Alumina Trihydrate Research Articles

Hazardous dusts from the fabrication of countertop: a review

Artificial countertop materials, including solid surface composites (SSC) and engineered stone (ES) may pose significant pulmonary health risks for workers who manipulate them. These materials have rapidly become popular in the multibillion-dollar countertop industry, rivaling that of natural materials such as granite and marble due to their variety of desirable esthetic qualities and reduced costs. Both SSC and ES consist of a mineral substrate bound together in a polymer matrix. For SSC the mineral is about 70% aluminum trihydrate (ATH) while ES contains up to 95% crystalline silica by weight. Both materials emit airborne dusts when being manipulated with power tools during the fabrication process. Several deaths and dozens of cases of silicosis have been identified worldwide in workers who fabricate ES, while a single case of fatal pulmonary fibrosis has been associated with SCC dust exposure. This review examines the current state of knowledge for both SSC and ES regarding the composition, particle emission characteristics, workplace exposure data, particle constituent toxicity, and possible methods for reducing worker exposure.

Physical Properties of Glass-Fibre-Reinforced Polymer Filled with Alumina Trihydrate and Calcium Carbonate.

Gutters made of glass-fibre-reinforced polymer (GFRP) are usually produced with a three-millimetre thickness. The fillers are mixed into unsaturated polyester (UP) resin, which is intended to make the composite material more affordable. This study aims to examine the effects of the addition of alumina trihydrate (ATH), calcium carbonate (CC), and a mixture of ATH and CC of 15 and 30 parts per hundredweight of resins (PHR) on the material properties of the three-millimetre-thick three-layered GFRP composites. The properties observed included physical properties, namely, specific gravity and water absorption, chemical properties such as burning rate, and mechanical properties such as hardness, flexural strength, and toughness. The effects of the fillers on the voids and interfacial bond between the reinforcing fibre and matrix were analysed using the flexural fracture observation through scanning electron microscopy (SEM). The results showed that the addition of fillers into the UP resin led to an increase in the density, hardness, flexural strength, modulus of elasticity, and toughness but a decrease in water absorption and burning rate in a horizontal position. This information can be helpful for manufacturers of gutters made of GFRP in selecting the appropriate constituent materials while considering the technical and economic properties.

AC Corona Degradation of Silicone Rubber Nanocomposites at Low Air Pressure

Corona discharges get accelerated at low air pressure conditions leading to severe aging of the polymeric housing material, eventually causing the failure of the insulator. In this article, the effect of ac corona on different silicone rubber (SiR) micro- and nanocomposite samples at low pressure is studied. Micro alumina trihydrate (ATH), nano-titanium dioxide (TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ), and nano-silica are used as filler materials in varying concentrations. This article compares the filler materials for nanocomposite preparation based on their performance in low-pressure conditions. It is observed that the decrease in pressure results in increased corona discharges and loss of hydrophobicity in the samples. The formation of carboxylic acid is evident from the Fourier transform infrared spectroscopy (FTIR) for the treated samples. The performance of silica nanocomposite with 5 wt% loading is better than the silica nanocomposite with 3 wt% loading. Crack width, surface roughness, and physicochemical changes were significantly reduced in silicone dioxide filled SiR (SSR <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5%</sub> ) when compared to other silica and TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -filled samples at low pressure. The SiR samples filled with 5 wt% nano-silica perform better in terms of resisting corona-induced degradation at low pressure.

Superhydrophobic nanocomposite coatings based on different polysiloxane matrices designed for electrical insulators

The present paper describes for the first time the influence of three different kinds of polysiloxane as hydrophobic agent on superhydrophobic coatings for electrical insulators: a trimethoxy (2,2,4-trimethyl pentyl)-based silane; a mixture of methyl methoxy siloxane with methylsilsesquioxane; a mixture of dimethyl siloxane, methylsilsesquioxanes and n-octyl silsesquioxanes. The polysiloxane properties were investigated by thermogravimetric (TGA) and hydrophobic (contact and sliding angles) analysis, indicating great differences on thermal properties and surface free energy. The polysiloxane binders were loaded with different sizes of microsized alumina trihydrate (ATH) and organophilic nanosilica functionalized with octyl-silane and polydimethylsiloxane (PDMS). The hydrophobicity of the coating was evaluated by water contact angle (WCA) and sliding angle (SA). The morphology and roughness of the coatings were investigated by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Moreover the superhydrophobic durability of the coatings was evaluated by water immersion, hydrophobicity recovery, hydrophobicity transfer and adhesion. The effectiveness of these materials as coatings for glass electrical insulator was evaluated by tracking and erosion resistance using the inclined plane test (IPT). The results showed that the polysiloxane based on a mixture of methyl methoxy siloxane with methylsilsesquioxanee loaded with ATH and PDMS-treated silica exhibited the most promising characteristics as high contact angle, self-cleaning ability, good adhesion to the substrate and low number of leakage current peaks during the tracking and erosion resistance test. Such characteristics can bring benefits on electrical insulators like reducing the formation of conductive surface paths and the consequent degradation of the coating by dry band arcs, increasing its resistance when exposed to the electric field.

