Filled Glass Fiber Research Articles

Effect of atomic oxygen and vacuum thermal aging on graphene and glass fibre reinforced cyanate ester-based shape memory polymer composite for deployable thin wall structures

Deployable components and structures are a crucial part of space exploration. Due to fewer parts, low weight and cost, shape memory polymers (SMPs) and their composites (SMPCs) are considered ideal candidates for this. However, lower thermal stability and poor durability in the space environment have limited their applicability. This research work details the development of Graphene Nanoplatelets (GNP) filled Glass Fibre (GF) reinforced cyanate ester-based SMPC with 0/90° and ±45° sandwich fibre lay-up configuration capable of multidirectional shape programming. The SMP matrix was synthesised by mixing Cyanate Ester and Polyethylene Glycol (PEG) with added GNP. SMPC was fabricated by pouring the SMP mixture into a pre-prepared glass mould with the added GF layers. The synthesised SMPC showed shape programming and recovery at 169.01 ± 0.62 °C and stable thermomechanical properties at the temperature of 130 °C. Durability tests at extreme environmental conditions including Atomic Oxygen exposure, thermal vacuum aging, and elevated-temperature behaviour tests were conducted as these tests evaluate the durability and applicability of the SMPC for use in Earth's orbits and lunar environments. The performances of the samples before and after durability tests were measured through mechanical tests, shape memory effect tests and a series of characterisation methods such as microscopic image analysis, FTIR and dynamic mechanical analysis. According to the results, AO exposure affected the SMPCs by eroding their surface. There were no changes in the chemical structure of the SMPC yet the thermomechanical, mechanical and shape memory properties were decreased without compromising their safe operational levels such as storage onset temperatures (128.79 ± 3.08 °C), maximum tensile stress (114.99 ± 21.52 MPa), shape fixity (100 %) and recovery ratios (100 %). The erosion resistance of the GNP-filled SMPCs was improved with ∼54.35 % less erosion than the SMPC without GNP. The vacuum thermal aging slightly slowed shape recovery from 31.17 % to 8.32 % at 160 °C due to PEG crosslink degradation, however, 100 % shape recovery was achieved at the end. Further durability tests under cryogenic temperatures and effects after vacuum thermal cycles are warranted to observe the synergistic effect on the SMPC for future developments. Exploring the scalability and additive manufacturability of the developed SMPC can be advantageous in the future while mitigating challenges such as complex shape programming, long-term materials degradation, resource efficiency and compliance with safety standards.

Impact of graphite on tribo‐mechanical, structural, and thermal behaviors of polyoxymethylene copolymer/glass fiber hybrid composites via Taguchi optimization

AbstractUnique hybrid thermoplastic composites based on polyoxymethylene copolymer (POM C), 10 wt.% glass fiber (GF) and graphite (Grt) filler at 1, 3, and 5 wt.% were developed using injection molding technique. According to the Taguchi L16 orthogonal array, present experiments were carried out with the aim of determining the coefficient of friction (COF) and specific wear rate (SWR) under a range of loads (namely, 5, 10, 20, and 30 N), sliding speeds (namely, 200, 400, 600, and 800 rpm), and run times (namely, 15, 30, 45, and 60 min) with varying wt.% of Grt (namely, 1, 3, and 5 wt.%) throughout the experiment. Analysis of variance (ANOVA) was used to evaluate the most significant factors that affect the output functions (viz., COF and SWR). The findings demonstrated that POM C/10GF composites' tribo‐mechanical, structural, and thermal properties were considerably improved upon by including Grt. Various microscopical methods were also employed to study the wear mechanisms of the composites and the surface morphology of the worn samples. The POM C/10GF with a 3 wt.% of Grt exhibited superior tribological properties owing to its enhanced interfacial bonding characteristics, resulting to increased wear resistance.Highlights Injection molded POM C/10GF hybrid composites with 1, 3, and 5 wt.% graphite (Grt) Structural, thermal, chemical, tribo‐mechanical and microstructural studies Design of experiment with variable loads, times, speeds, and Grt compositions COF and specific wear resistance as response Optimization of hybrid composite composition using Taguchi L16 orthogonal array

Mechanical and thermal properties of rice husk/glass fiber/polylactic acid composites

