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Vinylester-glass fiber composites have a wide scale of applications, however the combination between multiple fillers can cause some disadvantages due to complicated processing, high cost and incompatibility. This paper presents a novel trial for filling commercial vinylester (VE) resin with glass fiber (GF), as one filler component, in dual directions to prepare water pipe composite using the continuous winding technique, for the first time. 10% to 25% VE-GF composites were prepared with distributing GF in axial and hoop directions. The composites were cured via in-situ polymerization; the crosslinked network is occurred between catalyst and unsaturation sites in prepolymer. All concentrations show stability in all stages of thermal degradation, compared with blank VE; the more stable composite is 25% VE-GF. GF filled in axial and hoop directions enhanced the mechanical strength of both axes. The improved concentration (20% VE-GF composite) increased axial tensile strength and hoop tensile strength respectively to 32 MPa and 51 MPa, compared with 22 MPa and 42 MPa for blank VE. Furthermore, this concentration enhanced the strengths of surface harness and pull off from 39 BHC and 2.2 MPa to 46 BHC and 5.3 MPa, respectively. The 25% VE-GF composite decreased these values, but still higher than blank. GF improved the resistance of vinylester toward water absorption in different immersion conditions, especially the 25% VE-GF composites. The filling direction doesn't affect the composite stability. As a key issue for sustainable applied polymer composites, the proposed technique presents stable and low cost composite with one filler type, as physically, thermally and mechanically stable water pipe system. [ABSTRACT FROM AUTHOR]

Magnesium borate ceramics have several advantages such as light weight, high-temperature resistance, and low thermal conductivity. However, the poor mechanical properties of magnesium borate ceramics limit their further application. In this study, a combination of dry preparation and low-temperature sintering was proposed for the preparation of fiber-reinforced magnesium borate ceramics (SDHs) made from MgO, H 3 BO 3 , and glass fibers. The results from this study confirmed that the SDHs have a low thermal conductivity (0.286–0.677 W m−1 k−1) at 200–800 °C while maintaining a certain cold modulus of rupture (23.83–71.95 MPa). The insights gained from this study may be useful for heat preservation and partial load bearing applications. [ABSTRACT FROM AUTHOR]

The fiber hybridization in high-strength composites is one of the most researched strategies to enhance their limited toughness. In this work, hybrid composites at laminate level by stacking together plies of carbon and glass fiber were prepared using fused filament fabrication (FFF) technique. The large void content and the poor adhesion between layers attributed to this technology are overcome by the addition of an optimized thermo-pressurized treatment. The analysis of post-processing temperature effects on the microstructural, thermal and interlaminar properties of additive manufactured hybrid composites, revealed a progressive porosity reduction preserving the dimensional accuracy. The enhancement of mechanical properties is due to different contributions that occurred during post-processing: (i) drying effect, which reduces the plasticization of the composites; (ii) improvement of interface adhesion due to the miscibility of polymers; and (iii) significant porosity reduction (below 1 %). This work opens a wider space of possibilities, since FFF allows more complex designs than traditional composite manufacturing, and additionally provides an approach to promote molecular diffusion at the interface, which is the most critical region of FFF parts. [ABSTRACT FROM AUTHOR]

[Display omitted] This work evaluates several mechanisms of separation of surfactant-stabilized emulsified water droplets from diesel fuel using high surface area (50–370 m2/g) and high porosity (>90 %) filter media fabricated by combining aerogels and glass fiber mats. Specifically, high surface area, porous gels of syndiotactic polystyrene (sPS) and silica are developed inside glass fiber mats via dip coating in corresponding sol followed by sol–gel transition. The resultant materials are supercritically dried to obtain aerogel-coated separation media. The abundant meso- and macropores of the aerogel network and the different surface energy of sPS and silica produce cooperative functioning of the mechanisms of size exclusion, coalescence filtration, surfactant adsorption, and volumetric water absorption for removal of emulsified water droplets from ultralow sulfur diesel fuel under continuous flow conditions. The role of each separation mechanism is elucidated in this paper. The results reveal high water separation efficiency of ∼92 % compared to ∼30 % for the glass fiber mats. [ABSTRACT FROM AUTHOR]