Effect of hybrid carbon nanofillers at percolation on electrical and mechanical properties of glass fiber reinforced epoxy

AbstractMulti walled carbon nanotubes and graphene nanoplatelets are novel fillers possessing exceptional intrinsic characteristics, such as high aspect ratio, strength, and good compatibility. These fillers are integrated into a glass fiber reinforced epoxy using a pultrusion process with a mixing ratio of 2:3 to attain the synergetic effect. The electrical and mechanical properties of the composites containing combinations of multi walled carbon nanotubes (0.4 wt%), graphene nanoplatelets (0.6 wt%) and micron aluminum trihydrate (2 wt%) fillers is studied. Significant improvement in electrical and mechanical properties is achieved. This study reveals that the incorporation of hybrid carbon nanofillers into epoxy leads to improved dielectric constant, AC conductivity and mechanical properties as compared with the base epoxy composite with glass reinforcement. The AC conductivity increases from 10−9 to 10−1 S/m and dielectric constant from 3.6 to 100 due to carbon fillers. The mean tensile strength improves from 433 MPa of the base epoxy composite to 508 MPa in carbon‐filled composite. The compressive strength improves from 630 to 681 MPa due to incorporation of carbon fillers signifying the improvement in load transfer effectiveness. The effect of carbon fillers on the flexural strength and hardness is minimal. The experimental data on mechanical parameters have been validated using theoretical modeling and a good correlation is established.

A New Kinetic Modeling Approach for Predicting the Lifetime of ATH-Filled Silane Cross-Linked Polyethylene in a Nuclear Environment.

This study focuses on the degradation of a silane cross-linked polyethylene (Si-XLPE) matrix filled with three different contents of aluminum tri-hydrate (ATH): 0, 25, and 50 phr. These three materials were subjected to radiochemical ageing at three different dose rates (8.5, 77.8, and 400 Gy·h−1) in air at low temperatures close to ambient (47, 47, and 21 °C, respectively). Changes due to radio-thermal ageing were investigated according to both a multi-scale and a multi-technique approach. In particular, the changes in the chemical composition, the macromolecular network structure, and the crystallinity of the Si-XLPE matrix were monitored by FTIR spectroscopy, swelling measurements in xylene, differential scanning calorimetry, and density measurements. A more pronounced degradation of the Si-XLPE matrix located in the immediate vicinity of the ATH fillers was clearly highlighted by the swelling measurements. A very fast radiolytic decomposition of the covalent bonds initially formed at the ATH/Si-XLPE interface was proposed to explain the higher concentration of chain scissions. If, as expected, the changes in the elastic properties of the three materials under study are mainly driven by the crystallinity of the Si-XLPE matrix, in contrast, the changes in their fracture properties are also significantly impacted by the degradation of the interfacial region. As an example, the lifetime was found to be approximately halved for the two composite materials compared to the unfilled Si-XLPE matrix under the harshest ageing conditions (i.e., under 400 Gy·h−1 at 21 °C). The radio-thermal oxidation kinetic model previously developed for the unfilled Si-XLPE matrix was extended to the two composite materials by taking into account both the diluting effect of the ATH fillers (i.e., the ATH content) and the interfacial degradation.

Towards recycling of challenging waste fractions: Identifying flame retardants in plastics with optical spectroscopic techniques.