AbstractPolylactic acid (PLA) composites reinforced with rice husk and glass fiber can improve the properties in the aera of the material for vehicle application. In this work, the PLA composite was made and its properties were evaluated using scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). SEM observed that the polymer matrix contained a uniform dispersion of 10 wt% rice husks. The tensile strength and bending strength of the composite are 45.8 and 48.2 MPa, respectively, which are 52% and 41% higher than that of the base material PLA. TGA revealed that the thermal stability of the composite deteriorated with increasing rice husk content. The DTG curve indicated that the incorporation of rice husk and glass fiber led to a reduction in the maximum degradation rate of the PLA matrix. As a result, the thermal degradation of the PLA composite exhibited enhanced stability. The average apparent activation energy (Ea) of the composite, determined using the Friedman (FD), Flynn Wall Ozawa (FWO), Starink (ST), and Kissinger (KS) models, falls within the range of 90 to 120 kJ mol−1.Highlights Silane coupling agent was used to improve the interfacial compatibility of fillers. The synergistic action of rice husk and glass fiber fillers enhances the mechanical properties of polylactic acid composites. The mean apparent activation energy (Ea) of the composite was calculated using four models, with values in the range of 90 to 120 kJ mol−1. The Flynn Wall Ozawa and Starink models showed better stability against temperature changes compared to the Friedman model.

Modelling and optimization of fabrication parameters for multi-walled carbon nanotubes-filled GFRP composites using RSM and Rao-1 algorithm

This study presents an optimized approach for fabricating multi-walled carbon nanotubes (MWCNTs) filled glass fibre reinforced polymers (GFRP) composites using hybrid optimization approach. The experimental runs performed as per Box-Behnken design of response surface methodology (RSM) by considering three fabrication parameters: MWCNT loading, sonication time (ST), and oven curing temperature (OCT), and the output response, ultimate tensile strength (UTS) is noted. Analysis of variance (ANOVA) is employed to ascertain the significance of the effects that each factor has on UTS and found fabrication variables, OCT, and combined effects of ST and OCT are most significant. Other variables, direct effects of MWCNT loading, interaction effects of all three combinations have influence on UTS. Mathematical modeling is postulated using RSM from which contour plots are drawn to illustrate both direct and interactive effects and reveal fabrication parameters have detrimental effects on UTS. The mathematical equation of UTS is then solved by Rao-1 optimization algorithm and obtained condition is: 1.0% of MWCNT loading, 97.5 min of sonication time, and 76 °C of oven curing temperature and corresponding UTS of 624 MPa. SEM analysis has also been performed to verify the distribution of MWCNTs in the GFRP and observed uniform dispersion of MWCNTs in the developed composite. A confirmatory test validates the predicted optimal fabrication condition derived from the RSM combined with Rao-1 algorithm, ensuring that the methodology has ability to enhance the UTS of MWCNTs-embedded GFRP composites.

Water Absorption, Thermal, and Mechanical Properties of Bamboo Fiber with Chopped Glass Fiber Filler-Reinforced Polyester Composites

This study explores the investigations of bamboo fiber-reinforced polyester composites with chopped glass fiber (CGF) filler, focusing on addressing the challenges of low mechanical properties, limited thermal stability, and high moisture absorption. The two types of composites were fabricated using the hand layup method, that is, long unidirectional 0° bamboo fiber (BF) and randomly oriented short bamboo fiber (BP) reinforced a polyester matrix with chopped glass fiber (CGF) filler. By incorporating CGF filler, significant improvements in mechanical properties were achieved across both types of bamboo fiber, surpassing the limitations of unfilled composites. Notably, the composite formulation consisting of 40% wt. of unidirectional 0° BF and 5% wt. of CGF filler exhibited superior ultimate tensile strength, flexural strength, impact strength, water absorption, and thermal stability. This composite demonstrated remarkable enhancements, with increases of up to 131.22 MPa, 128.76 MPa, 113.3 kJ/m2, 1.94% water absorption, and up to 255°C (representing a 10% improvement) in thermal stability compared to the unfilled composite. Statistical analysis revealed quadratic models for the mechanical properties of long unidirectional 0° bamboo fiber composites, while water absorption exhibited a linear two-factor interaction model. For randomly oriented short bamboo fiber, the models for tensile, flexural, and water absorption properties were linear, while the impact energy model showed a quadratic relationship. These statistical models provide valuable insights into predicting the properties of bamboo fiber-reinforced polyester composites. This research underscores the significance of bamboo fiber-reinforced polyester composites in wall partition systems. This study paves the way for improved performance in these areas. The findings highlight the potential of incorporating CGF filler, enabling enhanced mechanical strength, increased thermal stability, and improved resistance to moisture-related issues. The derived statistical models offer valuable guidance for predicting the properties of these composites, facilitating their application and adoption in the construction industry.