Strong and conducting glass fibers are produced from reduced graphene oxide and soda-lime-silica (rGO/SLS) glass by a novel process of cladding drawing. GO nanosheets are bound to the SLS glass particles through an electrostatic assembly and are well distributed in the hot-pressed rGO/SLS bulk composites. These bulks are subsequently BN-cladded, from which rGO/SLS fibers are drawn. Results confirm the rGO sheets are well dispersed inside the fibers and become wrinkled due to the contraction of glass matrix while cooling. Mechanical properties of as-prepared fibers have been greatly improved, with tensile strength two times that of pure SLS fibers. As rGO concentration increases, a conducting network of rGO sheets forms along the fibers, which can survive intensive wear. Thanks to the wrinkled configuration of rGO sheets, the conductivity of the composite fibers is extremely sensitive to temperature, nearly 25 times that of flat rGO sheets, making the fibers potential built-in temperature sensors. Image 1 • "Cladding drawing" is employed for fabricating rGO/SLSGFs with rGO sheets wrinkled and well dispersed in the glass matrix. • rGO/SLSGs are significantly strengthened by rGO sheets, and become conducting due to the conducting nature of rGO. • Wrinkling of rGO sheets inside the glass fibers bestows rGO/SLSGFs with giant thermosensitivity. [ABSTRACT FROM AUTHOR]

• Custom-built 3D weaving machine was used to weave 3D spacer glass fiber fabrics. • PU foaming was directly performed in the vacancies of 3D woven I-beam composites. • Up to 43 % compressive modulus increase was obtained via in-situ PU foaming. • Energy absorption was increased in LD-PUFFIC by 173 % under three-point bending. • Post-mortem mechanical test samples were monitored by fractography. 3D weaving of I-beam structures can potentially create delamination- and joint-free structures, expanding their use in engineering applications compared to metal or traditional laminated composite beams. In addition, polymeric foams can be utilized to fill the vacancies between the web and the flanges of I beams, improving the mechanical characteristics and the structural integrity with little to no weight penalty. Moreover, interposing an adhesive layer between the I beam and the foam structure can result in a more effective bonding which intensifies the structure's robustness. In this study, high-performance I-beam composites were produced by combining polymeric foams with 3D woven glass fiber composites. Low- and high-density polyurethane foams were successfully inserted between the web and the flanges of 3D woven glass fiber composites manufactured by the vacuum infusion process using the free-rise foaming method. Samples with adhesive films were also produced to assess and compare their effectiveness with the composites made solely of polyurethane foam and I beam. The increases in energy absorption capacity and compressive and flexural properties were analyzed under compressive and flexural (three-point bending) loading. The obtained results indicate that structural integrity under bending can be substantially improved with the in-situ foaming supported by adhesive layers. [ABSTRACT FROM AUTHOR]

• The Fickian law is a good fit for the water adsorption behavior of PPS/GF composites. • The mechanism of hydrothermal aging of PPS/GF composites was revealed by discussing matrix, fiber and interface. • The strength retention rate of hydrothermal aging of PPS/GF composites was predicted using the Arrhenius formula-based analytical model at different temperatures. In this paper, hydrothermal aging behavior of short-cut glass fiber reinforced polyphenylene sulfide composites (PPS/GF) were studied. The water adsorption behavior can be well described by Fickian law and have strong correlation with mechanical properties. The microbond test joint with morphology observation by scanning electron microscope (SEM) and separate evaluation about matrix, fiber and interface unveil that the mechanism of hydrothermal aging of PPS/GF composites and deterioration of interface play the dominant role in degradation of macroscopic mechanical properties. Finally, the life and mechanical properties prediction model of the hydrothermal aged PPS/GF composites were established based on the collected aging data and Arrhenius formula. [ABSTRACT FROM AUTHOR]

• Enhancing drilling responses of glass epoxy composite is explained. • Impact of graphene in the improvement of précised machining is described. • A spinning 4-component dynamometer is used to measure the thrust force and torque. • The ANOVA technique is used to achieve the influence of parameters on responses. • Surface morphology are analyzed to check the effect of graphene nanoplatelets. The objective of the present study is to explore the influence of graphene nanoplatelets having various wt%, spindle speed (SS), and feed rate (FR) on damages caused due to drilling of glass fiber reinforced polymer (GFRP) laminates. The findings showed that when the concentration of graphene grows up to 0.25 wt%, it enhances the mechanical properties of the composite. After that, it starts to decrease. Experiments proved that interlaminar shear strength (ILSS), flexural strength, and tensile strength of the graphene-embedded (0.25 wt%) composite rose by 18.49 %, 25.15 %, and 14.79 %, respectively, as compared to neat GFRP composite. A minimum surface roughness (2.1393 µm), thrust force (622.62 N), torque (2.0155 Nm), entry delamination factor (1.1556), and exit delamination factor (1.2218) were attained in 0.25 wt% graphene-embedded GFRP composite. An increase in SS and a reduction in FR led to optimizing the composites' machining performances. Lastly, FESEM was used to examine the damage on the drilled surfaces. [ABSTRACT FROM AUTHOR]

