Effect Of Hollow Glass Microspheres Research Articles

Effect of hollow glass microspheres on transverse properties of carbon fiber reinforced epoxy composites

AbstractHollow glass microsphere (HGM)—based composites are gaining popularity in materials research due to their ability in altering material characteristics drastically. The current study investigates HGMs filled carbon fiber reinforced epoxy (CE) composites on transverse properties, aiming for aerospace and defense applications mainly in composite pressure vessels. Unidirectional laminates of Carbon/Epoxy with varying HGM percentages (0.2, 0.4, 0.6, 0.8, 1.0 wt. %) were wounded onto a flat‐plate mandrel using a 4‐axis filament winder, along with a baseline sample without HGM for comparison. The glass transition temperature (Tg) and thermal stability were analyzed by carrying out dynamic mechanical analysis and thermogravimetric analysis. The fracture mechanism of the samples loaded under tension was investigated using FESEM. Experimental results indicate reduction in density with increase in HGM content, up to 0.4% HGM there is increase in transverse tensile strength of 25% compared to baseline and further increase in HGM content, decrease trend is observed. 30% decrease in transverse compressive strength is observed compared from baseline to 1.0 wt. % of HGM. No significant change was noticed in the thermal stability and Tg on introduction of HGM. Microscopy images of fractured samples revealed effective physical interaction and dispersion of the HGM within the matrix.Highlights Transverse mechanical properties are tested to know the influence of HGM filler on filament wound composites. Density of the composite decreases with increase in HGM content. Thermal stability and Tg shows less change on introduction of HGM in composites.

Effect of hollow glass microspheres (HGM) on improving self-heating capability of cement composites exposed to various deterioration conditions

Cement-based self-heating composites play a crucial role in addressing the need for intelligent road and pavement systems capable of efficient de-icing in severe weather conditions. However, the self-heating capability of these composites can be adversely affected by various deteriorating factors such as water ingress, nitric and sulfuric attacks, and freeze-thaw conditions. In this study, we propose the use of hollow glass microspheres (HGM) to enhance the self-heating capability of cement composites exposed to such deteriorating conditions. The initial investigation focused on observing the effects of HGM incorporation on changes in compressive strength, electrical conductivity, and thermal conductivity. Subsequently, the self-heating capability of these composites was systematically examined under cyclic heating conditions following exposure to deterioration factors. Microstructural analysis, including mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM), was conducted. The results indicated that the inclusion of HGM can effectively safeguard the conductive networks from external solutions, thereby preventing potential disconnection of these networks. Consequently, the incorporation of HGM is anticipated to enhance both the electrical stability and self-heating capability of cement composites exposed to diverse deteriorating conditions.

Acoustic Characterization of Transmitted and Received Acoustic Properties of Air-Coupled Ultrasonic Transducers Based on Matching Layer of Organosilicon Hollow Glass Microsphere.

An air-coupled transducer was developed in this study, utilizing hollow glass microsphere-organosilicon composites as an acoustically matching layer, which demonstrated outstanding acoustic performance. Firstly, a comparison and analysis of the properties and advantages of different substrates was carried out to determine the potential application value of organosilicon substrates. Immediately after, the effect of hollow glass microspheres with different particle sizes and mass fractions on the acoustic properties of the matching layer was analyzed. It also evaluated the mechanical properties of the matching layer before and after optimization. The findings indicate that the optimized composite material attained a characteristic acoustic impedance of 1.04 MRayl and an acoustic attenuation of 0.43 dB/mm, displaying exceptional acoustic performance. After encapsulating the ultrasonic transducer using a 3D-printed shell, we analyzed and compared its emission and reception characteristics to the commercial transducer and found that its emission acoustic pressure amplitude and reception voltage amplitude were 34% and 26% higher, respectively. Finally, the transducer was installed onto a homemade ultrasonic flow meter for practical application verification, resulting in an accuracy rate of 97.4%.

Effect of hollow glass microsphere on the processing and flame retardancy of intumescent flame retardant polypropylene composites prepared by selective laser sintering

Effect of hollow glass microsphere on the processing and flame retardancy of intumescent flame retardant polypropylene composites prepared by selective laser sintering

Durability and Thermal Behavior of Functional Paints Formulated with Recycled-Glass Hollow Microspheres of Different Size.