UAV-Mounted Tank for Processing Agricultural Land with Liquid Agrochemicals

To process agricultural crops, unmanned aerial vehicles carrying tanks with liquid chemicals are used. The paper highlights that containers made of polypropylene and polyethylene exhibit inferior qualities compared to those made of fiberglass, specifically, in terms of strength, thermal stability, resistance to ultraviolet rays, and service life. (Research purpose) To design and manufacture a tank made of composite fiberglass material with a water hammer damper. (Materials and methods) S-glass and epoxy vinyl ester resin were selected for the tank, as they exhibit superior resistance to chemical influences. To construct the tank elements, spray application, impregnation of glass fiber filler in a closed form, and winding were used. (Results and discussion) A comparative analysis was conducted on tank models, assessing their performance with and without a water hammer damper. The effectiveness of the suggested solution has been substantiated through the utilization of KOMPAS-3D software in the KompasFlow application, Within this software, the hydraulic shock is simulated to propagate inside the tank, reflecting off the walls, and gradually diminishing. Load and strength calculations for the fiberglass tank were performed by considering fiberglass parameters using the APM FEM application. (Conclusions) A tank model designed for application of liquid chemical substances in crop spraying from unmanned aerial vehicles has been developed. Innovative methods were employed in the manufacturing of the tank components. Additionally, careful consideration was given to the feasibility of maintenance and reparability. The tank’s volume (experimental sample) measures 0.0158 cubic meters, with a length of 480 millimeters, a width of 216 millimeters, a thickness of 3.6 millimeters, and a weight of approximately 4 kilograms. The design for mounting the composite tank on the unmanned aerial vehicle ensures that the weight of the unmanned aerial vehicle does not impact the tank.

Strain rate dependence of 3D printed continuous fiber reinforced composites

Fused Deposition Modeling (FDM), one of the most popular additive manufacturing technologies in polymer 3D printing, has been increasingly used in fabricating continuous fiber reinforced composites (CFRCs) in recent years. Intensive research has been conducted on the quasi-static mechanical properties of FDM made CFRCs and the corresponding failure mechanisms. However, limited research has been reported on the dynamic mechanical behavior of CFRCs fabricated using FDM. This paper presents a comprehensive experimental study to understand the deformation and load carrying capacity of FDM-fabricated continuous fiber reinforced Onyx (CFRO), with a focus on the dynamic tensile loadings up to strain rate of 100/s. The deformation and failure mechanisms of FDM-fabricated CFROs under dynamic loadings have been identified after microstructural analyses of fractured specimens. The effects of fiber type, fiber volume fraction, and strain rate on the tensile behavior have been revealed for Onyx reinforced by carbon fiber filaments (CFF), glass fiber filaments (GFF), and Kevlar fiber filaments (KFF). Empirical formulas have also been derived to describe the relationships between the elastic modulus, ultimate tensile strength (UTS) and fiber volume fraction. The results demonstrate that increasing the strain rate from 6.7 × 10−4/s to 100/s substantially enhances the UTS of all three types of printed CFRO.

