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Globally, the operational energy usage in buildings accounts for about 30% of the final energy consumption and 26% of the energy‐related emissions. In 2022, the building sector recorded 132 EJ in energy usage and 9.8 Gt of CO2 emissions. Energy‐intensive space heating and air conditioning play a significant role in these statistics, with slightly over half of US home energy usage attributed to them. Thus, energy‐efficient buildings, incorporating effective thermal insulation, are essential for addressing climate change. Fiberglass is the dominant insulation material used in US homes, comprising about 71% of installations. The paper discusses the fundamental aspects of heat transfer in fibrous insulation in general and fiberglass insulation in particular. The thermal performance of a fibrous insulation is characterized by an effective thermal conductivity, which combines conductive and radiative terms. The former represents heat conduction through the gas–fiber network and the latter the absorption and the scattering of thermal radiation by the fibers. The paper describes mathematical formulations for these terms and presents results showing the dependence of the effective conductivity on insulation density, fiber diameter, and temperature. The predicted values of the effective conductivity are found to be in good agreement with the measured ones. [ABSTRACT FROM AUTHOR]

A model is presented for calculating the electric field profiles of transverse modes in fibres. Using this model, the electric field propagation of transverse modes was calculated and compared in both bent and straight Yb and Ho fibres. Our simulations revealed that the field intensities of the modes did not consistently increase or decrease by bending as expected, but rather fluctuated as the bending radii of the fibres changed from 1 to 100 cm. Additionally, it was observed that at certain bending radii, the modes of the fibres became deformed and transitioned into higher modes. Furthermore, the extent to which the modes stretched towards cladding due to bending was calculated. To provide a more comprehensive analysis of the results and investigate the effects of the physical parameters of the fibres on the bent fibre modes, simulation results were presented for two different V numbers and core radii. [ABSTRACT FROM AUTHOR]

The main objective of the research is developed toward adsorption electronic devices (Interface material) with the performance examined by the physical, mechanical, and thermal properties of the E‐glass fiber reinforced with the epoxy composite and particulate dispersed into the matrix in partial fulfillment of tiny amount of aluminum powder particles and MWCNT. Composite membranes with 15 wt.% E‐glass fiber and 2 wt.%, 4 wt.%, and 6 wt.% fine aluminum powder particle concentrations were partially filled with 0 wt.%, 0.5 wt.%, and 1.0 wt.% MWCNTs. Vacuum lay‐up technique is used to create the better adhesive hybrid composite, which is then assessed of the characteristics of the materials. The maximum thermal conductivity of EAEM2 (E‐Epoxy, A‐Aluminum particle, E‐E‐glass fiber, M‐MWCNT) is 0.3057 W/mK. The tensile, bending, and impact strengths of EAEM1 composites are higher than those of EAEM2 and EAEM3 (average values of EAEM1 composites: 86 MPa, 123.33 MPa, and 90.66 J/m2). However, the Shore‐D hardness of EAEM3 is 95.33. The test findings demonstrate a significant improvement in thermal properties with minimal marginal decrements in mechanical capabilities when carbon allotropes are increased. The composite system's morphology (EAEM3) demonstrates a clustered distribution of aluminum powder particles in the matrix. [ABSTRACT FROM AUTHOR]

This work compares the tensile and fatigue behavior of unidirectional glass fiber/epoxy (GFRPs) and basalt fiber/epoxy (BFRPs) composites manufactured using vacuum-assisted resin infusion molding (VARIM). The tensile and fatigue tests are performed, and results show that both GFRPs and BFRPs have very similar tensile behavior, whereas BFRPs perform better than the GFRPs in terms of fatigue life and degradation of properties, showing about 75 MPa more fatigue limit. The S-N curve shows that BFRPs resist fatigue failure and stiffness degradation due to their better interfacial adhesion. Fractographic observations reveal fatigue failure mechanisms of both BFRPs and GFRPs. From the regression analysis performed, an S-N curve was fitted with a model available in the literature, and regression parameters were calculated. Dynamic mechanical analysis of both BFRPs and GFRPs was performed to evaluate parameters like glass transition temperature, storage modulus, and loss modulus. From the findings of this research, BFRPs may be recommended as a suitable alternative to GFRPs. Highlights • This article compares the tension-tension fatigue properties of unidirectional GFRPs and BFRPs. • From the research work, the authors found that BFRPs perform better than GFRPs under fatigue loading. • The stiffness degradation behavior of GFRPs and BFRPs are studied and compared. • Scanning electron micrographs of fractured samples are used to observe fatigue failure mechanisms. • Dynamic mechanical analysis (DMA) was performed to determine the storage modulus, loss modulus, glass transition temperature, and damping coefficient (tand) for both composites. [ABSTRACT FROM AUTHOR]

To investigate the real anchorage performance of basalt and glass hybrid fiber reinforced plastic (FRP) anchors in external corrosive environments. In this paper, a combination of experimental studies and finite element analysis was used. By carrying out pull‐out tests of basalt and glass hybrid FRP anchors under the synergistic effect of freeze–thaw cycles and alkaline environment, the effects of factors such as hole diameter, anchorage length, and mortar strength on their anchorage performance and durability were investigated. Critical corrosion time was introduced to determine the degree of corrosion of the anchor rods. After that, it combined with numerical simulation to reveal the degradation mechanism of the anchorage performance of hybrid anchors. The results showed that the best anchorage performance of basalt/glass hybrid FRP anchors was achieved when the hole diameter was 24 mm, the anchorage length was 175 mm, and the mortar strength was 45.5 MPa. The ultimate pull‐out load was up to 122.16 kN. When the time did not exceed the critical corrosion time, the ultimate load‐carrying capacity of basalt and glass hybrid FRP anchors increased by 9.3% compared to the uncorroded environment. Beyond the critical corrosion time, the ultimate load‐carrying capacity was reduced by 23.3% and the anchorage performance was degraded. In addition, the contact interface between the anchor and the mortar is the weak area of the anchoring structure, which should be focused on in the later design of the actual project. Highlights: Basalt/glass hybrid FRP anchors have good corrosion resistance.The anchoring performance of hybrid FRP anchors under the coupled environment is studied.Hole diameter and anchoring length have more influence on the anchor performance.The concept of critical corrosion time is put forward.The failure mechanism and coupling environment influence are revealed by FES. [ABSTRACT FROM AUTHOR]

Here, we report on core–clad bioactive borosilicate fibers, that we have prepared both with round and rectangular cross‐section profile. The exposed approach, which relies on the stacking and drawing of glass slabs, demonstrates our ability to develop bioactive‐based glass fibers with tailored cross‐section profiles. Tens‐of‐meters‐long fibers were successfully drawn, although suffering from elevated losses in the case of the rectangular ones. The response of the fibers in simulated body fluid was studied for both geometries. We found that a round cladding can act as protective layer, tempering effects of the corrosion. We also noticed that rectangular fibers are more prone to degradation, the enhanced corrosion beginning from their sharp corners as they accumulated residual tensile stress during drawing. To the best of our knowledge, this is the first report on the effect of residual tensile stresses from surface tension deformations applied to the corrosion of rectangular fibers. As geometry plays a critical role on the biodegradation behavior of the fiberglass, we believe the enclosed results could lead to the design of fiber devices with tailored cross‐section profile in order to tune their rate of degradation on solely based geometrical effects. [ABSTRACT FROM AUTHOR]

