Synthetic Foam Research Articles

Izdelava velikih glivnih biokompozitov z nizko gostoto

As the need for a circular economy grows, so does the need for new sustainable materials. Biocomposites made from fungi are a sustainable alternative to synthetic foams. The key to commercializing this technology is knowing how to produce large quantities of such materials with the appropriate properties. As part of our experimental work, we have produced a larger mycelium biocomposite with a low density, a volume of 47 litres and a length of two metres. The final fungal biocomposite was produced by growing the mycelium in three stages; first in culture bags, then in two larger moulds, which were combined in a third stage. We used a culture of Ganoderma resinaceum and a specially formulated substrate to achieve a low density. The final biocomposite with a density of 80 kg/m³ met the target dimensions, remained infection-free and withstood lighter loads. The main disadvantage of the material was the small surface indentations caused by air inclusions in the substrate when the mycelium-laden substrate was transferred to the moulds.

Integrating vision-based AI and large language models for real-time water pollution surveillance.

Water pollution has become a major concern in recent years, affecting over 2 billion people worldwide, according to UNESCO. This pollution can occur by either naturally, such as algal blooms, or man-made when toxic substances are released into water bodies like lakes, rivers, springs, and oceans. To address this issue and monitor surface-level water pollution in local water bodies, an informative real-time vision-based surveillance system has been developed in conjunction with large language models (LLMs). This system has an integrated camera connected to a Raspberry Pi for processing input frames and is further linked to LLMs for generating contextual information regarding the type, causes, and impact of pollutants on both human health and the environment. This multi-model setup enables local authorities to monitor water pollution and take necessary steps to mitigate it. To train the vision model, seven major types of pollutants found in water bodies like algal bloom, synthetic foams, dead fishes, oil spills, wooden logs, industrial waste run-offs, and trashes were used for achieving accurate detection. ChatGPT API has been integrated with the model to generate contextual information about pollution detected. Thus, the multi-model system can conduct surveillance over water bodies and autonomously alert local authorities to take immediate action, eliminating the need for human intervention. PRACTITIONER POINTS: Combines cameras and LLMs with Raspberry Pi for processing and generating pollutant information. Uses YOLOv5 to detect algal blooms, synthetic foams, dead fish, oil spills, and industrial waste. Supports various modules and environments, including drones and mobile apps for broad monitoring. Educates on environmental healthand alerts authorities about waterpollution.

Betulin Enables Multifunctional Cellulose-Based Insulative Foams with Low Environmental Impacts.

The significance of synthetic foams as insulative materials stems from their mechanical and water resistance as well as their cost-effectiveness. Broadly, the design of building envelopes should also consider fire and mold resistance and the impacts on the environment (end of life and compostability). This study addresses these issues considering the ever-increasing demand for sustainable sources to develop highly porous insulative materials. We introduce a versatile strategy based on wet-foam laying of cellulosic fibers that leads to hierarchical structures whose performance is tailored by the surface incorporation of betulin (BT), a bioactive molecule extracted from tree bark, combined with poly(dimethylsiloxane) (PDMS) after installation of urethane linkages. As such, we introduce an eco-friendly alternative to traditional polyurethane foams with competitive mechanical and thermal insulation performance. The modification of the fiber foams at low BT loading simultaneously endows superhydrophobicity (water contact angle >150°), fire retardancy (self-extinguish within 10 s), microbial resistance, and durability (no degradation in soil conditions after 3 months). BT plays a critical role as an antimicrobial and hydrophobic agent that synergizes with PDMS to achieve fire resistance. The life cycle assessment of the BT-modified foams reveals a significant reduction in greenhouse gas emission and human toxicity compared with rigid polyurethane foams by 96 and 92%, respectively. Overall, the valorization of the bark-derived BT is demonstrated by considering the scalability and cost-effectiveness of solid foams designed to substitute petroleum-derived counterparts.