Low-velocity impact failure of foam-filled GFRP trapezoidal corrugated sandwich structures

In this paper, a new lightweight sandwich structure with polyurethane foam filled glass fiber reinforced polymer (GFRP) trapezoidal corrugated sandwich structure is fabricated. Based on the low-velocity impact tests, the impact failure performance and energy absorption efficiency of polyurethane foam filled sandwich structures are investigated. Low-velocity impact tests were carried out on the node and base positions of the foam filled trapezoidal corrugated sandwich structure by using a drop hammer test machine, and the set impact energy range was 25 J – 150 J. Experimental results show that when the impact energy is the same, the maximum impact load and maximum energy absorption generated by the node impact are greater than the base impact, which proves that the node position has better impact resistance and energy absorption effect than the base position. In addition, by comparing the displacement-time curves of foam filled and unfilled sandwich structures, it is found that when the impact energy is the same, the slope of the displacement-time curve of unfilled specimen is greater than that of foam filled specimen. Therefore, within the same time, the deformation of unfilled specimen is larger than foam filled specimen during the impact process, which demonstrates the effectiveness of polyurethane foam filling on the gain of sandwich structure.

The influence of thickness and recycled milled glass fiber fillers on the delamination resistance of polymer composite angle brackets

AbstractComposite structures with L, C, and T shape geometries are commonly used in the design of aerospace structural components. These complex structures are prone to delamination failure at the curved region. This study investigates the effect of thickness and recycled milled glass fiber fillers to improve the strength properties and delamination resistance of glass/epoxy composite angle brackets. Different thicknesses of 3.5 mm (16 layers), 5 mm (24 layers), and 6.5 mm (32 layers) specimens were subjected to four‐point bending test with acoustic emission (AE) monitoring for evaluating damage resistance. Mechanical results reveal that the specimen with a higher thickness of 6.5 mm has better damage tolerance, followed by 3.5 and 5 mm angle brackets. Moreover, the location of AE signals and % of AE hits noticed the initiation and propagation of delamination in 5 mm thickness specimen at the earlier stage of loading. However, the curved beam strength and interlaminar tensile strength (ILTS) of 5 mm thickness specimen were improved by 31.02% and 19.2% respectively, through the incorporation of 2 wt% of fillers. Further, the interfacial adhesion between the fillers and epoxy matrix was studied using Fourier‐transform infrared analysis to confirm the improvement of delamination resistance in 5 mm thickness specimen. Finally, the mechanical and AE results were well correlated with field emission scanning electron microscope images to characterize the damage mechanisms in composite angle brackets.Highlights Effect of thickness on the delamination resistance of composites was studied. Interlaminar properties of composite angle brackets were assessed. Acoustic emission parameters were used to study the damage mechanisms. Recycled milled glass fillers were employed to improve delamination resistance. Mechanical and acoustic emission results were correlated with field emission scanning electron microscope images.

Low-cost, simple preparation and outstanding energy density of glass fiber reinforced PVDF polymer flexible composites

To make the product commercially viable and applicable, the inclusion of glass fiber filler with a low cost and medium dielectric constant (ε) is adopted as the filler. Synchronously, representative polyvinylidene fluoride (PVDF) with high permittivity and breakdown strength is selected as optimal polymer matrix. And surface modifying agent is employed as organic coatings to weaken the surface energy of glass fiber and boost the interfacial inter-action. An investigation of dielectric properties was conducted by preparing flexible composites consisting of various content of glass fiber. The ε of composites can be significantly enhanced in the PVDF composites with glass fiber, and the breakdown strength (BDS) is remained at a high level. Moreover, within a specific content range, glass fiber makes the ε and BDS of the material increase synchronously. This work provides a facile strategy for the development of excellent performance, simple preparation and low-cost flexible composites.

Preparation and sound insulation of honeycomb composite structures filled with glass fiber

AbstractHoneycomb composite with excellent mechanical–physical properties had attracted extensive attention. To achieve outstanding sound insulation while maximizing the high‐performance of honeycomb composite, this article reported a honeycomb composite structure filled with glass fiber (HFG) based on a paper‐making process and the corresponding sandwich structure. Pulping parameters, mechanical property, air permeability and sound insulation of HFG were analyzed. The results showed that the hanging index and settling height of glass fiber slurry were inversely proportional to the beating degree, which was beneficial for reducing the coefficient of variation (CV) of HFG with value of 4%–6%. The maximum improvement in tensile strength and bursting strength of HFG were 70% and 53%, respectively. In addition, sound transmission loss (STL) of HFG was proportional to cell size, density, filling amount and thickness of the honeycomb. Compared to HFG, sandwich structure consisting of HFG and glass fiber/hot melt fiber panels effectively improved STL, especially at low‐mid frequencies. It was also found that designing holes on the surface of sandwich structure could further improve STL in certain frequency bands. The structure offered a lightweight and high‐performance response for construction, transportation and infrastructure.Highlights This article designs a new type of honeycomb filled glass fiber via paper‐making process, aiming to improve the comprehensive performance of honeycomb. By the design of embedded structure, the maximum improvement in tensile strength and bursting strength of honeycomb were 70% and 53%, respectively. By designing perforated, embedded and laminated structures, sound insulation has been improved, while reducing material quality.