The use of plastics is rapidly rising around the world causing a major challenge for recycling. Lately, a lot of emphasis has been put on recycling of packaging plastics, but, in addition, there are high volume domains with low recycling rate such as automotive, building and construction, and electric and electronic equipment. Waste plastics from these domains often contain additives that restrict their recycling due to the hazardousness and challenges they bring to chemical and mechanical recycling. As such, the first step for enabling the reuse of these fractions is the identification of these additives in the waste plastics. This study compares the ability of different optical spectroscopy technologies to detect two different plastic additives, fire retardants ammonium polyphosphate and aluminium trihydrate, inside polypropylene plastic matrix. The detection techniques near-infrared (NIR), Fourier-transform infrared (FTIR) and Raman spectroscopy as well as hyperspectral imaging (HSI) in the short-wavelength infrared (SWIR) and mid-wavelength infrared (MWIR) range were evaluated. The results indicate that Raman, NIR and SWIR HSI have the potential to detect these additives inside the plastic matrix even at relatively low concentrations. As such, utilising these methods has the possibility to facilitate sorting and recycling of as of yet unused plastic waste streams, although more research is needed in applying them in actual waste sorting facilities.

Investigation of Ramped Compression Effect on the Dielectric Properties of Silicone Rubber Composites for the Coating of High-Voltage Insulation.

The incorporation of inorganic oxide fillers imparts superior dielectric properties in silicone rubber for high-voltage insulation. However, the dielectric characteristics are influenced by the mechanical stress. The effects of ramped compression on the dielectric properties of neat silicone rubber (NSiR), 15% SiO2 microcomposite (SSMC), 15% alumina trihydrate (ATH) microcomposite (SAMC) and 10% ATH + 2% SiO2 hybrid composite (SMNC) are presented in this study. The dielectric constant and dissipation factor were measured before and after each compression especially in the frequency range of 50 kHz to 2MHz. Before the compression, SSMC expressed the highest dielectric constant of 4.44 followed by SMNC and SAMC. After the compression cycle, SAMC expressed a better dielectric behavior exhibiting dielectric constant of 7.19 and a dissipation factor of 0.01164. Overall, SAMC expressed better dielectric response before and after compression cycle with dielectric constant and dissipation factor in admissible ranges.

Industrial Implementation of Aluminum Trihydrate-Fiber Composition for Fire Resistance and Mechanical Properties in Glass-Fiber-Reinforced Polymer Roofs.

It is difficult to obtain suitable fire resistance and mechanical properties for glass-fiber-reinforced polymer (GFRP) roof material in industrial applications. Although some efforts to improve the fire resistance properties of GFRP have been carried out, in practice this sometimes degrades the mechanical properties. Therefore, the base materials, such as filler and reinforcing fiber, must be appropriately combined to simultaneously improve both fire resistance and mechanical properties. The present study examines improvements in GFRP roof material by investigating the effect of aluminium trihydrate (ATH) as a filler and the combination of a chopped strand mat (CSM) with woven roving (WR) and stitched mat (STM) fibers as the reinforcement in a composite GFRP roof structure. The roof samples were prepared following industrial machine standards using the specified materials. The mechanical properties of GFRP were evaluated using tensile, flexural and impact tests, following ASTM D638, ASTM D790 and ASTM D256 standards, respectively. The fire properties were examined through fire tests following the ASTM D635 standard. The results show that the GFRP roof composed of CSM/WR fibers had a 40% higher tensile strength (103.5 MPa) compared with the GFRP roof without CSM fibers (73.8 MPa). The flexural strength of the GFRP roof with CSM/WR fibers was also 57% higher than the roof without fibers, with a ratio of 315.61 MPa to 201 MPa. With the use of CSM/WR fibers, the fire resistance also increased by 23%, resulting in a ratio of 4.31 mm/min to 5.32 mm/min. These results demonstrate that the combination of CSM/WR fibers as a reinforcement would be an excellent option for producing an improved GFRP roof with better industrial properties, especially when producing improved GFRP roofs using a continuous lamination machine.

Enhancement of electrical, mechanical and thermal properties of silicone based coating with aluminatrihydrate/silica for ceramic insulators