The possibility of adopting glass-fiber reinforced polymer (GFRP) composite bars in tunnel segments as a substitute of the traditional steel reinforcement has been demonstrated. Nevertheless, this application requires a curvilinear shape for the reinforcement, and thus a different production process and rebar geometry. The aim of the paper is the experimental evaluation of the physical and mechanical properties of non-conventional GFRP rebars. The test procedures and obtained results are highlighted and compared with the acceptance criteria available for straight pultruded rebars. Finally, the presented outcomes show the suitability of GFRP non-conventional bars as reinforcement for precast concrete segments in tunnel applications. [ABSTRACT FROM AUTHOR]

Fiber length is believed to be an important variable in determining various toxicological responses to asbestos and other elongate mineral particles. In this study we investigated screen collection characteristics using monodisperse-length glass fibers (i.e., 11, 15, 25, and 53 µm in length), to better understand the collection of fibers with different lengths on screens with different mesh sizes. A well-dispersed aerosol of glass fibers (geometric mean length ~ 20 µm), generated by vortex shaking, was fed directly into the Baron Fiber Length Classifier, in order to produce monodisperse length fibers. With nylon mesh screens (10, 20, 30, 41 and 60 µm mesh sizes), the screen collection efficiency was measured using an aerodynamic particle sizer. As the screen mesh size decreases from 60 µm to 10 µm, the screen collection efficiency for 53 µm fibers increases (from 0.3 to 0.9) while 11 µm fibers exhibited a collection efficiency independent of screen mesh size. The collection efficiency for the longest fibers was found to be nearly constant for aerodynamic diameters 1–4 µm for screens 20 and 30 µm, but to rise significantly at aerodynamic diameters larger than 4 µm. For the 20 µm screen, the collection efficiency for fibers with lengths > 20 µm is a factor of two to five larger than that for spherical particles with the same aerodynamic diameter. We believe that fibers are collected on the screen primarily by interception below 4 µm in aerodynamic diameter, and by impaction above 4 µm. This study represents a fundamental advance in the understanding of the interaction of screens with a fibrous aerosol. [ABSTRACT FROM AUTHOR]

A series of graphene oxide (GO) with various oxidation degrees were synthesized in this work and then grafted onto the surface of glass fiber fabric (GFf), and subsequently a resin infusion process was engaged in the fabrication of GFf/epoxy laminated composites. Interlaminar and interfacial properties as well as interlaminar microstructure of laminated composites were investigated in detail. Results showed that various oxygen-containing functional groups on the GO surface due to oxidation degrees endowed GO with different dispersion states in composites and strengthening/toughening efficiency, thus greatly influenced composites' interlaminar and interfacial adhesion. Also, the desorption and diffusion of GO from the fiber surface into matrix-enriched interlaminar region during the resin infusion process were evidenced. Making use of a moderate weight ratio of oxidation agent (KMnO 4)/graphite (2:1), the optimal oxidation degree of GO was achieved for reinforcing fiber/matrix interface and matrix-enriched interlaminar regions. Under this case, the interlaminar shear strength and work of fracture of resultant composites were raised by 28.2% and 138.3%, respectively; storage moduli in glass regions and at the beginning of rubbery regions were enhanced by 22.3% and 104.5%, respectively; the significantly fiber/matrix interfacial adhesion and glass-transition temperature were obtained, compared with those of the control sample. This work provides a guiding strategy for optimizing strength and toughness of fiber-reinforced composites by regulating GO oxidation degrees. [Display omitted] • Tailoring GO oxidation degree to optimize structure and properties of composites. • GO was desorbed and diffused from the fiber surface into interlaminar region. • Strengthening/toughening mechanisms of GO for laminated composites were analyzed. [ABSTRACT FROM AUTHOR]

[Display omitted] • The use of MPCM in light transmitting cementitious composites was investigated. • A novel light transmitting thermal energy storage cementitious composite was designed. • The thermal energy storage capacity of cementitious composites increased with MPCM. • The usage of MPCM remarkably decreased the thermal conductivity of composites. • Significant amount of light transmittance was obtained with plastic optical grids. The energy utilization for artificial lighting, cooling, heating, and air conditioning in buildings results in the release of greenhouse gases and causes climate crises. In this regard, a novel light-transmitting cementitious composite (LTCC) was developed by substituting microencapsulated phase change material (MPCM) to reduce the building energy utilization via transmitted light through the composite and improve the solar thermal energy efficiency. The cementitious matrix is produced with cement, kaolin, silica sand, water, superplasticizer, adhesive polymer, glass fiber, different ratios of MPCM, and plastic optical grids to let inward sunlight transmittance. The current study thoroughly investigates the characteristics of light-transmitting composite, including MPCMs, via physico-mechanical, chemical, microstructural, thermal, light transmittance and solar thermoregulation tests. The thermal conductivity of the composite with 0 wt% MPCM decreased from 1.09 W/mK to 0.96 W/mK with 15 wt% MPCM addition. Incorporating 10 wt% of MPCM reduced the 28 days-compressive strength of specimens by almost 28 % due to the lower strength and density of microcapsules, as well as the voids formed by damaged MPCMs. On the other hand, the incorporation of MPCM did not dramatically affect the flexural strength of the cementitious composite. DSC analysis results revealed that the composite containing 15 wt% MPCM shows a latent heat of fusion of 14.6 J/g with a melting point of 17.65 °C. FTIR analysis disclosed that MPCM maintains its chemical structure in the composite. Composite slabs exhibited up to 12.4 % artificial light transmittance, which would translate to a considerable increase in the lighting efficiency of commercial and residential buildings. Thermoregulation performance test under ambient conditions indicates that the specimen containing 15 wt% MPCM can provide a cooler room temperature for 6.5 h when the room or surface temperatures increase above 21–23 °C, and a warmer room when the temperature decreases below these temperatures. The findings of the current study can be applied to enhance thermal energy saving and artificial lighting efficiency in buildings that inspire the design of environment-friendly constructions. [ABSTRACT FROM AUTHOR]

