. In this article, they investigated a highly biocompatible chitosan‐based electro‐active polymer (C‐Polymer) actuator composed of multiwall carbon nanotube, ionic liquid, and polymer‐supported chitosan. As a result, after the changed MCNTs rate (20%, 40%, 60%, and 80%) in the electrode membrane, actuation properties of C‐polymer actuator behaved a great enhancement. With the increase of the ratio of MCNTs, the specific capacitance and the electrode resistance were obviously improved, which were 2.02 F/g and 1.32 Ω under rate of 80%, and the maximum displacement and the response speed behaved a peak value of 7 mm (80%) and 0.032 mm/s (80%). Interestingly, it also showed an increasing for the maximum blocking force and response speed under the ratio of 80%, which presented the maximum value of 6.80 mN and 0.11 mN/s. In order to analyze causes for this enhancement, a valid generated strain values were calculated to evaluate the strain on the electrode layer. However, it is exhibited that the generated strain was very small, which almost kept in the value of 0.5%, and it was unrelated to Young's modulus. Moreover, they also found that the resistance and the specific capacitance could strongly affect the electromechanical properties of C‐polymer actuator with different rate of MCNTs, and revealed a vital potential Ramsay rule between the electrochemical properties and electromechanical properties of C‐polymer actuator. POLYM. COMPOS., 39:E228–E235, 2018. © 2016 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

In this paper, the reasons for the improved wear resistance of irradiation‐modified Polytetrafluoroethylene (RM‐PTFE) and its composites above the melting point were investigated from the microcrystalline point of view by using methods such as crystallization kinetics, and it was found that the linear wear rate of RM‐PTFE was only 0.3 um/km, with a 1000 times increase in wear resistance, which was due to the transformation of its crystals from flake crystals that were easily dislodged to spherical crystals that were more resistant to abrasion. It was also found that the linear wear rate of Polytetrafluoroethylene (PTFE) with coke and graphite was 0.2 and 0.1 μm/km, respectively, and the abrasion resistance was further improved, which was attributed to the lowering of spherical crystal grain size by coke and graphite, which had better mechanical properties. These studies lay the foundation for future research on the frictional wear mechanism of RM‐PTFE above the melting point. Highlights: Irradiation‐modified PTFE above the melting pointWear resistance of PTFE increases 1000 timesChanges in crystal morphology dramatically increase wear resistanceUse of crystallization kinetics to study the crystalline form of PTFESmall grain size improves wear resistance [ABSTRACT FROM AUTHOR]

Glass fiber reinforced plastics (GFRPs) is a key material for the outer protecting layer of ships as well as for energy storage tanks. Its ballistic and blast resistance is closely related to the inclusion structure of its glass fiber and polyester matrix, however, the related detailed studies have not been reported. In this paper, ballistic shooting tests and finite element simulations are both employed to investigate the ballistic limit velocities (V50) of GFRPs and reveal the effects of glass fiber layers and the polyester matrix thickness on the V50. The results show that the V50 of GFRPs is essentially linearly related to the thickness of the target plate for a given number of glass fiber layers. An increase in the number of glass fiber layers enhances the overall V50 value of GFRPs, but the linear relationship with the thickness remains unchanged. The target plate with more layers of glass fiber interacts with the projectile for a longer time, resulting in the debonding of the fiber and the resin matrix. The resin around the crater loses its support and then produces irregular cracks. Based on energy conservation, a theoretical model for predicting the V50 of GFRPs with considering the effects of glass fiber and polyester matrix is proposed. After comparing the results of theoretical calculations with experimental and simulation data, the relationship equations between the key parameters (ballistic strength) in the model and the number of fiber layers and target plate thickness are finally given. These findings can provide support for the design of ballistic GFRPs. Highlights: Ballistic velocity limit (V50) of glass fiber reinforced plastics (GFRPs) obtained by experiment and finite element simulationTuning the V50 of GFRPs by designing the number of glass fiber and polyester thickness.Proposed a theoretical model for predicting the V50 of GFRPs. [ABSTRACT FROM AUTHOR]