The present work explores durability enhancement in various properties of room temperature vulcanized silicone rubber (RTV-SiR) coating with the incorporation of alumina trihydrate (ATH) and silica (SiO2) fillers. Test samples i.e., neat RTV-SiR, RTV-SiR +10% μSiO2, and RTV-SiR filled with micro-ATH/SiO2 (10% each) were chosen for experimentation. Long-term (10,000 h) lab aging of composite coatings is performed under bipolar direct current (DC) voltage with simulated environmental stresses in a test chamber. The effect of fillers against stresses is quantified through characterization results comparison of filled composites with unfilled RTV-SiR samples. Moreover, the polarity effect on degradation is evaluated through the relative performance of each composite under the positive and negative polarity of the voltage. Findings revealed that samples filled with a mixture of additives bring enhanced improvement into the base matrix of RTV-SiR. Amongst unfilled and micro-silica filled specimens aged under positive DC, the samples S-3 with combined silica-ATH fillers offered superior hydrophobic behavior showing hydrophobicity class HC3 and demonstrated a minimum final leakage current of 6.13 μA. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) results showed relatively lower variations in the chemical and morphological structure of cross-filed specimens (S-3). Furthermore, results of mechanical properties (tensile strength, elasticity, and weight) show a significant loss, whereas the hardness of composite increased with aging. Hybrid samples (S-3) exhibited the minimum deviation of 29.77% and 43.12% in tensile strength and elongation-at-break (EAB), respectively under positive DC voltage. Similarly, it shows enhanced resistance against weight loss and change in hardness due to aging. Moreover, thermogravimetric analysis (TGA) confirmed that filled composite gets enabled to offers the least alteration in thermal properties. In the context of the polarity, positive DC voltage incurred more devaluation of desirable properties as compared to negative polarity.

A microstructure image-based numerical model for predicting the fracture toughness of alumina trihydrate (ATH) filled poly(methyl methacrylate) (PMMA) composites

A novel finite element model is proposed here for predicting the fracture toughness using real microstructural images and accounting for several parameters that can affect the crack propagation such as filler content, particle shape, particle agglomeration and particle debonding. The damage energy prior to the catastrophic failure of the whole microstructure is taken as the energy required for crack initiation, and the fracture toughness is calculated using the concept of a critical crack size. The predictions agree well with the measured values of the critical energy release rate at 20 °C as a function of both volume fraction and mean particle size. In addition, a parametric study showed that an increase in interfacial cohesive energy leads to higher fracture energies at 60 °C. The proposed methodology shows great potential and can be widely applied to other particulate composites, enabling industry to cost-effectively develop tougher, hence safer and more durable, particulate composites.

CO2 Capture and Crystallization of ATH Using Sodium Aluminate Solution in a Bubble Column Scrubber

In this work, sodium aluminate alkaline solution was used to capture CO2 in a continuous bubble column scrubber and aluminum tri-hydrate (ATH) precipitates were produced. As the sodium carbonate could be recycled after the filtrated solution was crystallized by evaporation, a novel CO2 capture process was developed successfully. There were five experimental operation variables, including solution flow rate (A), concentration of the solution (B), gas flow rate (C), CO2 gas concentration (D), and liquid temperature (E), with four levels to each variable. The influence of each variable on absorption efficiency (EF), absorption rate (RA), absorption factor (φ), mass transfer coefficient (KGa), and precipitation rate (RP) in a steady state was explored in this study. The Taguchi experimental design was adopted, and 16 experiments were performed; as the optimum operating conditions found in Taguchi analysis required further verification, there were a total of 21 experiments in the end. According to S/N analysis, the overall order of importance was D &gt; A = B &gt; C &gt; E, meaning D (CO2 concentration) was most important and E (liquid temperature) was least important. In addition, the result also showed that the Rp was 1.25–2.0 times higher than the RA. The obtained powder was mainly ATH according to XRD analysis, with the crystal size ranging between 8.14 and 27.97 nm. However, the BET analysis showed its particle size range being 17.6–283.7 nm, indicating agglomeration for primary particles. The SEM analysis showed that there were flower-like, irregular, urchin-like, elongated, and amorphous particles. The solutions from five groups of optimum conditions were used to recycle the sodium carbonate experiments. After evaporation and crystallization of the filtrated solutions, the energy loading was found to be 1.70–2.56 GJ/t-solvent, illustrating the superiorities of low energy consumption. The precipitated powders were verified to be sodium carbonate by FTIR, which is a valuable constituent.