Fungal mycelium-based biofoam composite: A review in growth, properties and application

Recent years have shown a surge in interest in incorporating living systems into materials research to synthesize functional materials using biological resources. Among these, mycelium-based materials, notably biofoam, have emerged as innovative solutions for repurposing organic wastes that were previously considered unusable. The growth of mycelium, vital for the synthesis of biofoam, is influenced by a multuple of factors including substrate composition, moisture content, temperature, nutrient availability, pH levels, oxygen concentration, and measures for contamination control. Additionally, physical stimulation techniques have been explored to enhance mycelium growth, ranging from cold stress-induced adaptations to electrical shock-induced modifications and optimization of sound treatments and light exposure. This review highlights the growing interest in biofoam composite materials, a novel class of environmentally friendly and cost-effective materials that are gaining popularity, for advancing sustainable construction practices. Biofoam composites use organic fungal growth as a low-energy bio-fabrication process to transform abundant agricultural byproducts and waste into viable alternatives to energy-intensive manufactured building materials. Their versatility in composition and manufacturing methods allows them to be used in a wide range of applications, including insulation and door cores, panelling, flooring, and furniture components. Notably, biofoams outperform synthetic foams and engineered wood in terms of thermal insulation, sound absorption, and fire resistance, making them highly promising for construction industry. Besides, due to its customizable composition and production method, biofoam can be used in the replacement of foams, leather, wood, and plastics in a variety of applications such as water treatment and filtration, medical supplies and healthcare applications. However, despite their remarkable properties, biofoam typically serve as non- or semi-structural supplements to traditional construction materials due to inherent limitations. Nevertheless, the useful material properties of these materials, combined with their low cost, ease of manufacture, and environmental sustainability, imply that they will have an important part to play in the development of environmentally friendly materials in the future.

Pathways to formulate lightweight and ultra-lightweight 3D printable cementitious composites

This paper studies the pathways to formulate lightweight and ultra-lightweight 3D printable cementitious composites. A hybrid approach was proposed by combining the advantages of traditional chemical-induced foaming (foaming approach) and lightweight particulate inclusions (synthetic foam approach). A comprehensive experimental program was conducted to evaluate the effects of foaming agents and fly ash cenosphere (FAC) on the printability, microstructure, mechanical and thermal properties of 3D printed samples. The results showed that the hybrid approach could produce a mixture with a density as low as 470 kg/m3 while ensuring good flowability and buildability owing to the lubricating effect of foaming and supporting skeleton formed by FAC. In addition, a three-step homogenization procedure was also developed to predict the effective elastic modulus and thermal conductivity of 3D printable cementitious composites and cementitious foam. The findings of the study highlighted the effectiveness of the hybrid approach in formulating 3D printable ultra-lightweight cementitious composites in thermal insulation and acoustic applications.

Sustainable Innovation: Fabrication and Characterization of Mycelium-Based Green Composites for Modern Interior Materials Using Agro-Industrial Wastes and Different Species of Fungi.

Mycelium-based bio-composites (MBCs) represent a sustainable and innovative material with high potential for contemporary applications, particularly in the field of modern interior design. This research investigates the fabrication of MBCs for modern interior materials using agro-industrial wastes (bamboo sawdust and corn pericarp) and different fungal species. The study focuses on determining physical properties, including moisture content, shrinkage, density, water absorption, volumetric swelling, thermal degradation, and mechanical properties (bending, compression, impact, and tensile strength). The results indicate variations in moisture content and shrinkage based on fungal species and substrate types, with bamboo sawdust exhibiting lower shrinkage. The obtained density values range from 212.31 to 282.09 kg/m3, comparable to traditional materials, suggesting MBCs potential in diverse fields, especially as modern interior elements. Water absorption and volumetric swelling demonstrate the influence of substrate and fungal species, although they do not significantly impact the characteristics of interior decoration materials. Thermal degradation analysis aligns with established patterns, showcasing the suitability of MBCs for various applications. Scanning electron microscope observations reveal the morphological features of MBCs, emphasizing the role of fungal mycelia in binding substrate particles. Mechanical properties exhibit variations in bending, compression, impact, and tensile strength, with MBCs demonstrating compatibility with traditional materials used in interior elements. Those produced from L. sajor-caju and G. fornicatum show especially promising characteristics in this context. Particularly noteworthy are their superior compression and impact strength, surpassing values observed in certain synthetic foams multiple times. Moreover, this study reveals the biodegradability of MBCs, reaching standards for environmentally friendly materials. A comprehensive comparison with traditional materials further supports the potential of MBCs in sustainable material. Challenges in standardization, production scalability, and market adoption are identified, emphasizing the need for ongoing research, material engineering advancements, and biotechnological innovations. These efforts aim to enhance MBC properties, promoting sustainability in modern interior applications, while also facilitating their expansion into mass production within the innovative construction materials market.