• Marine glass fiber reinforced composites are drilled. • The effects of seawater treatment on the increase in drill-induced delamination failure are investigated. • Different material thicknesses (6, 8, and 10 mm) and immersion times (20, 40, and 60 days) were examined. • The significance of spindle speed as an input deciding parameter is emphasized. • The increase in peel up delamination failure seen after 60 days of seawater immersion was 290.22, 305.86 and 250.81 %. • The increase in the push down delamination failure seen after 60 days of seawater immersion was 69.48, 76.38 and 64.28 % in 6, 8 and 10 mm composites. Composite materials, particularly glass fiber reinforced polymer (GFRP) composite, have established a strong presence in the marine industry. Its marine applications range from constructing massive naval vessels to constructing simple fishing boat hulls. Previous research has established that seawater aging has a detrimental effect on the physical and mechanical properties of GFRPs. Additionally, drilling composites are known to cause delamination damage, resulting in a high failure rate. Since composite components are assembled with fasteners, drilling operations are unavoidable. Thus, the current study examines the effect of seawater aging at a macroscopic level while considering the input parameters spindle speed and feed and material thickness and the response variables as peel-up and push-down delamination damages. The result indicated higher failure rates in the seawater-treated composites than in untreated composites. The maximum damages were seen in the 60 days of immersed composites, wherein the peel-up delamination damage increased by 290.22, 305.86, and 250.81 %, and the push-down delamination damage increased by 69.48, 76.38, 64.28 % in 6, 8 and 10 mm composites, respectively. The combinational effect of seawater degradation of GFRP composites and the damages caused by the cutting forces (function of speed and feed) attribute to the failure rate increase concerning the drilling-induced delamination damages in the composites. In addition to investigating the effect of seawater immersion on damages, the study also provides the regression analysis-based mathematical model having high goodness of fit and predicting capability to determine the damages for the given values of input variables. [ABSTRACT FROM AUTHOR]

• The functional groups in the chemical structure of the composites were identified. • The degree of crystallinity was determined by differential scanning calorimetry (DSC). • The annealing contributes to an increase in crystallinity. • The size of polypropylene spherulites was determined by optical method. This study presents the results of examinations of polypropylene-glass fiber composites. Polypropylene matrix composites containing 30% and 50% glass fiber were tested. Part of the material was subjected to heat treatment consisting of annealing. Depending on how polymeric materials are obtained, their physical and mechanical properties change over a wide range. Their understanding and interrelation between each other depend on accurate quantitative structural assessment at both the chain and elemental cell microstructural levels and the supramolecular level. FTIR-ATR technique was used to identify the characteristic functional groups present in the chemical structure of polypropylene and composites based on its matrix. Structure analysis at the supramolecular level was performed using differential scanning calorimetry (DSC) and temperature microscopic examinations. These examinations allowed for the evaluation of thermal parameters such as melting point and crystallization temperature of the polymer matrix in the composites studied. Furthermore, by analyzing the values of thermal effects determined using the DSC method, it was possible to determine the degree of crystallinity. A deeper understanding of the interdependence between the structure and properties of polymers allows to predict the characteristics of the final product and enables optimization of technological processes. [Display omitted] [ABSTRACT FROM AUTHOR]