Epoxy‐based glass fiber nanocomposites (EGFCs) have good static mechanical properties but lack in impact strength. Addition of thermoplastic fillers to EGFCs enhanced the impact strength but with lowered static properties. To overcome this issue, compatibilized polyethylene (PE) fibers and silanized clay platelets were reinforced in the EGFCs. The unique properties of PE fibers such as good toughness, high strength, resistance to chemicals, and light‐weight made them an ideal choice for this purpose. EGFCs were processed through vacuum‐assisted resin infusion molding (VARIM) technique and resulted in significant improvements in an impact strength. Compatibilization of nanoclay/PE fibers was confirmed using FTIR and SEM‐EDS analysis. Nanoclay morphology in EGFCs was determined using XRD and TEM analysis. Reinforcement of maleic anhydride grafted PE fibers and silanized nanoclay in EGFCs significantly increased the impact strength by160% over the reference EGFC (without nanoclay/PE fibers). FE‐SEM micrographs showed improved interfacial interaction among various constituents of EGFCs resulting in superior mechanical performance. The newly developed EGFCs have myriad applications in various industries, namely, automotive (bumpers, frames for racing bicycles etc.), marine (hulls, decks, etc.), aviation (radome, stabilizers, etc.), and sports (archery bows, vault poles, etc.). Highlights: Multi‐scale filler‐reinforced EGFCs fabricated through VARIM process.Compatibilized reinforcement significantly improved impact strength.Silanization of nanoclay validated with FTIR & morphology with XRD/TEM technique.SEM‐EDS and FTIR confirmed successful compatibilization of PE fibers.SEM showed improved interfacial interaction among various constituents of EGFCs. [ABSTRACT FROM AUTHOR]

The main aim of this work is to comparatively reveal the effect of fibre type, length and content on compressive strength and microstructure of structural geopolymer concrete (GPC) produced under constant mixture and curing parameters in order to address the significant gap in present literature. Firstly, GPCs with different NaOH concentrations (i.e., 6, 9, 12 and 15 M) and activator solution/binder (a/b) ratios (i.e., 0.45 and 0.55) were produced in ambient curing condition, and optimum production parameters were determined based on the preliminary evaluations. Then, glass and polypropylene fibres in 6‐mm length (GS6 and PP6) and polyamide and polypropylene fibres in 12‐mm length (PY12 and PP12) were included in GPCs at ratio of 0.4%, 0.8% and 1.2% (by volume). Compressive strength, apparent porosity, bulk density, ultrasonic pulse velocity (UPV), X‐ray diffraction (XRD) and scanning electron microscope (SEM) analysis of GPC samples were carried out comparatively. The inclusion of GS6 fibre enhanced the compressive strength thanks to fibre surface being covered by geopolymer gel and the strong adhesion between GS fibre and geopolymer matrix. SEM images of fibre reinforced GPC (FRGPC) also confirmed the experimental findings, which were attributed to improvement in compressive strength. Regardless of the fibre type, the maximum compressive value strength was obtained from GPC specimens with 0.4% fibre and then decreased. Higher fibre inclusions led to poor compaction, workability issues and inhomogeneous fibre dispersions. A very good relation (R2 = 0.98) was acquired between UPV and compressive strength values of GPC/FRGPC samples. [ABSTRACT FROM AUTHOR]

Bismuth (Bi)‐doped glasses with broadband near‐infrared (NIR) emission have been drawing increasing interest due to their potential applications in tunable fiber lasers and broadband optical amplifiers. Yet, the implementation of highly efficient and ultra‐broadband Bi NIR emission covering the whole telecommunication window remains a daunting challenge. Here, via a metal reduction strategy to simultaneously create a chemically reductive environment during glass melting and enhance the local network rigidity, a super broadband (FWHM ≈ 600 nm) NIR emission covering the entire telecommunications window with greatly enhanced intensity was achieved in Bi‐doped germanate glasses. More importantly, due to the excellent thermal stability, the super broadband Bi NIR emission can be well retained after the glass was drawn into an optical fiber. Furthermore, the transmission loss of 0.066 dB/cm at 1310 nm and an obvious broadband amplified spontaneous emission spectrum spanning a range of 1000–1600 nm were observed in this fiber. This work can strengthen our comprehension of the complicated Bi NIR luminescence behaviors and offer a feasible and universal way to fabricate tunable fiber lasers and broadband optical amplifiers based on Bi‐doped multicomponent glasses. [ABSTRACT FROM AUTHOR]

A complete study on the relation between the injection molding parameters and the resulting fiber length, orientation and mechanical properties is presented for highly reinforced long fiber thermoplastic (LFT) polypropylene (PP). It has been found that the longest fibers obtained are the ones processed with the lowest backpressure and the highest screw speed. The backpressure gains importance over screw speed when the amount of glass fiber reinforcement increases, contrary to what was found for less reinforced thermoplastics. The injection speed does not influence the fiber breakage phenomena, while it has great importance in fiber orientation and thus on the tensile strength, especially when the weight fiber average length is below 1000 μm. When this average is over 1000 μm, fibers begin to weave a mesh that thickens the core region and hinds its orientation, reducing the tensile strength but improving impact resistance. [ABSTRACT FROM AUTHOR]

The development of innovative engineered epoxy composites aiming to manufacture cost‐efficient materials with reduced weight and enhanced physical properties remains as a current industrial challenge. In this work we report an original procedure for manufacturing glass‐fiber epoxy reinforced nanocomposites (GFECs) by employing electrospun fiber‐mats as a reinforcing phase. These fibers have been produced from polyacrylonitrile and multiwalled carbon nanotubes solutions. Optimal protocols are designed by combining Taguchi method with the morphological, structural and mechanical properties obtained by scanning electron microscopy, profilometry and tensile tests. It is demonstrated that GFECs fabricated using GF800 glass fiber show an improvement/enhancement of the mechanical properties with a fracture strain up to 500 MPa (around 20% higher than the non‐reinforced epoxy composite counterpart). It is also shown that GFECs fabricated using GF3M glass fiber exhibited a reduction of the roughness up to 56%, which corresponds with a roughness improvement from N8 to N7 following the guidelines provided by the ISO 1302. These results suggest that this type of nanocomposites would be suitable to be used in the aeronautics and automotive industries. [ABSTRACT FROM AUTHOR]

Glass fiber (GF) composites are one of the significant challenges in recycling thermoset materials. After pyrolysis, the glass fibers lack sufficient strength and show poor matrix compatibility. Here we have investigated a series of multifunctional silane and silazane agents for surface modification of recycled glass fibers that provide a combination of hydrophobic properties and residual reactive groups on the surface. This allowed testing of interfacial effects from the surface modification as well as a potential synergistic compatibilization using maleated PP (MAPP). The treated GFs were used to prepare new polypropylene (PP) composites by multiple extrusion steps, resulting in a series of composites where the dispersion efficiency was attributed mainly to the surface chemistry and compatibilization effects. The amino‐silane modifications of the recycled fibers resulted in further improvements in the mechanical properties of the PP composites in comparison with the hydrophobized GFs. Moreover, synergistic effects from the addition of MAPP were observed with scanning electron microscopy. The results clearly demonstrate that the surface modifications were effective and good alternatives to currently used methods. [ABSTRACT FROM AUTHOR]