Physico‐mechanical and thermo‐mechanical analysis of zinc borate filled glass fiber reinforced polymer composites

AbstractThe potential benefits of using zinc borate powder as filler material in the production of glass fiber‐reinforced composites were explored in this study. The epoxy matrix was filled with zinc borate powder at 5%, 10%, and 15% by weight, as part of the hand lay‐up approach followed by a compression molding process. Ultrasonication was used to mix the epoxy resin with zinc borate fillers. Both the elemental composition and morphological characteristics were studied using a scanning electron microscope and energy‐dispersive X‐ray analysis. The composite's density, tensile behavior, flexural behavior, impact resistance, and hardness were all measured experimentally. The potential incorporation of zinc borate particles resulted in a modest reduction in the void contents, in addition to enhancing the interfacial bonding in glass fiber‐reinforced composites as also a significant improvement in both the mechanical and thermal properties of the hybrid composites produced. The 10 wt.% zinc borate‐ filled glass fiber‐reinforced composites exhibited a significant rise in both ultimate tensile strength (227 MPa), ultimate compressive strength (239 MPa), and ultimate flexural strength (406 MPa) compared to the unfilled counterpart. The performance of the laminated composites was greatly improved by adding zinc borate powder particles to the matrix.Highlights In the present work glass fiber was reinforced with zinc borate to explore the morphological, mechanical, and thermal properties. Ultrasonication was used to mix the epoxy resin and zinc borate fillers and the composites were manufactured by compression molding process. The addition of zinc borate resulted in an increase in tensile strength, flexural strength, and compressive strength. The thermal stability of the composites was increased by the addition of zinc borate to the glass matrix. The good bonding between the matrix and fiber resulted in improvements in various properties.

Effect of alumina nano‐particles on collapse behavior and energy absorption of laterally loaded glass/epoxy composite tubes

AbstractDue to its exceptional mechanical and crashworthiness properties, lightweight nanocomposites have recently been used more and more in aviation, defense, nautical, and automotive applications. Nanocomposite cylinders could be effectively employed in this respect as energy‐absorbing components for decreasing the impact energy during vehicle crashes. The current work examined the crashworthiness response of nano‐alumina (Al2O3) filled glass fiber reinforced epoxy (GFRE) composite tubes using quasi‐static lateral compressive loads. Crushing profiles and crush force–deformation curves of all representative samples were recorded and discussed. The total absorbed energy (AE) and specific absorbed energy (SEA) for tested specimens were assessed. Furthermore, a multi‐attribute decision making (MADM) technique known as complex proportional assessment (COPRAS) was used to compute the optimum nano‐Al2O3 wt%. Based on the experimental results, the addition of 1, 2, and 3 wt% of nano‐Al2O3 enhanced AE by 7.69%, 18.14%, and 51.21% and SEA by 3.43%, 13.98%, and 39.84%, respectively. While deteriorations of 6.59% and 17.41% in AE and SEA, respectively, were recorded with the addition of 4 wt% of nano‐Al2O3. Overall findings showed that (GFRE) composite tubes with 3 wt% of nano‐Al2O3 have a special potential to absorb energy.Highlights The designed tubes, that is, GFRE tubes filled with 0, 1, 2, 3, and 4 wt% of nano‐alumina (Al2O3) were created using wet‐wrapping by hand lay‐up technique. The fabricated tubes were subjected to lateral compression loads to investigate their crashworthiness behavior. The crashing load and absorbed energy versus displacement responses for the laterally loaded tubes were exposed. The histories of deformation were also examined. Complex proportional assessment (COPRAS) was used to find the optimum nano‐Al2O3 wt%.