This study aims to assess the effect of hollow glass microspheres of different sizes derived from glass industry waste on the durability and thermal behavior of waterborne paint. The coatings were characterized by electron microscopy to investigate the distribution of the spheres and their influence on the layer morphology. The impact of the various glassy spheres on the mechanical feature of the coatings was assessed using the Buchholz hardness test and the Scrub abrasion test. The role of the spheres in altering the durability of the samples was analyzed by the salt spray exposure test and the electrochemical impedance spectroscopy measurements. Finally, a specific accelerated degradation test was carried out to explore the evolution of the thermal behavior of the composite coatings. Ultimately, this work revealed the pros and cons of using hollow glass spheres as a multifunctional paint filler, highlighting the size of the spheres as a key parameter. For example, spheres with adequate size (25-44 µm), totally embedded in the polymeric matrix, are able to reduce the thermal conductivity of the coating avoiding local heat accumulation phenomena.

Effect of Hollow Glass Microsphere (HGM) on Impact and Flexural Properties of High-Density Syntactic Foam Based Epoxy Composites

Syntactic foam composite offers versatile application possibilities in marine, structural, aerospace industries due to their good tensile, flexural, and compressive strength, corrosive resistance, high specific strength and modulus, light weight nature. Their porous structure is by mixing hollow particles called microspheres as fillers into matrix materials such as polymer, metal or ceramic etc. In this study, a high-density hollow glass microsphere is used to fabricate syntactic foam by mixing it with epoxy resin. Five different compositions 5, 10, 15, 20 and 25 vol% of hollow glass microspheres were varied in fabricating the syntactic foam. Impact and flexural properties were investigated on the syntactic foam. All the compositions of the volume fraction variations of hollow glass microsphere content in the syntactic foam increased more than the neat epoxy. The highest impact resistance, flexural strength and flexural modulus is at 5 vol%, 113.12 kJ/m2, 86.7 MPa, and 80 GPa respectively with 25.2%, 38.29%, and 33.25% increase respectively more the neat epoxy while the specific impact and flexural strength is at 25 vol% with 53.78% and 57.77% increase respectively more than the neat epoxy.

Effect of Hollow Glass Microspheres with Different Contents and Types on Properties of Polypropylene Composites

AbstractIn this paper, hollow glass microspheres (HGM) reinforced polypropylene (PP) composites were prepared. The effects of the type and content of HGM on the mechanical properties of the composite materials were investigated. It is found that the introduction of HGM leads to a decrease in the density of the composites, where the smallest density is 0.85 g cm−3. The tensile, bending, and impact strengths of the HGM/PP composites are slightly lower than those of pure PP resin. For a given type of HGM, as the filler content increases, the tensile properties of the HGM/PP composite decrease. A similar trend is observed in the impact strength, however, it is not observed in the bending performance. The mechanical properties of the HGM/PP composites are not only affected by the density of HGM fillers, but also by its content. The maximum bending modulus of the composites could be 24 % higher than that of the pure PP resins. In addition, the PP sample with HGM modified with γ‐aminopropyl triethoxysilane (KH550) showed promising interfacial bonding strength.

Loading Effect of Hollow Glass Microsphere (HGM) and Foam Microstructure on the Specific Mechanical Properties and Water Absorption of Syntactic Foam Composite

AbstractEpoxy syntactic foams (SF) filled with hollow glass microspheres (HGM) were prepared by simple resin casting method and characterization in this study. The effect of varying the amount of HGM on the specific mechanical and water absorption properties of SF composites were investigated. Five different composition of SF (SFT60-0.5 to SFT60-2.5) were compared with the neat epoxy matrix. The wall thickness of the microballoons differ because of its different percentile size distribution (10th, 50th and 90th), which reflects in its density variation. The results show that the specific tensile and flexural strength increases with an increasing filler (HGM) content. The density of SF filled with HGM reduces with increasing volume fraction of filler content. Scanning electron microscopy was done on the failed samples to examine the fractured surfaces. The water absorption capacity of the SF was also investigated as it relates to the HGM volume fraction variation. All the syntactic foam composition shows a better diffusion coefficient capacity than the neat epoxy resin. This makes it applicable in structural purposes and several marine application products such as Autonomous Ultimately Vehicle (AUV).