Proof-of-Concept Study on the Feasibility of Supercritical Carbon Dioxide-Assisted Consolidation Treatment for a Pair of Goalkeeper Gloves on Synthetic Latex-Based Foam Mock-Ups

This work investigates the suitability of supercritical fluid technology for designing a safe, efficient and sustainable consolidation treatment for a pair of heavily degraded goalkeeper gloves. Traditional methods have revealed themselves as unsafe and inefficient, leading to material loss and a minimal enhancement of surface cohesion. To overcome these limitations, the use of supercritical carbon dioxide (scCO2) was explored in a treatment, where scCO2 behaves as a green solvent and consolidant carrier. In-depth and homogeneous application of the consolidant, without the need for direct contact with the foam material, was sought. As a proof of concept, the procedure was tested on samples that mimic the synthetic latex-based foam composition and condition of the object. Poly(vinyl acetate) was selected as a consolidant because its behaviour and solubility in scCO2 are known. Several experimental conditions were explored to assess the impact and feasibility of the scCO2-assisted consolidation procedure. Empirical observations, optical microscopy, scanning electron microscopy and infrared spectroscopy were used to monitor potential modifications in the samples and assess the treatment efficacy. The results highlighted the advantages and pitfalls of scCO2-assisted consolidation, paving the way for fine-tuning the process. It neither damaged the fragile surfaces of the foam samples nor increased material loss, which is an advantage compared to traditional treatments. The performed analysis suggested that homogeneous impregnation of the foams was achieved. This study might be a turning point in the conservation of foam-based museum objects, as the results indicate the suitability of the scCO2-assisted consolidation process as a non-toxic and more efficient alternative, being safer for the object.

Innovative strategy for controlling resonant frequencies of syntactic polymer foams regulating by hollow microspheres

This study aims to precisely control the resonant frequency of synthetic composite foam materials with fixed dimensions. By incorporating rigid hollow glass microspheres XLD3000(XLD) and flexible hollow polymer microspheres MFL-81GCA(MFL) into the base resin (EP), we prepared synthetic composite foams containing different volume fractions of hollow microspheres (EP-XLD and EP-MFL). We conducted tests and analyses on the density, mechanical properties, resonant frequency, and microstructure of the EP-XLD and EP-MFL systems. Results indicate that as the volume fraction of hollow microspheres increases, the flexural specific modulus of the EP-XLD and EP-MFL systems, respectively, exhibits a linear increase and decrease, and the resonant frequency shifts linearly towards higher and lower frequencies. This trend aligns with theoretical predictions, affirming that the material’s resonant frequency is closely related to its flexural modulus. This research not only deepens the understanding of the control mechanisms for the resonant frequency of synthetic composite foams but also proposes an innovative material design strategy with broad application potential, particularly in the fields of acoustics, damping, and structural materials, where it promises to significantly enhance material performance and meet specific engineering needs.

Assessment of the tolerance angle for pedicle screw insertion.

Cannulation process intervenes before implantation of pedicle screw and depends on the surgeon's experience. A reliable experimental protocol has been developed for the characterization of the slipping behavior of the surgical tool on the cortical shell simulated by synthetic materials. Three types of synthetic foam samples with three different densities were tested using an MTS Acumen 3 A/T electrodynamic device with a tri-axis 3 kN Kistler load cell mounted on a surgical tool, moving at a constant rotational speed of 10° mm-1 and performing a three-step cannulation test. Cannulation angle varied between 10° and 30°. Synthetic samples were scanned after each tests, and cannulation coefficient associated to each perforation section was computed. Reproducibility tests resulted in an ICC for Sawbone samples of 0.979 (p < 0.001) and of 0.909 (p < 0.001) for Creaplast and Sawbone samples. Cannulation coefficient and maximum force in Z-axis are found the best descriptors of the perforation. Angular threshold for perforation prediction was found to be 17.5° with an area under the curve of the Receiver Operating Characteristic of 89.5%. This protocol characterizes the cannulation process before pedicle screw insertion and identifies the perforation tool angle until which the surgical tool slips on the cortical shell depending on bone quality.