Seventy eight dog‐bone shaped ultra‐high performance concrete (UHPC) tensile specimens were designed to study the effects of single steel fiber and hybrid steel fiber with polyolefin (PP) fiber, polyvinyl alcohol (PVA) fiber, glass fiber (GF), polyester (PET) fiber, and basalt fiber (BF) on the compressive strength, tensile strength, peak strain, and fracture energy of UHPC. The results showed that hybrid fiber reinforced UHPC had good toughness damage characteristics, which reflected the strengthening and toughening effects of different fibers. The tensile stress–strain curves of hybrid fiber reinforced UHPC could be divided into the rising section and softening section, and the softening section was significantly influenced by the type and volume content of fibers. Among the microfiber (PVA fiber, GF, and BF), GF had the most significant strengthening effect, PVA fiber had the best ability to improve the deformation of UHPC, and BF had the most significant effect on the improvement of fracture energy. Among macrofiber (PP fiber, PET fiber), PP fiber had a better ability to improve UHPC deformation than PET fiber, but both were lower than microfiber. When the total volume content of steel fiber and PVA fiber was 2.5%, the best toughening and crack resistance effect was achieved when the volume content of steel fiber was 1.5% and the volume content of PVA fiber was 1.0%. Combined with the experimental results, the UHPC tensile σ–ω curves of single steel fibers, hybrid steel–PVA fibers, and hybrid steel–PVA–PET fibers were established, and the predicted curves were in good agreement with the experimental curves. [ABSTRACT FROM AUTHOR]

Fiber‐metal laminates (FMLs) are attracting much attention from researchers as emerging aerospace materials. In this paper, 1060‐H112 aluminum alloy‐carbon/glass fiber laminates were prepared by vacuum bagging method. Subsequently, based on tensile, three‐point bending and low‐velocity impact experiments, the quasi‐static mechanical properties as well as the dynamic response to impact of the two fiber laminates were investigated. The results show that the carbon fiber metal laminate (CARALL) has stronger tensile strength and inter‐ply tensile consistency, while the glass fiber metal laminate (GLARE) has better bending resistance. The impact response of CARALL and GLARE is closely related to the impactor shape and impact energy. The peak loads of the FMLs increased with increasing impact energy over the range of impact energies tested. However, the peak load of CARALL is more sensitive to the impact energy, while the deformation of GLARE is more sensitive to the impact energy. With complete penetration of the impactor into the target, the fibers of GLARE were ductile fracture and fibers of CARALL were brittle fracture for the blunt impactor impact, while the fibers of both GLARE and CARALL were ductile fracture for the hemispherical impactor impact. Under the impact of both impactors, two types of FMLs showed matrix broken, delamination, and local debonding. [ABSTRACT FROM AUTHOR]

In the current study, the effect of adding the encapsulated healing agent with neat polymeric and nanocomposite shells on the mechanical‐healing features of glass fibers/epoxy composite under various loads was investigated. Therefore, the microcapsules with urea‐formaldehyde (UF) nanocomposite shell containing the various weight fraction of silica nanoparticles (0, 1, 2, 3) were synthesized. After that, the flexural, tensile, and interlaminar shear strength (ILSS) samples were destructed by using the quasi‐static penetration method with the damaging force of 500, 1050, and 2900 N, respectively. The maximum healing efficiency in the flexural loads belonged to the composite with the 3 wt% nanosilica on the surface of microcapsules, which was 83.9%. Also, it was found the increment in the weight fraction of silica nanoparticles had a negligible effect on the healing ability of composite under tensile loading. Achieving 135.8% healing efficiency in the composite with the 2 wt% nanosilica under the shear loads can be one of the most important findings in this work. [ABSTRACT FROM AUTHOR]

The rare‐earth (RE)‐doped yttrium aluminosilicate (YAS) glass fibers have demonstrated their unique advantages in single‐frequency lasers due to their high solubility of RE ions and high gain per unit length. However, the RE‐doped YAS fiber is usually fabricated by RE:YAG crystal or ceramic rods and melting‐in‐tube method, which depend heavily on RE:YAG crystal or ceramic rods and, thus, cannot adjust the fiber compositions effectively; there is little research on the multiple RE ions co‐doped YAS fiber deriving from RE:YAG crystal or ceramic rods. In present work, we developed a novel method to fabricate Er/Yb co‐doped YAS fibers efficiently. The Er:YAG and Yb:YAG nanopowders were fabricated by the coprecipitation method, and then the nanopowders were dispersed into liquid organic resin to form a novel UV‐curable nanocomposite, after curing, debinding, purifying, and drawing process, an Er/Yb co‐doped YAS fibers was fabricated, the absorption coefficients of the fiber was measured to be 17 dB/cm at 976 nm (2F7/2 ground level to 2F5/2 level of Yb and 4I15/2 ground level to 4I11/2 level of Er) and 3.2 dB/cm at 1530 nm (4I15/2 ground level to the high states of 4I13/2 of Er). A 1.5‐µm single‐frequency laser was constructed with the 2‐cm Er/Yb co‐doped YAS fiber. The longitudinal mode spacing was calculated to be 2.2 GHz with an effective cavity length of 4.5 cm, and the spectral signal‐to‐noise ratio was higher than 60 dB. To the best of our knowledge, it is the first time that Er/Yb co‐doped YAS fibers are fabricated using the UV‐curable nanocomposites. It indicates that this proposed technology is critical for the fabrication of various types of RE ions co‐doped YAS fibers and their applications in single‐frequency fiber lasers. [ABSTRACT FROM AUTHOR]

In recent years, glass‐fiber‐reinforced plastic (GFRP) applications have expanded. This study elucidates the fatigue fracture mechanism of GFRP with different fiber orientations and experimentally clarifies the relationship between fiber orientation and fracture mechanism by using specimens with unidirectional simple fiber orientations. First, Static tensile and fatigue tests are performed on two types of specimens with fibers oriented in a single direction (parallel to the load axis and orthogonal to the load axis), and it is found that specimens with a single fiber orientation parallel to the load axis shows higher strength in both tests. Next, In the case of GFRP with fibers oriented parallel to the load axis, it is found that fatigue loading causes fatigue crack initiation at the fiber ends, followed by fiber localized debonding due to crack propagation at the fiber‐matrix interface and that the crack propagation rate gradually decreases and stops. Therefore, this suggests that the increase in fiber length of fibers oriented parallel to the load axis in GFRP leads to an increase in the crack propagation life at the fiber‐matrix interface, which leads to an increase in fatigue life. [ABSTRACT FROM AUTHOR]