Role of polymer‐filler interaction on Mg(OH)2 and alumina trihydrate‐loaded ethylene propylene diene monomer based polymer composite for high voltage insulation application

AbstractUse of polymer composite as a high voltage insulator material is currently under investigation for its commercial application, longer durability, and cost effectiveness. This work probes the effect of polymer‐filler interaction on mechanical, morphological, thermal and dielectric properties of ethylene propylene diene monomer (EPDM) based polymer composite. EPDM composites were successfully prepared using two roll‐mill and vulcanized in a hot press compression mold. Surface morphology indicates uniform dispersion of filler at lower filler loading, whereas at higher loading cluster/agglomeration was observed. 30 phr magnesium hydroxide (Mg(OH)2) loaded sample showed the highest static contact angle of 102.3°. Mg(OH)2 based samples show higher tensile strength because of strong interfacial interaction between filler and polymer. In addition, alumina trihydrate (ATH) and Mg(OH)2 based composite exhibit high thermal stability with initial thermal degradation temperature of ~200 and ~320°C, respectively. FTIR spectrum reveals the formation of strong –OH bonds between Mg(OH)2 and polymer molecules. A maximum enhancement in dielectric breakdown strength of ~50% and ~30% were recorded for 60 phr ATH and 30 phr Mg(OH)2 loaded EPDM composites respectively. Finally, the results indicate a strong possibility of developing EPDM based polymer composites as an efficient high voltage insulator.

A superhydrophobic anticorrosion silicone coating for covering cell body, joints and seawater storage in hydrogen production plants

Seawater electrolysis is one of the cost-effective techniques for producing hydrogen. To reduce the initial cost of hydrogen production plants, it is necessary to employ appropriate materials for electrodes, seawater storage, joints, and cell body. We recommend using A516 steel for seawater storage, and cell body. A516 steel is a medium-carbon steel with high strength and wear resistance, easy to work with, 6 times cheaper than stainless steel 316, and is widely used in oil and gas industry. However, it is prone to corrosion. For that, we developed an anticorrosion coating with high thermal and mechanical stress tolerance. The proposed coating is a room-temperature-vulcanizing (RTV) silicone mixed additives, adhesion promoter and fillers. The utilized adhesion promoter enhanced the adhesion by 5-fold, aluminum trihydrate (ATH) decreased the burning distance from 17 mm to 3 mm, and nanoparticles increased the contact angle to more than 160° and contact angle hysteresis less than 3°. The formulated superhydrophobic coating decreased the corrosion rate of A516 steel by 1673-fold from 200 mm/year to 0.12 mm/year.

Synergistic effect of aluminum trihydrate and zirconium hydroxide nanoparticles on mechanical properties, flammability, and thermal degradation of polyester/jute fiber composite

Synergistic effect of aluminum trihydrate and zirconium hydroxide nanoparticles on mechanical properties, flammability, and thermal degradation of polyester/jute fiber composite

Study of the influece of flame retardant additives on ultra-violet curing thermosetting composites

Fibre-reinforced polymer composites are materials capable of reducing weight while maintaining optimised properties in multiple applications. However, the use of composite materials is not suitable for all sectors, where the need for improved fire properties is highlighted. In the present study, a thermosetting matrix composed of UV-curable acrylic monomers and UV-transparent aluminium trihydrate (ATH) flame retardant fillers have been added to UV-transparent polyester resin for the manufacture of flame retardant composites. An in-depth study of the most suitable types of ATH-based flame retardant additives and possible synergistic combinations to improve the fire performance of the UV-curable composite has been carried out. Not only has the type of flame retardant been studied, but also the most suitable additive percentage to comply with railway sector regulations. The compatibility between the fillers and the matrix has been analysed by means of dielectric analysis, as well as the properties of the matrix and final composites against fire and mechanical properties.

On the icephobicity of damage-tolerant superhydrophobic bulk nanocomposites.

To address the increase in demand for superhydrophobic and icephobic surfaces with greater mechanical robustness, we fabricated damage-tolerant, abrasion-insensitive, and icephobic superhydrophobic bulk nanocomposites using a facile, cost-effective, industrially applicable, and environmentally benign strategy. We prepared nanocomposites composed of high-temperature vulcanized silicone rubber through the highly controlled incorporation of nanosized fumed silica and microsized aluminum trihydrate particles. The produced nanocomposites did not require additional processing, such as sand abrasion or plasma treatment, to acquire their superhydrophobic properties. The extended roughness throughout the whole bulk of the nanocomposites imparted the volumetric superhydrophobicity and resistance to mechanical damage. The presence of micro-nanoparticles also enhanced the thermal stability and icephobic properties of the silicone rubber. The icephobic behavior of the developed nanocomposites was assessed based on freezing delay and push-off tests both of which denoted improved icephobic properties, i.e., high freezing delay time and low ice adhesion strength. We verified the extended duration of superhydrophobicity within the bulk nanocomposite using sandpaper abrasion, severe cutter scratching, tape peeling, and water-jet impacts. This study represents the first evaluation, to the best of our knowledge, of the icephobic properties of both the surface and bulk of the produced nanocomposite subjected to several cycles of sandpaper abrasion. Interestingly, even after multiple abrasion cycles, the samples demonstrated considerably low ice adhesion strength confirming their bulk icephobicity. In a nutshell, our findings are very promising for the fabrication of mechanically robust icephobic materials.