The low water permeability of reduced graphene oxide (RGO) membranes limit their wide applications in water treatment. Herein, a new route to fabricate a lignin nanoparticles-intercalated RGO composite membrane with high flux is reported. The addition of alkali lignin (AL) not only contributed to the reduction of graphene oxide (GO) in the hydrothermal reduction process, but also intercalated between RGO nanosheets. The AL/RGO nanosheets were further cross-linked with polydopamine (PDA) to stabilize the interlayer structure and finally assembled onto a glass fiber (GF) membrane by a vacuum filtration process. The AL/RGO@PDA membrane shows a large pure water flux up to 2410.3 L/m2 h, which increased by 297.3% than that of the RGO composite membrane (810.7 L/m2 h) without nanoparticles intercalated. Even after 10 cycles, the AL/RGO@PDA membrane remained high separation efficiency (above 99.10%) for n-hexadecane emulsion. In addition, such a membrane maintained the original performance at high temperature (98 °C) and in highly corrosive environments (pH=1, pH=14). Overall, this study provides a facile and eco-friendly method to fabricate high flux RGO composite membrane, showing promising application for water purification and separation. [Display omitted] • Alkali lignin can avoid excessive reduction of graphene oxide. • The intercalated lignin nanoparticles increased the flux of the composite membrane. • The membrane exhibited high separation efficiency and flux by gravity-driven. • The membrane can maintain stability under multi-kinds external stimulations. • The membrane showed excellent antifouling property and reusability. [ABSTRACT FROM AUTHOR]

GFRP (Glass Fiber Reinforced Polymer) rods have found a wide range of applications in building structures as reinforcement of concrete bearing elements. In no time on the market appeared a few producers who are offering a wide assortment of diameters. In this paper, applied test procedures and their results for GFRP rods are presented. Rods made by three manufacturers, with declared diameter 12 mm, have been analyzed. The tensile strength, elasticity modulus and ultimate limit strain, based on the static tensile test, were compared. These resultants were compared with tensile strength obtained for widespread use reinforcement steel AIIIN. Different results of composite rods destroying process are discussed. It worth stressing the great discrepancy between the declared and real diameter of tested rods, which may result in an inability to simple conversion between conventional steel reinforcement to composites in structural elements. [ABSTRACT FROM AUTHOR]

In this research, friction coefficients of composite materials such as gear fiber reinforced plastic (gear fiber) and glass fiber reinforced plastic (glass fiber) are investigated and compared. In the experiments, gear fiber and glass fiber slide against different austenitic stainless steels such as stainless steel 201 (SS 201) and stainless steel 301 (SS 301). Experiments are carried out at low loads 2, 4 and 6 N, low sliding velocities 0.2, 0.4 and 0.6 m/s and relative humidity 70%. The obtained results reveal that in general, friction coefficient of gear fiber and glass fiber increases with the increase in normal load and sliding velocity. Results show that friction coefficient of glass fiber-SS 201 pair is the highest and gear fiber-SS 301 pair is the lowest within the observed range of normal load and sliding velocity. On the other hand, it is found that friction coefficient of glass fiber-SS 301 pair is slightly higher than that of gear fiber-SS 201 pair. During the running-in process, friction coefficient of gear fiber and glass fiber steadily increases with the increase in rubbing time and after certain duration of rubbing, it remains constant regardless of the counterface material. The obtained results reveal that for the observed range, the influence of normal load on the frictional properties of gear fibe and glass fiber is greater than that of sliding velocity. At identical operating conditions, the magnitudes of friction coefficient of gear fiber and glass fiber are different depending on normal load, sliding velocity and counterface material. [ABSTRACT FROM AUTHOR]

• Microencapsulated PCM (mPCM) was used at 2.5, 5 and 7.5 wt% in glass fiber reinforced gypsum plasterboard (GP). • GP with 7.5 wt% mPCM has latent heat of 16.7 and 16.6 J/g at melting and solidification of 11.90 °C and 12.09 °C, respectively. • mPCM-GP room showed 3 °C lower temperature compared to the reference room. • mPCM-GP can be considered as an effective energy-saving material in buildings. A comprehensive study involving the fabrication and characterization of gypsum plasterboards combined with microencapsulated phase change material (mPCM) is introduced to evaluate their benefits regarding thermoregulation management and energy saving performance in buildings. For this purpose, the produced new type of gypsum plasterboard was subjected to the detailed chemical, morphological, mechanical, physical and thermal tests. The gypsum plasterboard incorporated with mPCM (7.5 wt%) and reinforced by glass fiber has latent heat capacities as high as 16.7 and 16.6 J/g at onset melting and solidification temperature of 11.90 °C and 12.09 °C, respectively. TGA analyzes revealed high thermal stability of gypsum plasterboard up to about 140 °C. Outcomes exhibited that mPCM-gypsum plasterboard can substantially diminish cooling load of a building during the daytime even at the high room temperature and offer decline in heat necessity of a house during night-time. During peak room temperature hours, the mPCM-gypsum plasterboard achieved 3 °C lower temperatures than the reference room, and it provided a cooler room temperature for about 7 h during the daytime while a warmer temperature of 0.3 °C was achieved at the cold weather. As a result, the produced gypsum-based composites can be considered as an energy-saving and indoor temperature regulating material in buildings. [ABSTRACT FROM AUTHOR]