Design and process‐induced defects in fiber‐reinforced polymers (FRPs) lead to fracture nucleation due to the stress concentrations. In addition to the degradation in mechanical properties, defects can accelerate aging of FRPs and limit their service life. Efforts to understand the impact of defects have largely focused on the mechanical performance of FRPs. However, their impact on aging performance has not yet been extensively investigated. Here, we report the effect of the meso‐scale (missing yarn) and micro‐scale (micro‐crack) defects on the hygrothermal aging behavior of FRPs. Missing yarn defects were generated by pulling‐out yarns in warp and weft directions of glass fabric. Then, micro‐cracks were induced in composite laminates by acoustic emission controlled tensile loading/unloading. After exposing samples to the hygrothermal aging, we found that meso‐scale defects deteriorate mechanical/thermomechanical performance, reaching 30% decrease in the flexural strength. Notably, even though increasing micro‐crack density reduces the moisture saturation time, the aging time is reported as a more predominant design parameter, deteriorating the mechanical performance for micro‐crack‐induced FRPs. [ABSTRACT FROM AUTHOR]

For enhancing impact characteristics, woven glass fiber epoxy laminates are reinforced with short fibers. The 6‐mm‐long slender fillers, when added up to 4% in the matrix, exhibit no influence on the flexural modulus, but at 2% they maximize the laminate's flexural strength. While the dissipation energy continues to increase up to 30 J of impact, the laminates' post‐impact load bearing capacity gets significantly affected beyond 20 J. The reinforced laminates exhibit better elastic response and enhanced damage resistance with as high as 50% reduction in the visible damage area as well as up to 35% increase in the damage initiation force. The degree of damage shows excellent correlation with the visible damage area. The distinct through thickness conical region, diverging from the impact site, is attributed to the presence of microcracks oriented along the fiber directions. The cone boundary, from where the interlaminar failure initiates, is largely the manifestation of transverse matrix cracks. While the damage cone with greater divergence indicates reduced impact resistance of the laminate, the orientation of transverse matrix cracks remains unaffected by the impact energy or the filler content. At low impact energies, the failure initiated from the fiber/matrix interfaces, coalesce to form the matrix cracks, which act as a precursor to the interlaminar failure. However, at high energy levels, several failure mechanisms simultaneously develop with no clear indication of the order of damage evolution. The short fibers enhance the laminate's impact resistance either by arresting the cracks or by developing tortuous crack path with high energy dissipation. [ABSTRACT FROM AUTHOR]

This study investigates the influence of reduced graphene oxide (rGO) coated glass fabrics on the strain sensing and the mechanical characteristics of fiber‐reinforced composites. Graphene oxide was applied in two thicknesses (threefold and fivefold coatings) onto a fabric using a padder mangle machine followed by thermal reduction and infused with an epoxy to manufacture rGO‐enhanced composite. The tensile modulus and flexural strength of the rGO‐enhanced composites with threefold coating were improved by 27% and 6.2%, respectively, compared with the equivalent composite manufactured without rGO. The normalized resistance (ΔR/R0) of composites increased by 0.89% and 3.48% under a cyclic tensile force of 1000 and 4000 N. The magnitude of ΔR/R0 was stable within 30 cycles suggesting a consistent strain sensing performance with a gauge factor of 15.55. The electrical response of the rGO‐enhanced composite was evaluated using a new industrial standard for sensors, by assessing calibration curves. The composite showed low hysteresis and low electrical viscosity which make these materials suitable for industrial piezoresistive strain sensors. [ABSTRACT FROM AUTHOR]

Due to environmental issues and high cost of synthetic fibers, natural or cellulosic fibers have emerged as a promising reinforcement for polymer composites. The hybridization of natural fiber with synthetic fiber is a useful technique to improve the mechanical properties instead of using the natural fibers alone. This research aims to evaluate the influence of glass fiber hybridization on the mechanical properties of continuous, unidirectional, alkali (NaOH)‐treated kenaf‐epoxy composites. At first, the effect of treatment of various concentrations (3, 5, 7, and 9% w/v) of NaOH on the structure of single kenaf fiber was characterized using XRD, SEM, FTIR, and tensile testing. At the optimum 5% alkali concentration the tensile strength, modulus, and %elongation of the kenaf fibers were enhanced by 81%, 114%, and 42%, respectively. The effect of hybridization of 5% NaOH treated kenaf along with glass fiber on the improvement in tensile, flexural, and impact properties for hand laid kenaf‐glass‐epoxy hybrid composite laminates was established. The overall matrix to fiber weight ratio of five different layup sequence laminates was maintained constant at 70:30. It can be concluded from the obtained results that the 15% glass and 15% kenaf fiber hybridized composites exhibited the maximum increment in tensile strength and modulus (68.5% and 19.5%, respectively) in comparison to the unhybridized composites. Further, the flexural strength and modulus were also improved by 21% and 67%, respectively, and the impact strength by 153%. The SEM fractography proved that alkali treatment of fibers improved the fiber‐matrix interfacial bonding whereas fiber breakage, fiber pull‐out and debonding were established as the main fracture mechanisms of hybrid composites. The findings of the present investigation on kenaf‐glass hybrid composites corroborate that they are suitable for secondary structural applications in construction and automobile sectors. [ABSTRACT FROM AUTHOR]

In this study, an effective microscale method based on the parametric modeling scheme of the finite volume method is improved to evaluate the effective thermal conductivity and localized thermal fields of the fiber‐reinforced composites. By comparing with the finite element method and experimental data, it is indicated that the proposed microscale method exhibits a high accuracy in solving their effective properties. On this basis, the mesh sensitivity and fiber volume fraction influence on the thermal conductivity are both investigated. The number of 36 × 36 sub‐cells is employed as the RVE model to balance the computational efficiency and simulating accuracy. In addition, affected by the thermal conductivity and microstructure of constituent materials, the heat flux distribution near the interface between phenolic resin matrix and glass fiber is relatively uniform. The study on the influencing factors of the volume fraction shows that the equivalent thermal conductivity increases slowly at the low volume fraction, while the growth rate of the equivalent thermal conductivity increases significantly at the high‐volume fraction. [ABSTRACT FROM AUTHOR]

In the present study, an attempt is made to replace the synthetic glass fiber used in the FRP structures in terms of natural flax fibers without much sacrifice on static and dynamic stability of the structure. Three types of glass/flax hybrid composite laminates were prepared with different fiber volume fraction of glass and flax fibers. For better understanding purpose, a dedicated glass and dedicated flax laminates were also fabricated. All the laminates were fabricated by vacuum bag molding method with uniform laminate thickness. The mechanical properties of the fabricated laminates, such as tensile strength and flexural strength, were evaluated in accordance with ASTM standards. The impulse excitation technique was used to assess the free vibration characteristics of glass/flax laminates such as modal frequency and material damping. Based on experimentally evaluated mechanical and vibration characteristics a suitable fiber volume fraction for the preferred laminate thickness was suggested to achieve optimum static and dynamic stability. [ABSTRACT FROM AUTHOR]