A comparative study on the mechanical properties of African teff and snake grass fiber-reinforced hybrid composites: effect of bio castor seed shell/glass/SiC fillers

Abstract The environmental awareness and sustainable nature of plant-based fibers have forced material researchers and automakers to use natural fibers instead of petroleum-based fibers for various industrial applications. The need for environmentally and biodegradable fibers has created a demand in the transportation industry. In this study, bio castor seed shell (C), glass fiber (G), and SiC (SC) fillers in a constant weight fraction (10 %) were reinforced separately with varying weight fractions (5–25 %) of African teff and snake grass fibers to improve the mechanical properties of the hybrid composites. Both African teff and snake grass fibers were subjected to alkaline treatment to remove amorphous elements such as hemicellulose, lignin, and wax, resulting in high surface roughness. The hybrid composites were fabricated by the compression molding technique and their mechanical properties were characterized as per ASTM standards. The fractured surface of the treated fiber was examined by scanning electron microscopy. From the results, it was found that SC10SG20AT showed maximum mechanical properties compared to C10SG20AT and G10SG20AT due to higher load-bearing capacity of SiC filler. Therefore, SC10SG20AT can be recommended for lightweight applications.

Theoptical‐thermalmodeling of carbon black filled glass fiber reinforced poly‐ether‐ether‐ketone in laser assisted tape winding

AbstractTo facilitate the application of carbon black filled glass fiber reinforced poly‐ether‐ether‐ketone (CB‐GF/PEEK) prepreg in laser assisted tape winding (LATW), a finite element method is used to analyze the optical‐thermal characteristics of the following three prepregs with distinct laser absorption properties: (i) 0.5%CB (incomplete absorption), (ii) 2.74%CB (complete, single‐layer absorption), (iii) 4%CB (complete, near‐surface absorption). Thus, the energy distribution, temperature distribution and thermal accumulation are revealed, and the heating strategy is customized according to the laser absorption characteristics of each prerpeg. Then the feasibility of CB filled GF/PEEK prepreg in LATW is verified by manufacturing and testing NOL rings. Finally, the nip‐point irradiation scheme is optimized. The simulation results reveal a significant difference between the optical‐thermal characteristics of the 0.5%CB and those of the other two prerpegs. Benefited from the energy leakage, the 0.5%CB facilitated twice melting by thermal accumulation, along with a higher nip‐point temperature. Meanwhile, the mechanical performance tests of the NOL rings indicate a similar tensile strength of ~1300 MPa for the 0.5%CB and 4%CB, while the interlaminar strength of the 0.5%CB is slightly higher than that of the 4%CB. The latter result may be due to the higher nip‐point temperature of the 0.5%CB, which promotes resin diffusion and enhances the bonding strength. Finally, an optimized heating strategy with short laser length, vertical irradiation of the nip‐point is proposed, and is shown to reduce the ineffective thermal accumulation and ensured the suitability of Tape and Laminate temperature.

Improved thermal conductivity of poly(p-phenylene sulfide)/glass fiber composites via addition of polysiloxide-coated aggregated boron oxide and silane-treated graphene oxide

Poly (p-phenylene sulfide) (PPS) is a material with strong mechanical properties and chemical stability. However, PPS has a low thermal conductivity of 0.18 W/m•K, which limits its applications in fields requiring heat dissipation properties. In this work, to improve the mechanical and thermal properties, aggregated boron nitride (ABN) and graphene oxide (GO) fillers were added into the PPS/glass fiber (PPS/GF) system with proper treatment. ABN was covered with amine-functional polysiloxide and heat-treated to withstand and maintain the morphology after the composite molding process. Additionally, GO underwent 3-mercaptopropyl trimethoxysilane (MPTMS) treatment (MGO) to enhance the interface adhesion between the glass fiber filler and PPS matrix. By adding PSZABN and MGO into the PPS/GF system, the mechanical properties, storage modulus, and tensile strength were improved, and the thermal conductivity of the PPS/GF@20PSZABN@10MGO composite was 1.18 W/m•K, which is 6.55 times improved than that of pristine PPS.