The effect of hollow glass microspheres, carbon nanofibers and activated carbon powder on mechanical and dry shrinkage performance of ultra-lightweight engineered cementitious composites

Hollow glass microspheres (HGMs) containing a large amount of recycled glass are used to develop ultra-lightweight engineered cementitious composites (ECCs), which are more sustainable comparing to standard ECC. Carbon nanofibers (CNFs) and activated carbon powder (ACP) were used to improve the mechanical and shrinkage properties of ultra-lightweight ECCs. The parameters investigated were flowability, compressive strength, flexural toughness, strain-hardening performance, and dry shrinkage. ECCs exhibited a density of 1449–1282 kg/m3 by replacing 60%–100% of its fly ash with HGMs, classified as ultra-lightweight ECCs. The inclusion of HGMs improved the flowability but reduced the compressive and flexural strength of composites. Results confirm the feasibility of developing an ultra-lightweight ECC with a compressive strength of 28.7 MPa and a dry shrinkage strain of less than 1250 microstrain when the composite is reinforced with CNFs. It is also shown that CNFs is more effective than ACP to control dry shrinkage and to overcome the adverse effect of HGMs inclusion on flexural performance of ECCs.

Morphology and mechanical characterization of carbon nanotubes/epoxy based material filled with hollow glass microsphere

The hollow glass microsphere (HGM)/carbon nanotubes (CNTs)/epoxy composite foam are fabricated by solution casting of functionalized CNT and functionalized HGM-epoxy dispersion. Five weight ratio configurations (2, 4, 6, 8, and 10 wt%) of functionalized–HGMs were considered and compared with 0.1 wt% CNT/epoxy to investigate the effects of hollow micro sphere enrichment. This study investigate the effect of hollow glass microspheres (HGM) on the compressive strength and storage modulus of CNT modified epoxy resin. The results revealed that the incorporation of HGM improved the damping performance evidently and broadened damping temperature range. TEM image of the composite show a better dispersion of CNTs in epoxy matrix. SEM micrographs of composite foams are investigated to determine structure development and CNTs, HGM dispersion, with regard to experimental results, especially compression test.

Effect of hollow glass microsphere on the flame retardancy and combustion behavior of intumescent flame retardant polypropylene composites

Nowadays, increasing the fire safety of polypropylene (PP) is an important research direction. In this article, the investigation mainly focuses on the effect of hollow glass microsphere (HGM) on improving the fire safety of PP/intumescent flame retardants (IFR) composites. The flame retardancy, smoke suppression and thermal stability of PP/IFR/HGM system were studied by limiting oxygen index (LOI), vertical burning (UL-94), cone calorimeter tests (CCT) and thermogravimetric analysis. All the results demonstrated that the incorporation of HGM into PP/IFR system can clearly improve the fire safety of PP/IFR materials. The result of the LOI can be as high as 36.5% with only 1 wt% HGM and 24 wt% IFR addition. Scanning electron microscope–energy-dispersive spectrometer (SEM–EDS) and CCT results illustrated that during the combustion, HGM would migrate onto the surface of the sample to form a compact char layer and prevent further combustion of the material. Furthermore, the CCT results indicated that HGM can slow down the peak heat release rate (from 94.9 to 61.6 kW/m2) and make the total smoke release (TSR) decrease from 1210 m2/m2 (PP/IFR) to 544 m2/m2 (PP/IFR/HGM), reduced by 55.0%. In addition, HGM can improve the thermal stability of PP/IFR systems.

High specific strength hybrid polypropylene composites using carbon fibre and hollow glass microspheres: Development, characterization and comparison with empirical models

Synergistic effect of hollow glass microspheres (HGM) addition on various physical and mechanical properties of short carbon fibre (SCF) reinforced polypropylene (PP) hybrid composites were investigated. Hybrid composite samples were prepared by melt mixing PP, maleic anhydride-grafted-PP (MA-g-PP), SCF and surface-treated HGM. Effect of varying concentration of HGM (0–40 wt%) and SCF (0, 5, 8 wt%) on various physical and mechanical properties was analyzed. HGM showed an impressive positive impact in reducing the overall density of composites with its increasing concentration. Among all the different composite formulations, hybrid composite incorporated with 10 and 8 wt% HGM and SCF showed the highest tensile and flexural strength (up by ∼110 and ∼112% over pure PP). Interestingly, the specific tensile strength with only 8 wt% SCF was observed to be significantly high (∼100 MPa/g/cm3) and similar to commercial PP composites containing much higher (40 wt%) fibre contents. Empirical estimates of tensile modulus evaluated using several available micromechanical models, indicated that a combination of Ishai and Cohen (upper bound) and Halpin-Tsai models which assume a perfect particle- and fibre-matrix interfacial adhesion, are in excellent agreement with results of this investigation. Morphological analysis of cryo-fractured surfaces revealed good dispersion and distribution of both HGM and SCF with very negligible broken HGM fillers.