High‐performance fibers such as carbon, aramid, and glass fiber generally have excellent mechanical, thermal, and chemical resistance and they have potential applications in oil and gas exploitation where high‐temperature and high‐pressure (HTHP) H2S/CO2 corrosive environments usually exist. To investigate the corrosion behavior of these fibers under such environments, two corrosion environments (HTHP water, HTHP H2S/CO2) were simulated in a high‐temperature high‐pressure reactor. Scanning electron microscope, X‐ray diffraction, density measurements, and single fiber tensile test were performed to study the surface morphology, crystal structure, and mechanical properties before and after corrosion. After exposure to the second corrosion environment, the carbon aramid fibers had no obvious mass loss and tensile strength retention of 70.28% and 49.66%, respectively. The surface of the aramid fiber and carbon fibers was significantly damaged which led to an increase in surface defects and a decrease in crystallinity. The glass fiber had clear weight loss due to a large number of defects being formed in the structure and the retention of tensile fracture strength was 48.18%. Corrosion under HTHP H2S/CO2 conditions caused more serious damage to the high‐performance fiber structures. [ABSTRACT FROM AUTHOR]

Nowadays, reinforcement of fiber is necessary for concrete to enhance its quality with mechanical characteristics. The main objective of this work is to determine the mechanical properties of bamboo and glass fiber reinforced concrete. In concrete, E‐glass and bamboo fibers are mixed with three different proportions such as 25:75, 50:50, and 75:25. Cubical‐, beam‐, and cylindrical‐shaped concrete structures are developed for mechanical testing. After the curing period, the cubical structures are utilized for compressive strength testing, the cylindrical specimen for split tensile testing, and the beam‐shaped specimen for flexural strength testing. From the outcomes, 1% fiber substance (glass and bamboo fiber proportions of 75:25) provides better split tensile strength 4.13 N/mm2, compressive strength 42.08 N/mm2, and flexural strength 7.7 N/mm2. The comparative analysis of the proposed concrete composition with the conventional concrete mixture is also carried out. The experimental results are validated using support vector regression, and such predicted outcomes are closer to the experimented values. Furthermore, the ETABS platform is utilized for validating the proposed hybrid fiber reinforced concrete (HFRC) with single reinforcement‐like glass particles. In which, the testing properties like bending moment, shear force, and axial force are favorable for the HFRC. [ABSTRACT FROM AUTHOR]

In this study, a comparative analysis of basalt, E‐glass and hybrid fiber reinforced vinyl ester composites was carried out. Composites were fabricated using vacuum infusion process with 0°/90° and ±45° as fiber orientation angles. The influence of volume fraction on mechanical behaviors and surface morphology of impact fractured composites were analyzed. The glass and basalt fibers oriented at 0° have shown higher load bearing capability, whereas the fibers oriented at 45° angle have shown higher plastic deformation. Hybridized composite having silane treated glass fibers has shown enhanced mechanical properties including tensile strength, bending strength, toughness, and elongation at break due to good bonding between fibers and polymer matrix. The tough and flexible interface between fiber and matrix dissipates more energy through stress transfer from matrix to fiber, allowing increased resistance to shearing. The impact test of BGS‐0.2 hybrid composite showed 103% and 108% of strength improvement compared to basalt (B‐0) and glass fiber (G‐0) reinforced laminates, respectively. However, the fiber orientation at 45 degree showed reduced the strength and modulus with high elongation. The fractography micrographs of hybrid composites have shown the effectiveness of basalt and glass fiber orientation in the composites and bonding between fiber and matrix indicating flexible interphase between the fiber and matrix during impact loading. The composites added with silane have shown marginal increase in water uptake due to presence of polar functional groups in the coupling agent. [ABSTRACT FROM AUTHOR]

The viability of using cellulosic Cymbopogon flexuosus root (CFR) fiber waste from the industry as a reinforcing material in a polyester‐reinforced composite was investigated. Initially, CFR anatomy, mechanical, thermal, physio‐chemical, morphological, and spectroscopy behaviors were investigated. Spectroscopy and chemical analysis were evidence for the richness of cellulose content (74.33%) in the fiber which reflected in increased tensile strength of 315.22 ± 61.72 MPa and thermal stability 272.31°C. Fiber reinforcement was varied from 0 to 50 wt% at random orientation and mechanical, and water absorption properties were correlated with the glass fiber reinforced composite of the same weight percentage. The composite with a 40% fiber combination has an enhancement in mechanical, morphological, and thermal characterization. This comprehensive study confirms the usage of this bio‐material in replacing harmful synthetic material in structural, marine and mechanical industrial applications. [ABSTRACT FROM AUTHOR]

Utilizing recycled or short fibers for making useful engineering composite component is a present research trend and requirement. Current research work explicates the effect of short carbon fibers (SCF) used as secondary reinforcement in woven glass/epoxy hybrid composites and evaluates their mechanical properties. Different concentrations (0.1, 0.3, and 0.5 wt%) of SCF were incorporated to assess the tensile, flexural, and interlaminar fracture toughness (Mode I and II) of the resulted composites. Composites with 0.1 wt% SCF showed 29.02% and 16.08% increment in the tensile and flexural strength, respectively. For Mode I and Mode II interlaminar fracture toughness tests, 0.1 wt% SCF‐GE samples showed the highest strain energy release rate. Double cantilever beam specimens were used for Mode I testing and an improvement of 13.49% in GIC value was observed. End‐notched flexure method was used for the Mode II tests, and 0.1 wt% SCF‐GE samples showed 20.45% increase in GIIC values. This paper explains the various reasons and mechanisms for obtaining such results. Scanning electron microscopy of the fractured surfaces was carried out to perceive the diverse failure micro‐mechanisms that could have been involved. [ABSTRACT FROM AUTHOR]

This research developed epoxy‐based glass fiber reinforced composite (GFRPs) containing multi‐scale fiber reinforcement comprising of silanized nanoclay (nano‐reinforcement) and compatibilized para‐aramid (PA) fibers (micro‐reinforcement) for enhanced impact strength and tensile‐flexural properties. VARIM technique was used for fabrication of GFRPs. Surface modification (silanization) of nanoclay was confirmed by FTIR and that of PA fibers was confirmed by SEM‐EDS and FTIR. Dispersion/morphology of nanoclay in the processed nanocomposites was determined by XRD and TEM analysis. Three different methods were used for the compatibilization of PA fibers. All methods exhibited a substantial increase in impact strength without a decrease in flexural/tensile strength. Nanocomposite containing 1.0 phr MAH treated PA fibers and 2 phr silanized nanoclay showed the highest improvement in impact strength (34% higher than the reference composite) along with minor improvements in tensile strength (6%), and flexural modulus (13%). SEM micrographs of the fractured surface of impact test samples were used to identify the mechanisms/reasons for the improved mechanical performance of the newly developed GFRPs. [ABSTRACT FROM AUTHOR]