Experimental evaluation of tri‐hydrated aluminium in fire‐retardant properties of glass fibre reinforced polymers

SummaryThis paper presents an experimental investigation of alumina trihydrate (ATH) in glass fibre reinforced polymers (GFRP), aiming to determine the influence of ATH concentration on improved flame‐retardant properties. For this research, different concentrations of ATH: 37 phr (parts per hundred resin), 40, 47.5, 50 and 55 phr, were added in isophthalic polyester matrix composites reinforced with E‐glass fibre through a pultrusion process. These composites were tested for flammability and flame propagation using the mass loss calorimeter cone (MLCC), limiting oxygen index (LOI) and glow wire tests. Simultaneous thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) was performed to evaluate the thermal stability and enthalpy. These analyses assessed the effectiveness and influence of each ATH concentration. It was observed in the MLCC tests that the ATH concentration of 40 phr reduced the peak heat release rate (PHRR) by 27% compared to a composite with 37 phr. All specimens showed the desired commercial result for wires and cables in the glow wire test since the composites reached the maximum glow wire flammability index (GWFI) of 960 °C and a glow wire ignition temperature (GWIT) above 900 °C. Thus, the addition of ATH above 40 phr leads to an improvement in the flame‐retardant properties of glass fibre reinforced polymers.

Synergistic effect of additives on electrical resistivity, fire and smoke suppression of silicone rubber for high voltage insulation

This paper reports the fire and smoke behaviour along with the DC electrical volume resistivity of silicone rubber filled with alumina trihydrate (ATH), milled glass fibre rods (GFRs) and graphene nanosheets (GNs). Results show that there is a significant de-escalation in the fire and smoke parameters of filled composites. As seen in SRE, adding a small amount (1 wt%) of GNs in PDMS filled with 30 wt%-ATH and 5 wt%-GFRs can remarkably reduce the THR to 38.36 MJ/m2 from 58.83 MJ/m2 in SRA and 47.24 MJ/m2 in SRB. Moreover, TSR is declined to 332.74 m2/m2 in SRE whilst it is measured at 1301.29 m2/m2 and 864.32 m2/m2 in SRA and SRB, respectively. Besides, it is noticed that the inner layer of char residue in filled composites is found significantly rigid and compact which provides a shielding effect against heat transfer. Moreover, DC volume resistivity of silicone rubber is improved with ATH and GFRs additives, but it tends to reduce with GNs. A reduction in volume resistivity is measured about −1.5%, −4.5% and −21% in SRD, SRE and SRF as compared to SRA. SRE is found to be the most promising filled silicone rubber composite with excellent fire retardancy and superb electrical volume resistivity which makes it suitable for electrical insulation applications.

Combined effect of multiwalled carbon nanotubes, graphene nanoplatelets, and aluminum trihydride on the thermal stability of epoxy composites

AbstractGlass fiber reinforced epoxy matrix is modified with a hybrid combination of fillers, and composites were fabricated using the advanced pultrusion technique. The focus of the investigation was to comprehensively understand the synergy between the carbon nanofillers and the role of aluminum trihydride on the thermal characteristics. A ratio of 2 wt% of multiwalled carbon nanotubes and 3 wt% of graphene is established by prior optimization technique for improved thermal properties. Using X‐ray diffraction analysis, the presence of the two carbon fillers was confirmed. Aluminum trihydrate was incorporated in the epoxy matrix with the objective of improving the thermal properties. By thermogravimetric analysis and differential scanning calorimetry, assessment of the thermal properties of the composites has been undertaken. The use of the two carbon fillers leads to enhancement of the thermal properties and contrary to expectations, the composites with hybrid fillers undergo minimal degradation due to pyrolysis. Uniform dispersion of the nanoparticles and good interfacial bonding of fillers with the epoxy are observed to be critical for the enhancement of thermal properties. The ratio of the two carbon fillers used helps in their preferential alignment and hence significant improvements in thermal properties are observed. Glass transition temperature reveals a 13°C increase increases due to the inclusion of carbon nanofillers and aluminum trihydride.