In recent years, natural fiber as a green and renewable resources have attracted much attention to be used as reinforcement in composites. The aim of this work is to assess mechanical properties and durability in harsh environments of epoxy-based flax and glass bio-hybrid fiber reinforced plastics (bio-HFRP) composites. With the same fiber mixing ratio, the flexural and dynamic mechanical properties of the bio-HFRP composites were studied by changing the stacking order. The pure flax FRP and bio-HFRP composites were exposed to hygrothermal at 20 °C, 40 °C, and 60 °C for 28 days, respectively. The water absorption and diffusion capacity, the bending and shear properties were analyzed. Compared with the pure flax FRP, the flexural strength of G 2 F 2 s group sample was increased by 2.2 times. When exposed to the hygrothermal environment, flexural strength loss rate of the G 2 F 2 s group sample is only reduced by 4.35%, 9.00% and 11.51%, and its flexural modulus decreases 15.48%, 15.90% and 23.89%. It shown that the addition of glass fiber effectively improves the water absorption of flax fiber composites. Hybridization of flax fibers with glass fibers was a practical approach to enhance FRP laminates in hygrothermal environmental conditions after synthesizing the stacking sequence, mechanical properties and aging resistance. [ABSTRACT FROM AUTHOR]

Frictional characteristics of glass fiber reinforced polymer (GFRP) composites are of technological interests for reducing wear in circumstances where they are applied. Graphene oxide (GO) is one 2D nanomaterial with an excellent lubricating effect. However, no work has been reported yet on the effects of GO coating on the frictional characteristics of GFRP composites. In this work, GO was grafted on GFs by a surface treatment method via silane coupling agent. Uncoated and coated unidirectional GF reinforced epoxy composites were prepared using a hot press process. The frictional characteristics of GF reinforced composites were investigated in two directions parallel and perpendicular to fiber direction by the pin-on-disk method under the pressure of 5–30 N at the disk rotating speed of 50–200 rpm. The results showed that the frictional stability was greatly improved by grafting GO on GFs. The friction coefficient of GO-coated glass fiber reinforced polymer (GO-coated GFRP) composite was generally lower than that of the GFRP composite under a low pressure of 5 N and showed the lowest average friction coefficient of about 0.10 at the rotating speed of 100 rpm in the direction parallel to the fiber alignment. For the raw glass fiber reinforced composite, the friction coefficient is high under low pressures at low rotation speeds while this tendency is inverse for the GO-coated GFRP composite. In addition, the anisotropy of the friction characteristics is not obvious under low pressures but becomes obvious at high pressures for both GFRP and GO-coated GFRP composites. [Display omitted] [ABSTRACT FROM AUTHOR]

This experimental study focuses on the development of an amphiphilic sizing agent to improve the interfacial adhesion and the mechanical properties of short glass fiber (GF)/polypropylene (PP) composites. To solve the critical compatible issue between the hydrophilic GF and the hydrophobic PP, we strategically utilized the reversible addition-fragmentation chain-transfer (RAFT) polymerization to self-assemble and synthesize an amphiphilic sizing agent. This surfactant-free sizing agent can create hydrogen bonds and electrostatic adsorption on GF surfaces and meanwhile can form molecular entanglements, alkyl cations, and σ-π conjugates with PP matrix. The FT-IR analysis shows that a large number of hydrogen bonds are formed on the sizing agent-GF interface. Additionally, the SEM micrographs of the composite fracture surfaces demonstrate strong interfacial compatibility between the sized-GF and the PP matrix. Comparing with the neat GF/PP composites, the tensile and flexural strength of the sized-GF/PP composites are increased by 25.8% and 33.1%, respectively. Their tensile strength and young's modulus are in close agreement to the analytical calculations. In short, this paper presents a new RAFT-based methodology to develop the amphiphilic sizing agents that are able to improve the interfacial compatibility of GF/PP composites and also can be transferred towards real applications for enhancing the mechanical properties of fiber-reinforced composites. Schematic diagram showing the mechanism of the PBAMD sized-GF/PP interface interaction. [Display omitted] [ABSTRACT FROM AUTHOR]