The thermomechanical properties of short glass fiber (GF) reinforced polypropylene random copolymer (PPR) composites are investigated. Four composites with different fiber content, namely 10, 15, 20, and 30 wt%, are prepared using melting mixing. For fibers up to 15 wt% the composites exhibit enhanced thermal stability as compared to the random polypropylene. The use of fibers also improve the mechanical strength of the matrix. In particular, PPR/GF30% demonstrates the highest Young modulus, yield strength, and storage modulus values, while PPR/GF10% has the best ductility among the composites. Incorporation of 10 wt% fibers also increases the yield strength and storage modulus of the PPR matrix by approximately 1.6 and 1.2 (for temperatures higher than 60°C) times, respectively. These results suggest that GF reinforced PPR is a composite suitable for advanced technological applications. [ABSTRACT FROM AUTHOR]

Continuous glass fiber reinforced polylactic acid (CGF/PLA) composites were prepared by 3D printing technology in this study. The multi‐roll melt impregnation mold was manufactured according to the melt impregnation model. CGF/PLA filament was prepared by a melt impregnation device, and then used to prepare CGF/PLA composite materials by the self‐modified 3D printer device. The full impregnation of the fibers was achieved by the action of the coverage angle of the tension roller in the impregnation mold. The effects of the total coverage angle, traction speed, fiber content, and impregnation temperature on the fiber impregnation effect and 3D printed product performance were studied. The bending strength, tensile strength, impact strength, and interlayer shear strength of the printed sample reached 312, 220, 154, and 14 MPa, respectively. The strategy in this study can effectively improve the impregnation effect of PLA resin on CGFs and promote the development and application of 3D printing technology in the field of high‐performance composite manufacturing. [ABSTRACT FROM AUTHOR]

Further attenuation of Rayleigh scattering of silica glass is required to extend the capacity of long‐distance optical fiber communication. To theoretically examine the effect of aluminum and fluorine co‐doping on the density fluctuations of silica glass, which is related to Rayleigh scattering, a set of force‐matching potentials (FMP) for simulating F‐doped aluminosilicates was developed using Bayesian optimization based on density functional theory calculations. Molecular dynamics (MD) simulations with the new FMP could evaluate the densities of silica glasses to which a small amount of fluorine was doped and those of aluminosilicate glasses with a wide range of aluminum contents within reasonable accuracy. The FMP successfully represents the changing role of aluminum from a network former without a compensating cation (threefold coordination) to that with a compensating cation and a charge compensator in the aluminosilicates. Indeed, relative concentrations of four, five, and sixfold‐coordinated aluminum observed by NMR measurements were reproduced better than the original Teter potential at a high aluminum content. At an aluminum content lower than 1 mol%, threefold‐coordinated aluminum was observed, which is consistent with ESR measurements. After careful validations of the FMP, the effect of the co‐doping of alumina and fluorine on the density fluctuations of silica glass was computationally examined. Consequently, it was expected that the co‐doping might not sufficiently attenuate the Rayleigh scattering, even though 1 wt% fluorine would be able to reduce the density fluctuations of aluminosilicate glasses for some extent. This is because more alumina‐doping increases density fluctuations of silica glass if the drawing temperature and procedure are the same with those for silica glass fiber. Thereby, a possible fabrication process to sufficiently attenuate the Rayleigh scattering of the F‐doped aluminosilicate glass was proposed, according to the density fluctuation analysis at high temperature. [ABSTRACT FROM AUTHOR]

The increasing demand for lightweight and economical automotive components boosts investigation of advanced materials and new lightweighting technologies. This work employs the novel microcellular injection molding technology Ku-Fizz™. The process introduces gas with granulates at moderate low pressures into the feed zone of the injection molding machine. Ku-Fizz is controlled by gas pressure; thus, a simple plate geometry was molded and the effect of various gas contents on the microstructure was analyzed. The material used was a chemically coupled glass fiber-reinforced polypropylene compound. Optical microscopy was employed to measure the foam microstructure. Microcomputed tomography was used to quantify the fiber volume fraction and the orientation tensors. Results of the fully characterized microstructure showed cell density increasing and cell size decreasing with gas pressure and melt flow direction. Fiber length increased with gas content. Cell growth displaced fibers from the center of the part towards the mold surface, changing the fiber concentration and global fiber orientation. [ABSTRACT FROM AUTHOR]

In this paper, we present a new series of alkali‐free bioactive glasses (BG) based on FastOs® composition (38.49 SiO2 – 36.07 CaO – 19.24 MgO – 5.61 P2O5 – 0.59 CaF2, expressed in mol %), which was modified by partially replacing silicon dioxide network‐former with boron trioxide network‐former, utilizing calcium oxide as a charge compensator. The main objective of this study was to obtain a new family of bioactive glasses suitable for the fabrication of glass fibers. The BGs were prepared by melt quenching technique and their structural and thermal properties were determined. Glass rods were used to obtain fibers by the classic drawing technique. The bioactivity of the fibers was subsequently assessed through immersion tests in simulated body fluid (SBF) to establish their ability to form hydroxyl carbonated (HCA) apatite onto their surfaces. Glasses with moderate substitution of SiO2 with B2O3 exhibited enhanced thermal properties, allowing to significantly suppress the crystallization trend, and favoring to draw the fibers. The structure of the studied glasses was obtained by NMR spectroscopy. The structure‐property correlations were established by their relationship to the configurational entropy. Smaller amounts of substitution resulted in larger entropy of the glasses. Moreover the SBF tests revealed an extensive formation of HCA, comparable to the parent FastOs®BG composition, which assures fast bonding to the bone. Thus, presented glass fibers may be considered as promising materials for wool‐like bone implants or as reinforcing constituent of biopolymer matrix composites. [ABSTRACT FROM AUTHOR]

The stress interaction failure criterion was applied to three compression‐molded sheet molding compound (SMC) materials. Two are epoxy‐based compounds with randomly oriented carbon fiber tows, and the third material consists of glass fiber bundles randomly oriented in a vinyl ester resin. The failure surface was built using tensile test results at different orientations with respect to the flow direction, resulting in combined loads in the principal stress coordinate system. Three unknown variables arise from using only tensile strength values. Solving a system of three equations derived from the criterion function and using the failure values obtained from destructively testing at three different orientations, the unknown variables as well as the interaction strength components were determined. Results show good agreement for all three materials. Overprediction was found in some instances, attributed to the effect of fiber orientation distribution in the part, and to the complex interactions of the filled structures. To allow a more direct comparison between predicted and experimental data, the resulting failure surface was translated to the global coordinate system (σxx) and compared to the data derived from destructive tensile tests. Good agreement for all materials was observed, with underprediction noted for some orientations, attributed in part to the equation solving method and the nature of the mesostructures of the composites, where interactions between the tows, resin, mold walls, and fibers are present. The results of this work show that the methodology described permits the development of a failure surface for SMC materials when limited data is available. [ABSTRACT FROM AUTHOR]