Plasma-Chemical Modification of Facing Composite Material on the Basis of Hollow Glass Microspheres with Decorative Protective Coating

The paper considers plasma-chemical modification of facing composite material on the basis of hollow glass microspheres with decorative protective coatings. It is shown that the technology of obtaining decorative protective coating by the method of plasma reflow is highly efficient and energy-saving, which will allow competition with traditional technologies and significantly reduce the cost of finishing work. Compositions of decorative protective coatings based on high-alumina refractory and liquid glass have been developed. It was revealed that the use of high-alumina refractory crushed material in the intermediate layer makes it possible to reduce the number of microcracks and eliminate the consequences of high-temperature impact on the matrix of fine-grained concrete. The positive effect of hollow glass microspheres on the minimization of thermal shock was established. The results of the investigation of the effect of plasma-chemical modification on the phase composition and structural features of the facing composite material on the basis of hollow glass microspheres with a decorative protective coating are presented. The regularity of layer-by-layer variation of the phase composition and the macro- and microstructure of the decorative protective coating of the facing composite material is established. It is shown that the upper layer is represented by Na–Ca–Al–Si glass, the middle glass ceramic layer is represented by the glass phase and α and β modifications of aluminum oxide, and the lower dehydration layer is represented by dehydration products of hydrosilicates and α and β modifications of alumina. High-temperature action of the plasma jet intensifies thermal diffusion, which in turn leads to a redistribution of oxides along the thickness of the decorative protective coating.

Fabrication and characterization of an engineered cementitious composite with enhanced fire resistance performance

This study evaluated the fire resistance of a lightweight engineered cementitious composite under elevated temperature up to 900 °C. To achieve lightweight, waste recycled hollow glass microspheres, which comprise 45% of waste glass were obtained as an ultra-high-performance lightweight filler. And carbon nanofibre was added to maintain the mechanical properties of engineered cementitious composite while reducing the weight. This study aims to thoroughly understand the effect of hollow glass microsphere, carbon nanofibre, and their combination to the fire resistance of engineered cementitious composite. Three different types of hollow glass microspheres and four different types of carbon nanofibers were conducted in this research. The results showed that engineered cementitious composite contains both hollow glass microsphere and carbon nanofibre presented high fire resistance, which is able to remain 50% of original strength when exposed to high temperature at 900 °C. The compressive strength of composite was found to be slightly influenced with using hollow glass microsphere, although the total densities were reduced. Carbon nanofibre contribute to the composite’s strength of both normal and lightweight engineered cementitious composite and it is able to enhance mechanical performance when the samples are under elevated temperatures. Microscopy study found that carbon nanofibre contribute to the composite rehydration at high temperature. The work provides a promising way to develop lightweight engineered cementitious composite with high mechanical performance and fire resistance, and proved the possibility of partially replacing cementitious material with hollow glass microsphere.

The addition effect of hollow glass microsphere on the dispersion behavior and physical properties of polypropylene/clay nanocomposites

ABSTRACTPolypropylene (PP) nanocomposites have been widely researched for last decade due to its high mechanical property and multiple usages in various industrial fields from automobile to consumer packaging. Dispersion of nanoclay in polyethylene and PP is the key factor due to their hydrophobic property. Adding surfactant or introducing a polymer with a functional group, and modifying a natural clay with organic ions have been tried to achieve the better dispersion of clay in polymer matrix. In this study, the PP/clay nanocomposite with maleic anhydride grafted PP and hollow glass microspheres (HGMs) at various compositions were prepared and characterized. The addition of HGMs to PP/clay nanocomposites significantly improved the tensile stress at yield point except 7 wt % of HGMs. It is assumed that this could be due to not only the reinforcing effect of HGMs in PP, but the crushing effect of HGMs on the clay resulting in interlayer increase of clay as well. The barrier properties was also found to be improved about 32% max resulting from the better dispersion and presence of HGMs. It could be assumed that the HGMs could act as a ball creating a ball milling crush force to achieve the better dispersion of clay in the polymer and improve nanocomposite performance. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47476.