Castor-oil biobased foam: the effect of the composition on the physical and mechanical properties via a statistical mixture design.

PU foams are versatile materials that find applications in a wide range of products, from upholstery to packaging and construction. These foams consist primarily of two components, polyol and prepolymer, and their concentrations play a crucial role in determining their physical and mechanical properties. A second-order mixture design approach is used in this work to identify the significant components and their contributions on the physical-mechanical properties of biodegradable castor oil-based foams. The experimental design includes three components: two types of polyols and one prepolymer. These components are varied in nine distinct conditions to evaluate their effects on properties such as expansion rate, bulk density, compressive strength, and tensile strength. The Scheffé's quadratic model coefficients exhibit R-squared values higher than 0.84 in most cases. Chemical analysis using infrared spectroscopy confirms the successful formation of the urethane bond during the manufacturing process. The biobased foams developed in this work have densities ranging between 61 and 100 kg m-3, compressive modulus of 11-15 MPa and compressive strength between 273 and 429 kPa. The tensile modulus varies between 3.2 and 4.9 MPa, with a tensile strength in the range of 370-500 kPa. These results highlight the potential of biodegradable castor oil-based foams as promising alternative materials to traditional synthetic foams.

Preparation and characterization of potato crust-based polyurethane foam-I

Polyurethanes (PUs) are polymers obtained by reacting diisocyanates with a group of polyols. The first synthesized PU compounds were prepared using petroleum subproduct compounds. In this research study, biomass-containing polyols, which have been studied by other scientists, were prepared using potato crust and polymerized with diisocyanates to produce PU foam. Polyol reactions were carried out using the microwave heating method. Synthesis reactions and structural properties of polyols have been studied in many aspects. The most available polyol was used for PU synthesis. Different formulations were tried for PU synthesis and as a result, PU foam containing nearly 25% starch-polyol was synthesized. The chemical structure of PU polymer was identified by ATR-FTIR spectroscopy and crystallographic properties by WA-XRD analysis. The physical and mechanical properties of PU foam, which is used as a large number of building and construction materials, including thermal insulation materials, were evaluated by comparing them with a commercial PU foam. According to the results of our research, it was detected that the incorporation of biomass into the structure of PU polymer improved its density, heat conduction coefficient, pressure based mechanical properties. PU foam derived from potato waste has a WA XRD-ray diffraction peak between 13.1-28.5o. This data is between 12.5-23o in synthetic commercial foam and has been positively improved in the product we synthesized as a result of combining biomass into the structure. The synthesized biomass-based PU foam can be used as thermal insulation material. Biomass-based PU foam has been synthesized with features that can be used as a thermal insulation material.

Biomechanical comparison of headless compression screws versus independent locking screw for intra-articular fractures

PurposeHeadless compression screws (HCS) have a variable thread pitch and headless design enabling them to embed below the articular surface and generate compression force for fracture healing without restricting movement. Locking screws have greater variety of dimensions and a threaded pitch mirroring the design of the HCS. The objective of this study is to determine whether locking screws can generate compression force and compare the compressive forces generated by HCS versus locking screws.MethodA comparison between 3.5-mm HCS versus 3.5-mm locking screws and 2.8-mm HCS versus 2.7-mm locking screws was performed using a synthetic foam bone model (Synbone) and FlexiForce sensors to record the compression forces (N). The mean peak compression force was calculated from a sample of 3 screws for each screw type. Statistical analysis was performed using the one-way ANOVA test and statistical significance was determined to be p = < 0.05.ResultsThe 3.5-mm Synthes and Smith and Nephew locking screws generated similar peak compression forces to the 3.5-mm Acutrak 2 headless compression screws with no statistically significant difference between them. The smaller 2.7-mm Synthes and Smith and Nephew locking screws initially generated similar compressive forces up to 1.5 and 2 revolutions, respectively, but their peak compression force was less compared to the 2.8-mm Micro Acutrak 2 HCS.ConclusionLocking screws are able to generate compressive forces and may be a viable alternative to headless compressive screws supporting their use for intra-articular fractures.