In this study, the electromechanical properties and strain monitoring behavior of graphene-coated glass fiber reinforced epoxy (GGFRE) composites were investigated. Glass fabrics were first coated with 2 wt% graphene dispersions using a blade coating method and composites of these graphene-coated glass fabrics were manufactured using vacuum resin infusion. As-prepared GGFRE showed an increase in normalized resistance (ΔR/R 0) by 4.46%, 10.5%, 11.07% and 11.27% proportional to the applied cyclic tensile forces up to 2000N, 3000N, 4000N and 5000N, respectively. The corresponding gauge factors were calculated to be 14.56 ± 1, 13.32 ± 1, 11.23 ± 0.5 and 8.69 ± 2, respectively. It was also observed that under cyclic tensile loadings at 2000N, ΔR/R 0 values were consistent within 11 cycles indicating a reliable sensing performance. The integration of graphene into the composite has shown to decrease the tensile strength as well as flexural strength and flexural modulus by 26%, 37% and 39%, respectively. This drop is believed to be caused by the lower fiber volume content in the GGFRE compared to that of the neat glass fiber composite and the ineffective interfacial interaction between the glass fiber and the graphene dispersion. The piezo-resistive behavior indicated by GGFRE along with their scalable manufacturing method suggest them as promising potential candidates for strain sensing applications. [Display omitted] [ABSTRACT FROM AUTHOR]

A novel 3D printing strategy for continuous glass fiber reinforced polylactic acid (CGF/PLA) composites was proposed. CGF/PLA filament was prepared by a melting impregnation device, and then CGF/PLA filament was directly supplied to the self-modified 3D printing device. The impregnation process was optimized systematically, and the fiber content reached up to 45 wt%. A specific compatibilizer was used and the amount of compatibilizer was optimized to enhance the interfacial bonding between fiber and polymer. The effects of printing parameters such as nozzle diameter, edge width, layer thickness, printing speed and temperature on the mechanical properties and microstructure of the final printed products were studied. The flexural strength and flexural modulus of the printed products reached 312 MPa and 21.5 GPa, respectively. The fabrication strategies proposed in this study can provide a low-cost and high-strength method for the industrial application of 3D printed continuous fiber reinforced thermoplastic composites. [Display omitted] • 3D printing of continuous glass fiber reinforced polylactic acid composites with a high efficiency and low cost strategy. • The printed composites exhibited great flexural strength and fiber content up to 45 wt%. • Impregnation and Printing Parameters were optimized to provide a foundation for future industrial application. [ABSTRACT FROM AUTHOR]

In this study, changes in the properties of neat, carbon and glass fiber reinforced polycarbonate via high dose rate gamma irradiation were investigated. Irradiations were carried out at dose rate of 737 Gy/h. Specimens were irradiated up to four different doses which were 10, 25, 50, 75 kGy. Total irradiation doses, irradiation dose, type and content of the additives were parameters used in estimation of radiation stability of specimens. Tensile testing, dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), attenuated total reflectance-Fourier transfor m infrared spectroscopy (ATR-FTIR), spectrophotometric analysis (for yellowness index) and scanning electron microscopy (SEM) were techniques applied for characterization of specimens. According to the results, End point criteria, which is specified for polymers used in radiated areas, were not observed in specimens by 75 kGy irradiation. Carbon fiber addition yielded more linear dependence than glass fiber regarding tensile strength values with respect to fiber content. Glass fiber and carbon fiber filled polycarbonates could be safely used in radiated areas up to a time at which total absorbed dose reaches to 75 kGy. [Display omitted] • 10% carbon fiber loaded composites exhibited the best stability. • YI of GF reinforced composite were lower than that of neat PC at 75 kGy acting as scavenger of phenoxy and phenyl radicals. • GF and CF filled polycarbonates could be safely used in radiated areas up to a time at which total absorbed dose is 75 kGy. • 75 kGy irradiation did not deteriorate the surface of composites. [ABSTRACT FROM AUTHOR]

• Mechanical properties of UP/nanoclay and UP/nanoclay/fiber composites are studied. • Effect of EB irradiation on mechanical properties of composites is investigated. • Effect of irradiation on composites is studied using FTIR spectroscopy. • Nanoclay enhanced both mechanical and radiation resistance properties of polymer. • The composites had desirable properties for applications with radiation exposure. Following our previous work on morphology, corrosion resistance and thermal properties of unsaturated polyester (UP)/nanoclay composites, the effect of electron beam (EB) irradiation on mechanical properties of UP/nanoclay composites with various nanoclay contents is investigated in this work. Moreover, influence of EB irradiation with doses of 100, 500 and 1000 kGy on tensile properties and hardness of nanocomposite was examined. FTIR spectroscopy was employed to examine the effect of irradiation on chemical structure of polymer. EB irradiation up to 500 kGy led to the improvement of tensile strength and hardness of the samples. The best mechanical properties were observed for the nanocomposite with 1 wt.% nanoclay content. As the selected nanocomposite, UP/nanoclay(1 wt.%) composite was reinforced by carbon and glass fibers and the effect of EB irradiation on the mechanical properties of the prepared UP/nanoclay/fiber composites was studied. When compared to the fiber-reinforced UP without nanoclay, presence of nanoclay particles in UP/nanoclay/fiber composites resulted in the better mechanical properties and higher radiation resistance. Hence, the UP/nanoclay/fiber composite with proper amount of nanoclay has been shown to be a dependable choice for structural applications in which the material is exposed to ionizing radiations. [ABSTRACT FROM AUTHOR]