Effect of Hollow Glass Microspheres on the Morphology, Rheology and Crystallinity of Short Bamboo Fiber-Reinforced Hybrid Polypropylene Composite

Light-weight and high-strength polymer composites have attracted the special attention of automotive and aerospace sectors since they offer advantages such as less fuel consumption and higher fuel efficiency. In the present study, an effort has been made to prepare such polymer composites using natural fiber and very low-density hollow inorganic particles. The use of hollow glass microspheres (HGM) as a potential filler particle for making light-weight hybrid polymer composites was investigated. Polypropylene (PP) and maleic anhydride-grafted-polypropylene (in 9:1 ratio) constituted the base matrix (BM). For strength reinforcement, alkali-treated short bamboo fibers (SBF) were employed, while for making the composite material light in weight, HGM were incorporated. Silane treatment of HGM by (3-aminopropyl)triethoxysilane was performed to enhance interfacial adhesion with BM. Adequate wetting of HGM and SBF was evident from the SEM images of cryo-fractured samples. A 14% increase in tensile strength was observed in comparison to virgin PP for the composite with 5 wt.% HGM, and a desirable decrease in density was observed for all the composite samples with increasing HGM content. Improvement in hardness but a marginal decrease in impact strength due to HGM fillers was observed. Rheological analysis of the composite melt samples showed an apparent increase in the complex modulus with increasing HGM content. Thermal analysis of the composites revealed a significant impact of hybrid fillers on the crystallinity, with SBF showing a minimal effect while HGM reducing it significantly. Wide-angle x-ray diffraction spectra showed changes in the crystal structure of the composite with noticeable β-form peaks.

The effect of hollow glass microspheres on the properties of high silica glass fiber fabric/liquid silicone rubber composite sheet

In this study, high silica glass fiber fabric/liquid silicone rubber (HSGFF/LSR) composite sheet filled with hollow glass microspheres (HGM) was prepared. The effects of HGM content on the mecha­nical, thermal insulation and dynamic mechanical properties of the composite sheet were investigated. The results showed that the compatibility and interfacial properties between HGM and the matrix were improved after the HGM was treated with a silane coupling agent, KH550. Composite, in which the HGM content was 7 % by weight, shows the most advantageous mechanical, insulating and damping properties.

Effect of hollow glass microsphere (HGM) on the dispersion state of single-walled carbon nanotube (SWNT)

Abstract Single-walled carbon nanotube (SWNT) loaded polypropylene (PP) based syntactic foam is fabricated by melt mixing method. In order to evaluate the effect of hollow glass microsphere (HGM) on the dispersion state of SWNT and to identify the optimal weight of HGM, various analysis is performed. Based on the comprehensive result analysis, it is concluded that HGMs weight between 1 and 7 wt% shows the best performance. At low weight of HGMs (0.1–0.5 wt%), HGMs act as nucleating agent to escalate the agglomeration of SWNT, while high load of HGMs tend to aggregate each other, hindering the formation of SWNT percolation network.

The synergistic effect of hollow glass microsphere in intumescent flame-retardant epoxy resin

A series of flame-retardant epoxy resin (EP) composites, with different mass ratio of intumescent flame-retardant (IFR) and hollow glass microspheres (HGM), have been prepared. The synergistic flame-retardant effects of HGM between IFR in EP blends have been examined through several conventional methods, such as limiting oxygen index (LOI) test, UL-94 test, cone calorimeter test (CCT), scanning electron microscopy (SEM), and thermogravimetric analysis (TG), respectively. The LOI and UL-94 results show that when 2.0 mass% IFR is replaced by HGM, the LOI value can be increased to the maximum value of 34.7 among all samples. The data obtained from the CCT test indicate the peak value of heat release rate of EP/IFR/HGM sample with 2.0 mass% HGM reduced to 177.6 from 851.1 kW m−2 (pure EP). The digital photographs and SEM of char residues after CCT give positive evidence of the synergistic flame-retardant effects between HGM and IFR. Firstly, HGM could promote the formation of dense and compact charred layers. Secondly, it could prevent the charred layers from cracking. The TG results reveal that EP/IFR/HGM samples show higher thermal stability at high temperature than EP/IFR sample.

Synergistic effects between hollow glass microsphere and ammonium polyphosphate on flame-retardant thermoplastic polyurethane

It is mainly studied that the smoke-suppression properties and synergistic flame-retardant effect of hollow glass microsphere (HM) in flame retardant thermoplastic polyurethane (TPU) composites based on ammonium polyphosphate (APP) as a flame-retardant. Also, the smoke suppression properties and flame-retardant effect were investigated by smoke density test (SDT), cone calorimeter test (CCT), limiting oxygen index, and thermogravimetric analysis, separately. The char residues left after CCT were examined by scanning electron microscopy. The data of SDT shows that HM could effectively decrease smoke production of TPU composites. The results of CCT reveal that the system of APP/HM could reduce heat release rate, smoke production rate, and total smoke release. It is shown that APP/HM is a good system with smoke-suppression and synergistic flame-retardant properties in flame-retardant TPU composites.