Various approaches to reduce the weight of electronics and automobile devices have been explored. For instance, an alternative polymer was utilized to replace metals. In the present study, a new circular braided glass fiber/epoxy composite (braid angle: 45°, fiber: 48 vol%) with a helical structure was fabricated as a model coil spring for weight reduction. A plaster‐sacrificial compression mold was especially designed to fabricate helical composites without voids. The spring design was validated by the experimental results of torsional tests. Plastic deformations of the epoxy resin were measured using creep tests to eliminate high‐temperature plastic deformation (HTPD) of the composites. Pre‐strain applied thermal aging was utilized to remove HTPD. Mechanical properties of the composites were also investigated. The mechanism of mechanical failure was found to be the interfacial failure. For preparation of uncured prepreg, resin permeability was measured to a range of 10−10 m2. Resin transfer in the glass fiber‐braided textiles occurred due to the combination of viscous and diffusional flow mechanisms. Based on the results in this study, the facilely designed coil spring composite can be used for various applications, especially automotive parts. [ABSTRACT FROM AUTHOR]

A change in the length distribution of glass fiber was induced by mixing long glass fiber 30%‐ reinforced polypropylene composites with recycled composites of short glass fiber 30%‐reinforced polypropylene, and the improvement in mechanical properties was investigated. Changes in mechanical properties were confirmed as a function of the number of recycles and mixing ratio of the composites, and the average fiber length and length distribution of the glass fibers were analyzed using a three‐dimensional measuring machine. The tensile strength, flexural strength, flexural modulus, and impact strength of the blend of a once‐recycled composite of short glass fiber‐reinforced polypropylene and once‐recycled composite of long glass fiber‐reinforced polypropylene in a ratio of 40:60 were 99%, 102%, 100%, and 100% those of a virgin composite of short glass fiber‐reinforced polypropylene, respectively. In addition, the average length of the glass fiber of this blend was 0.305 mm, which was similar to that of the virgin composite of short glass fiber‐reinforced polypropylene (0.313 mm); furthermore, the distribution ratio of long fibers of length 1 mm or more was 5%. The length distribution of the glass fibers was significantly altered by the combination of the recycled composites and the long glass fiber‐reinforced composite; accordingly, the deteriorated mechanical properties of the recycled composites could be significantly recovered. [ABSTRACT FROM AUTHOR]

In this work, barium sulfate (BS) fibers with a three‐level nanorod‐assembled hierarchical structure have been synthesized in a large scale by the barium oleate precursor hydrothermal method. A new kind of anti‐acid and anti‐alkali fire‐resistant BS inorganic paper has been developed using BS fibers, glass fibers and inorganic adhesive, and it has advantages such as high flexibility, good tensile strength, excellent fire‐resistant properties, excellent corrosion resistance to strong acids and strong alkalis. It is expected that the anti‐acid anti‐alkali fire‐resistant BS paper has promising applications under various high‐temperature and harsh conditions. [ABSTRACT FROM AUTHOR]

Nowadays, glass fiber (GF) reinforced polyamide 66 (PA66) composites have attracted strong interests in commercial and engineering applications due to many advantages, such as corrosion resistance, high potential of integration, self‐lubricating, and high toughness. However, it is very difficult for traditional plastic molding equipment to concurrently obtain the increase of fiber retention length and the improvement of fiber dispersion during the PA66/GF composites manufacturing, which greatly limit the widespread application of such composites. An innovative twin eccentric rotor volume pulsating plasticizing transportation equipment (TERE) based on series explosion effects, is applied to prepare PA66/GF composites at different rotor speeds and fiber loadings. Inside the PA66/GF30 composite prepared by TERE, the fibers are evenly dispersed in polymer matrix and the average fiber length increases by 3.2 times when compared to that of twin‐screw plasticizing transportation equipment (TSE). The Charpy impact strength of PA66/GF composites prepared by TERE is nearly twice that of TSE at all fiber contents. The fatigue properties, thermal oxygen aging properties, and creep properties of the TERE composites exhibit better effects than the TSE composites, indicating that the TERE can ensure longer fiber length and better dispersion effect simultaneously. [ABSTRACT FROM AUTHOR]

This article presents the experimental findings of tension‐tension stress‐controlled fatigue tests performed on low‐density sheet molding compound (LD‐SMC). LD‐SMC composite is a type of SMC including a polyester resin reinforced with chopped glass fibers bundles and hollow glass spheres. The coupled frequency‐amplitude affects the nature of the overall fatigue response, which can be controlled by the damage mechanisms accumulation and/or by the self‐heating. In fact, the self‐heating produced a material softening and decreased the fatigue lifetime. For fatigue loading at 80 Hz, self‐heating has been observed and yielded to a temperature rise to 65°C, which is more than a glass transition temperature of polyester. Thus, the polyester matrix is subjected to remarkable thermally activated modifications of its physical state. Multiscale damage analysis of the randomly‐oriented sample in fatigue showed that the first observed damage phenomenon corresponds to the debonding of the hollow glass microspheres occurring in the fiber depleted zones. [ABSTRACT FROM AUTHOR]

Light weighting has become an integral part of vehicle design. This strategy makes use of fiber‐reinforced thermoplastics, which can be injection molded into complex shapes. Composite design work requires knowledge of the orientation state throughout a part to predict properties like stiffness and strength. Although evolution models for the orientation state have been developed, each requires empirical parameters, and no standard method for obtaining these exists. This work continues efforts to find such a test, particularly for long (average length > 1 mm) glass fiber composites. Here, a polypropylene loaded with 30, 40, and, 50 wt% long glass fiber is subjected to startup of shear and nonlubricated squeeze flow (NLSF). The orientation evolution was reported for both flows and an attempt was made at fitting several orientation models to the data. The measured orientation evolution from startup of shear was slower than expected, and this slower evolution appears to result from the combination of the initial orientation state and fiber concentration. On the other hand, the measured orientation profile from NLSF was found to be essentially independent of fiber concentration. However, the NLSF orientation profile could not be replicated with a single set of parameters. Rather, shear‐like parameters made reasonable predictions in shear‐dominated regions, and extension‐like parameters made reasonable predictions in extension‐dominated areas, in concordance with results from short glass fiber composites. [ABSTRACT FROM AUTHOR]

To investigate the possible structural differences between silica glass fibers and bulk silica glasses, electron energy loss spectroscopy (EELS) has been used to study the short‐range and medium‐range structures of both forms of silica glasses. The short‐range structure of silica glass, such as the coordination and symmetry, was investigated by the energy loss near edge structure (ELNES) of Si L2,3‐edges. The ordering structure in the medium‐range was analyzed by the exponential optical absorption edge also known as the Urbach edge of the glasses. The optical absorption data were obtained from the low energy loss spectrum of EELS through Kramers‐Kronig analysis. The results show that silica fiber has the same short‐range structure as the bulk specimen, but is significantly more disordered than the bulk glasses. [ABSTRACT FROM AUTHOR]

The study investigates the thermo‐mechanical properties of isotactic polypropylene (iPP) hybrid composites in reference to various amounts of particle‐ and fiber‐shaped inorganic fillers. Three grades of hybrid composites were prepared as a function of filler amount: 5, 10, and 20 wt% and different ratios of glass fiber (GF) and calcium carbonate (CaCO3). The main objective is to describe the relationship between the hybridization efficiency and mechanical performance of polypropylene‐based composites. The analysis of the thermo‐mechanical properties of the composites shows that both the total amount of the filler and the ratio of GF and CaCO3 clearly influence the properties of the composites. Hybrid composites with the highest amount of the GF display improved thermo‐mechanical stability. The presence of well‐dispersed CaCO3 in the composites was found to improve elongation at break and Vicat softening temperature values. Even though it is glass fiber, which shows higher filler effectiveness and visibly reinforces the composite samples, causing an increase in tensile strength or reinforcing efficiency, replacing up to 50% of this filler with calcium carbonate does not result in a considerable deterioration of the properties of the material. [ABSTRACT FROM AUTHOR]