This paper reports on preparing two types of graphene oxide‐zinc oxide (GO‐ZnO) nano‐hybrids and their effect on the performance of polybutylene succinate (PBS) matrix. This view synthesized GO, ZnO, and GO‐ZnO nano‐hybrids at 1:1 and 1:2 weight ratios. Subsequently, various spectroscopy and microscopy analyses (FTIR, UV, Raman, AFM, and TEM) were employed to characterize the structure of synthesized nanomaterials. The obtained results revealed that the hybridization was successfully occurred and microstructure of two types of prepared nano‐hybrids are basically different depending on the preparation procedure. Following this, PBS nanocomposites with 0.5, 1, and 1.5 wt% of GO‐ZnO nano‐hybrids (NPs) were produced via the solvent‐blending method. The mechanical, microstructural, rheological, biodegradability and UV‐shielding properties of the fabricated films were then investigated. Mechanical properties showed that addition of 0.5 wt% ZnO‐GO nanohybrids improved elongation at break from 21.6% to 28.7% and increased tensile strength by 20%. However, rheological assessments showed a one‐order‐of‐magnitude decrease in viscosity with the addition of only 0.5 wt%. In degradation analysis, 100 percent of mass loss was observed during 5 weeks for PBS with 1.5 wt% of GO‐ZnO. PBS/GO‐ZnO nanocomposites indicated tailored mechanical properties, biodegradability, suggesting a promising potential in packaging applications. Highlights: GO‐ZnO nanohybrids were successfully synthesized.Incorporating GO‐ZnO into PBS improved its hydrolytic degradationThe thermal decomposition of PBS was accelerated by the addition of GO‐ZnO.Adding GO‐ZnO nanohybrids to PBS resulted in a drop in viscosity.Nanohybrids with higher ZnO content exhibited greater hydrolytic and thermal degradation. [ABSTRACT FROM AUTHOR]

To improve the subpar lubricating performance of epoxy resin, this paper presents the preparation of a novel bimetallic phyllosilicate featuring a distinctive rice‐granular morphology, which incorporates nickel and iron metal cations through a facile hydrothermal process. These phyllosilicates were then integrated into the epoxy matrix to form composites. A comprehensive analysis of the target product validates the rationality of the synthesis strategy for the as‐prepared rice‐granular bimetallic nickel/iron phyllosilicate, demonstrating a homogeneous hierarchical structure with numerous tiny nanosheets of nickel/iron phyllosilicate grown in situ on the flat surfaces of the rice‐granular metal–organic frameworks. An adequate addition of nickel/iron phyllosilicates allows for excellent dispersion within the matrix and establishes strongly bonded interfaces, steadily increasing the elastic modulus and hardness. Notably, the average friction coefficients decrease from 0.515 for the pure resin to 0.450 for the composites when the filler content reaches 7%, indicating a significant solid lubrication effect. In contrast, adding just 1% nickel/iron phyllosilicate moderately improves wear resistance, elongation at break, and tensile strength. Furthermore, it was found that as the filler content increased, the weight loss rate was reduced by approximately 43.8%, while the residual char increased by 74.2%, significantly enhancing the thermal stability of epoxy composites at high temperatures. This study offers a promising approach to preparing self‐lubricated epoxy composites with favorable mechanical and thermal properties. Highlights: NiFePS was successfully synthesized via a facile two‐step self‐polymerization.Excellent mechanical properties of composites could be achieved with low content of NiFePS.The friction coefficient and wear rate were lowered remarkably.The friction mechanism was solid lubrication. [ABSTRACT FROM AUTHOR]

With the advent of 5G/6G for radar and space communication systems, various millimeter‐wave (MMW) components are rapidly innovated for multi‐functional, higher integrated and miniaturized solutions across diverse industries and applications. Polymer composites‐based additive manufacturing (AM), an advanced manufacturing technique, can manufacture MMW components with high fabrication resolution, intricate structural design, adjustable dielectric properties, and functionally gradient distribution characteristics. This paper outlines the state‐of‐the‐art polymer composite MMW components, their design, and manufacturing techniques. An integrated "material‐structure‐manufacturing‐performance" design conceptual framework of polymer composite MMW components is discussed in terms of material design, structure design, and process design. Moreover, multi‐functional polymer composite MMW structures focus on electromagnetic wave absorption and electromagnetic interference (EMI) shielding functions. Moreover, novel applications of MMW polymer composite components enabled by AM on radar/sensing, communication, enclosure, and miscellaneous applications are discussed. Furthermore, future perspectives and current challenges are identified to provide new insights into multi‐functional 3D‐printed MMW products, exploring new possibilities for next‐generation advanced MMW technology. Highlights: The 3D‐printed MMW components and additive manufacturing are reviewed.The integrated "material‐structure‐manufacturing‐performance" concept is introduced.3D‐printed MMW components are discussed on radar, enclosure, and miscellaneous applications.Future perspectives and challenges of 3D‐printed MMW components are addressed. [ABSTRACT FROM AUTHOR]