The Effect of Powder and Emulsion Binders on the Tribological Properties of Particulate Filled Glass Fiber Reinforced Polymer Composites.

Investigations into polymer composites are mainly focused on properties dependent on glass fiber reinforcement and particulate fillers. In the present study, the effect of the binder was examined. The specimens were produced with two types of epoxy resin, with similar numbers of glass mat layers and similar proportions of quartz powder added. However, one group was fabricated with an emulsion binder in the glass mats and another group with a powder binder. Attention was concentrated on the tribological properties of the as-prepared composites, though their strength was examined as well. The hardness of the Sikafloor matrix was found to be much more sensitive to the applied binder than that of the MC-DUR matrix. No direct correlation between the microhardness and the specific wear rate was observed and increasing the particulate filler proportion did not cause a direct increase of the specific wear rate. In particular, the highest specific wear rate, around 350 J/g, was reached for both matrices with a 1% quartz addition when the emulsion binder was applied, while in the case of the powder binder it was with 6% quartz with the MC-DUR matrix, and there was no quartz addition with the Sikafloor matrix. The highest microhardness, HV0.5 = 25, in turn, was reached for the mats with the emulsion binder in the Sikafloor matrix with an addition of 10% quartz powder, while the highest friction coefficient was exhibited in the composite with the MC-DUR matrix, when 1% of the quartz powder and the emulsion binder were applied.

Promoted Li+ conduction in PEO-based all-solid-state electrolyte by hydroxyl-modified glass fiber fillers

Promoted Li+ conduction in PEO-based all-solid-state electrolyte by hydroxyl-modified glass fiber fillers

Manufacturing and toughening effects on the material properties of wind turbine blade adhesives

Hybrid adhesives can be developed using commercially available adhesive materials and customized to the required loading conditions. In this paper, SPABOND™ 820HTA (non-toughened) and SPABOND™ 840HTA (toughened) adhesives are hybridized by two strategies and fabricated by machine and manual mixing methods. The manufacturing and hybridization effects on the bulk adhesive properties are evaluated by dynamic mechanical analysis, quasi-static tensile, V-notch shear and single-edge-notch bending tests. X-ray micro-computed tomography, digital image correlation technique, high speed camera and scanning electron microscopic images are used for assessing the manufacturing quality, computing the full-field displacement and strain, and failure analysis. By considering the manufacturing methods, the measured properties are less influenced by the presence of voids but dependent on the glass fiber filler orientation. The adhesive toughening method improves the strain to failure and tensile toughness, decreases the strength and modulus and no significant effect on the glass transition temperature.

Investigation of physical, mechanical, and thermal properties of glass fiber reinforced polymer composites strengthened with KH550 and KH570 silane-coated silicon dioxide nanoparticles

Silicon dioxide (SiO2) nanoparticles can be used as reinforcing material for composites due to their favorable characteristics. However, they are commonly subjected to surface treatments with silane coupling agents to achieve fine dispersibility and better mechanical interlocking at interface. In this study, the silane-coated SiO2 nanoparticles (as received) were used as secondary reinforcement without applying additional silane treatment process. KH550 and KH570 silane-coated SiO2 nanoparticles were dispersed, respectively, into polymer matrix, and then the modified matrix was reinforced with glass fibers. Silanized SiO2 filled glass fiber reinforced polymer (GFRP) nanocomposites were investigated for physical, mechanical, morphological, and thermal properties. Depending on the nanoparticles' ratio and silane coating, the increments were obtained till 10% for tensile strength, between 18.40% and 75.26% for flexural strength, and till 81% for impact strength. SEM confirmed that the enhancements could be attributed to the improved interfacial adhesion between the modified matrix and fiber reinforcements. The void contents within the polymer nanocomposites decreased by 38%–54% compared to a pure one. DSC and TGA examinations revealed that silanized SiO2 nanoparticles provided a better curing behavior (10% increase in Tg for 3 wt.% KH550-SiO2) and improved thermal stability for the GFRP composites (increase in Tend values by 50–70°C). Generally, KH550 silane-coated SiO2 has provided enhanced interface strengthening, leading to better characteristics for GFRP composites since the amino functional groups contained in KH550 have more favorable integration with epoxy matrix.