The usage of thermoplastic elastomers (TPEs) is increasing, and integrated hard‐soft parts can be mass produced by two‐component injection molding (or sequential molding). A key property of such parts, the adhesion between the two materials, is the topic of this study. The hard part (the first molded component) in this study was polyamide‐12 with 0 to 50 wt% glass fibers (PA12‐GF). As the second component, two TPEs were used: a vulcanized TPE and a styrenic TPE, both modified for adhesion to polyamides. The adhesion, assessed by 90° peel tests, increased with increasing melt temperatures and TPE injection rate, while it decreased with increasing glass fiber fraction in the PA12‐GF. Based on characterization of cross‐sections and fiber distributions near the interface, we propose some hypotheses for the effect of fiber fraction on the fusion between PA12‐GF and TPE. These hypotheses involve the near‐surface properties of the PA12‐GF materials, microstructure, thermo‐mechanical properties, and thermal properties. A direct effect of increasing the glass fiber fraction, that is, a reduction in adhesion as more fibers are present at the interface, does not seem to be a major effect, since few fibers are in direct contact with the TPE for any fiber fraction. [ABSTRACT FROM AUTHOR]

The effect of hydrostatic pressure of up to 40 MPa on the seawater permeation, crystalline structure, and mechanical strength of carbon fiber and glass fiber‐reinforced polyoxymethylene (POM) composites was investigated. The experimental results reveal that hydrostatic pressure slightly promotes seawater permeation throughout the POM composites and degrades the bonding strength of the matrix–fiber interface. In the POM matrix, the seawater hydrostatic pressure does not influence the chemical stability but induces a physical chain scission process, which is characterized by linearly decreased molecular weight. The chain scissions initially entangled in the amorphous region are supposed to have sufficient mobility to join the crystalline phase. The increased crystallinity, albeit slight, together with the compress effect of hydrostatic pressure may possibly account for the stable mechanical strengths of the POM composites. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 137, 48686. [ABSTRACT FROM AUTHOR]

The objective of this paper is to research fiber distribution and mechanical behavior (tensile, flexural, and Charpy impact properties) of long fiber reinforced thermoplastic (LFT) plates made by injection molding. The plates were made of long glass fiber reinforced polyamide 6,6 granules and injected using two types of molds, including center‐gated and end‐gated injecting modes, to obtain different fiber orientation state. In addition, end‐gated plate was cut along three directions (0°/45°/90°) to main flow path, in order to experimentally investigate the effects of fiber orientation on mechanical properties. It is found that there is skin‐shell‐transition‐core structure across thickness of plate, resulted from different fiber orientation. Furthermore, end‐gated plate has more obvious fiber orientation at shell and core regions than center‐gated plate. The experimental results demonstrate that fiber orientation has significant effects on modulus, strength, toughness, and full‐field strain evolution. Tensile and flexural properties decrease by over 50%, as the cutting angle with respect to flow direction changes from 0° to 90° in end‐gated plate. Moreover, unnotched and notched strength drops by 66% and 33%, respectively, from 0° to 90° off‐axis angle. These results show apparent mechanical anisotropy of LFT. Shell‐core structure also significantly influences strain distribution and fracture morphology. [ABSTRACT FROM AUTHOR]

Polypropylene (PP) is widely used in the automotive industry due to its excellent mechanical properties, good formability, and low cost. Herein, the spray‐free PP composites reinforced by graphene oxide@short glass fiber (GO@SGF) were fabricated by extrusion compounding and injection molding. Aluminum powder was used as spray‐free filling materials. The microstructure and composition of SGF and GO@SGF are investigated using scanning electron microscopy and X‐ray photoelectron spectrometer. The effect of GO@SGF on the mechanical properties of spray‐free PP composites was studied. The results showed that both tensile strength and modulus were effectively improved by incorporation of GO@SGF. This mainly attributed to the improved interfacial bonding between the reinforcements and matrix. [ABSTRACT FROM AUTHOR]

A novel strategy of multi‐walled carbon nanotubes‐montmorillonite (MWCNTs‐Mt)‐modified glass fiber fabrics (GFf) was used here to reinforce interlaminar regions of epoxy composites. One/two‐dimensional MWCNTs‐Mt hybrids with different mass ratios of MWCNTs and Mt were combined with the GFf, respectively, prior to a resin injection process. Making use of this strategy, uniformly dispersed MWCNTs and highly exfoliated Mt at the fiber/matrix interface could be achieved; meanwhile, mechanical and interfacial properties of resultant composites were greatly enhanced. Under a mass ratio of MWCNTs:Mt (0.2:1), the interlaminar shear, tensile, and flexural strengths of resultant composites were improved by 31.0%, 26.0%, and 21.9%, respectively; the storage modulus increased by 23.6%, compared with the composite without MWCNTs‐Mt. Also, the work of fracture obtained from interlaminar load‐displacement curves and peak loss moduli of resultant composites were significantly enhanced, indicating the synergistic toughening effect of MWCNTs and Mt. [ABSTRACT FROM AUTHOR]

In the present study the effectiveness of two different biodegradable polymers, namely Polylactic acid (PLA) and ECOVIO (EC), a blend of a copolyester and PLA, as matrix materials for basalt fiber composites, prepared with the "film stacking method" has been investigated. Comparison with composites based on glass fiber mat has also been performed. The addition of basalt fibers, leads to a significant improvement in tensile and flexural strength and stiffness. The ECOVIO/basalt fiber composites exhibited the highest percentage enhancement, while the failure strain decreased dramatically. Therefore, the basalt fabrics appear to have a competitive mechanical performance with the glass fiber mats employed. [ABSTRACT FROM AUTHOR]

In this work, environment friendly Ga‐Sb‐S‐I chalcohalide glasses and fibers are developed for mid‐infrared applications. The developed Ga8Sb32S60‐xIx (x = 0‐10) glasses have a transmission window of ~0.7‐14 µm, linear refractive indices (n0) of ~ 2.690‐2.751 at 1.55 µm, nonlinear refractive indices (n2) of ~10.5‐12.4 × 10−14 cm2/W at 1.55 µm, and zero dispersion wavelengths (λ0) of ~4.94‐5.25 µm. The developed Ga8Sb32S55I5/Ga8Sb31S56I5 (core/cladding) fiber can transmit infrared light from below 2 µm to ~8 µm, and shows the minimum loss of ~1.2 dB/m at ~6 µm. The wide transmission window, high optical nonlinearity and superior thermal stability against crystallization of the glasses, and the good 2‐8 µm transmission property of the fiber make these materials promising for mid‐infrared applications such as thermal imaging, nonlinear optics, and laser transmission. [ABSTRACT FROM AUTHOR]