Polylatic acid (PLA) and PLA foams show a promising prospect for replacing the traditional petroleum-based polymers and foams. However, PLA shows poor ductility, thermal stability and foaming ability, and its application is significantly limited. Herein, silane-modified glass fibers (m-GF) were adopted to improve the mechanical properties, thermal stability, and foaming ability of PLA. PLA/m-GF composites with different GF contents were firstly prepared by twin-screw compounding. Microscopic morphology analysis showed that silane-modified GF has a good bonding with PLA matrix, and increasing GF content led to slight decreased of GF length. Mechanical testing showed that GF led to simultaneously enhanced strength, rigidness, and toughness. The higher the GF content is, the more obvious the reinforcement effect is. With 20 wt% GF, the PLA/m-GF composite shows almost 2-fold enhanced strength and rigidness, and more than 3-fold enhanced impact toughness than the pure PLA. The outstanding mechanical properties arises from the strengthening effect of the GF network skeleton that shows good bonding with PLA matrix. Thermal analysis showed that GF led to increased heat deflection temperature but reduced melt flow index of PLA. Foaming experiments showed that GF can dramatically improve the foaming ability by increasing expansion ratio and refining cellular morphology. Microcellular PLA/m-GF foam with an expansion ratio of up to 20-fold and cell sizes less than 10 μm was achieved. Thus, the strong PLA/m-GF composites and their foams show a promising future in preparing lightweight structural components used in many applications such as automotive and aircraft industries. Image 1 • Silane-modified glass fibers (GF) were incorporated to enhance polylactic acid (PLA). • GF led to simultaneously enhanced strength, rigidness and toughness of PLA. • GF increased the heat deflection temperature of PLA. • GF can greatly improve the foaming ability of PLA. • Low-density microcellular PLA/GF foams were prepared. [ABSTRACT FROM AUTHOR]

Composite materials are better and are used than other conventional structural materials because they offer superior performance, high specific strength and stiffness, excellent fatigue resistance, low weight and design flexibility. These above-mentioned properties have become the winning alliance that impels fibrous composite materials into new arenas. Glass Fiber/Epoxy Polymer Reinforced Plastic composites are widely used over other orthodox engineering materials in the Automobile and Aerospace industry owing to the improved properties. In the present work, an attempt has been made to study the properties of combination of unidirectional E-glass Fibers and carbon reinforced matrix (Bituminous coal tar + Epoxy) with an increase in weight proportions (wt%) of coal tar from 0 wt% till 10 wt%. The properties of cryogenically exposed Glass - Fiber Bituminous carbon coal polymer composites (GBCPC) are studied and compared with that of unexposed. The composites density was found to increase with bituminous coal tar in matrix. The Hardness, Ultimate Tensile Strength and Inter-Laminar Shear Strength of the composites witnessed an increase with greater matrix reinforcement wt% and after cryogenically exposure hardness and ultimate strength have witnessed an increase but Inter-Laminar Shear Strength shows phenomenological behavior, it can be due to micro cracks as well as delamination in the composites due to thermal residual stresses. The sliding wear test was conducted using Taguchi L16 method. The dry sliding wear of the cryogenically exposed specimen displayed higher resistance to wear. [ABSTRACT FROM AUTHOR]

We investigated the tailored electromagnetic interference shielding effectiveness (EMI SE) of polyester-matrix composites consisting of glass fiber textiles coated with multiwalled carbon nanotubes (MWCNTs) and exfoliated graphite nanoplatelets (xGnPs). The effects of various combinations of material parameters, including MWCNT length, xGnP size, MWCNT:xGnP weight ratio, host-substrate surface configuration of carbon nanomaterials (CNMs), and their amount coated per unit area, on the EMI SE were studied. The shielding mechanisms, namely, absorption, reflection, and multiple reflections, are discussed based on the underlying governing physics. EMI SE measurements showed that coating glass fibers with hybrid MWCNTs/xGnPs at 8/2 ratio yields EMI SEs higher than those of composites containing the same content of a single-type of CNM, ranging from 56.8 dB at 30 MHz to 35.3 dB at 1.5 GHz. Morphological studies showed that, upon placement on glass fiber surfaces, 1D fiber-like MWCNTs serve as interconnects that bridge the randomly oriented 2D platelet-like xGnPs to form an efficient plane shield of electromagnetic waves. [ABSTRACT FROM AUTHOR]