In the present study, a discrete layer model was established to explore the vibration performance of Functionally Graded Carbon Nanotube‐Reinforced Composite (FG‐CNTRC) open cylindrical shells with damping film embedded based on the first‐order shell theory. There are four configurations of stacking arrangements considered for FG‐CNTRC open cylindrical shells with damping film embedded. The equivalent structural parameters of the top and bottom FG‐CNTRC panels are generated by implementing the extended mixing rule. Governing equations are derived based on the Hamilton principle and solved with the Naiver solution. Subsequently, after verifying the validity of this paper's solution by comparing it with the published literature, a parametric elaborated investigation discloses the variation patterns of vibration performance of four FG‐CNTRC open cylindrical shells with damping film embedded. The conclusions of the study can be used as a useful guide about open cylindrical composite shell structures with the design of high strength and damping. Highlights: Discrete layer vibration model was bulit based on first‐order shell theory.Vbration performance of FG‐CNTRC open sandwich shells was studied.Variation patterns of frequency and loss factor was disclosed. [ABSTRACT FROM AUTHOR]

This paper investigated the dispersion of silica exhibiting different specific surface areas in nitrile rubber (NBR) matrices and the interactions between fillers, filled rubber, and rubber networks by regulating the aggregate size. To better characterize and leverage the filler network structure, a comprehensive analysis was conducted using linear and nonlinear rheological tests based on the equilibrium solvation theory and pipe models. The results demonstrated that the incorporation of fillers formed an island‐like network structure. With high specific surface area, the concurrent use of high and low specific surface area silica fillers improved the filler‐rubber interactions and hindered filler‐filler interactions, decreased the filler aggregate size, and enhanced the dispersion. Furthermore, we analyzed the mechanism of the filler network structural enhancement and its relationship with the specific surface area by regulating the filler ratios to adjust the polymer size. Highlights: Control of Filler Network Structure: Ratio adjustment strengthens interactions.Large silica surface enhances F‐R interaction, small surface improves dispersion.Mixing ratios favor robust filler interconnection or dispersion.Reveals strong correlation of filler network strength with F‐F interactions.Highlighted effective eco‐friendly means of adjusting filler Mixing ratios. [ABSTRACT FROM AUTHOR]

Carbon Fiber Reinforced Polymers (CFRP) is one of the ideal materials in the field of automotive lightweight. As one of the traditional manufacturing processes of CFRP, autoclave process has long production time, high cost and complicated operation. To overcome these shortcomings, deep drawing can be used for CFRP forming. It has the advantages of stable product quality, good repeatability, low cost, simple operation and can produce parts with complex shapes. In this paper, the influence of lay‐up sequences on the drawability of cylindrical parts was studied by using self‐made deep drawing device. The results showed that among the four lay‐up sequences [0]°12, [0/90]°6, [0/90/45/‐45/90/0]°S and [15/30/....../180]°, the [15/30/....../180]° lay‐up parts had excellent deformation coordination ability due to less angular variation in the fiber direction, and the maximum depth of 21.99 mm could be obtained. Due to the influence of wrinkles, the thickness of [15/30/....../180]° parts increased at the die corner and side wall. The thickness decreased at the flange, punch corner and bottom due to the compressive pressure. In addition, [15/30/....../180]° lay‐up parts benefited from the high level of in‐plane isotropy of the helicoidal structure, it had the fewest forming defects. The resin poor areas and resin rich areas were less and no fiber cracks were found. Highlights: Investigated the influence of lay‐up sequences on the drawability of CFRP.The forming depth of [15/30/....../180]° parts was 21.99 mm.[15/30/....../180]° lay‐up parts had the best drawability.No cracks were found on the [15/30/....../180]° part. [ABSTRACT FROM AUTHOR]