Influence of Relative Humidity on Electrical Properties of Textile Laminates

The aim of this paper is to determine the influence of relative humidity on the comfort and electrical resistance properties of textile laminates in order to predict possible changes in footwear protection levels. Four textile laminates of different structure and fibre nature were selected for the study. It was determined that water vapour absorption of textile laminates strongly depends on the humidity of the storage environment. The absorption ability of laminates increases about 1.8 – 3 times as relative humidity increases from 65 % up to 95 %. The degree of increase depends on the textile laminate structure and the nature of the materials layers. The electrical properties of protective footwear can be influenced by the structure, thickness, relative humidity, and voltage of textile laminates. For textile laminates composed of natural and synthetic fibres and polymer foam as insulators, the resistivity increases with the thickness of the synthetic fibre and polymer layer. At low voltage (U = 100 V), the textile laminates tested became insulating materials, as the electrical resistivity exceeded the threshold values for antistatic materials in all relative humidity ranges. At high voltage (U = 500 V) the electrical resistivity of textile the laminates drops dramatically when the relative air humidity increases and the level of protection of the laminates depend on the amount of moisture absorbed and the nature of the layer materials. The laminates possessed insulating properties in environments of up to 65 % relative humidity. In a high humidity of the environment, the insulating properties of textile laminates turned to antistatic, except for laminate without a polymeric membrane, which became conductive.

Sliding on cortical shell: Biomechanical characterization of the vertebral cannulation for pedicle screw insertion

BackgroundPedicular screws pull-out has been well studied unlike their insertion. A need for characterizing cannulation before pedicle screw implantation is highlighted in literature and offers promising prospects for future intra-operation instrumentation. A reliable cannulation protocol for ex-vivo testing in swine and cadaver vertebrae is presented in this work to predict extra pedicular perforation. MethodsAn MTS Acumen 3 A/T electrodynamic device, with a tri-axis 3 kN Kistler load cell mounted on a surgical tool was used to reproduce surgeon's gesture by moving at a constant rotational speed of 10°/mm and performing a three-section test. Perforation of the pedicle's cortical shell was planned through a design of experiment on the surgical tool angle at the entry point. Samples were scanned before and after mechanical tests and reproducibility of the protocol was tested on synthetic foam. Computation of the angle between cannulation tool and pedicle cortical shell was performed as well as cannulation coefficient of each perforation section. FindingsA total of 68 pedicles were tested: 19 perforated and 21 non-perforated human pedicles, 17 perforated and 16 non-perforated swine pedicles. The reproducibility of the protocol for cannulation coefficient computation resulted in an intraclass correlation coefficient of 0.979. Cannulation coefficients results presented variability within spinal levels as well as between swine and human model. Correlation between bone density and cannulation coefficient was found significant (p < 0.005). Torque measurement was found to be the best predictor of perforation. Threshold of angle for prediction of perforation was found to be 21.7°. InterpretationCharacterizing pedicle cannulation enables to predict extra pedicular perforation. Influence of bone mineral density and patient-specific morphology on pedicle cannulation has been highlighted together with a comparison of swine and cadaver models.

Toxicological and hygienic assessment of modern thermo-insulating polymer materials during thermal exposure

Introduction. Polyethylene and synthetic foam caoutchouc are used for thermal insulation of communications, at temperatures not exceeding 90 °C and 105 °C, respectively. Data on how these materials will behave in the appropriate temperature conditions was not be found. &#x0D; The purpose of the study was to conduct a toxicological and hygienic assessment of products made of polyethylene foam and synthetic foam rubber under thermal exposure.&#x0D; Materials and methods. The thermal effect on the studied samples was modelled in a climate chamber. The time interval during the mass loss of the samples was determined, a sanitary and chemical study of the gas-air mixture in the climatic chamber was carried out. To conduct a toxicological and hygienic study in animals, a swim-escape conditioned active avoidance response was developed.&#x0D; Results. Under thermal (90 °C) exposure for 72 hours to polyethylene tube, a loss of 0.77% of the initial mass of the sample occurs. Thermal exposure (105 °C) to synthetic foam caoutchouc resulted in a loss of 15.3% of the initial mass of the sample for 108 hours, while pronounced changes in the appearance of the samples were determined. When conducting a sanitary and chemical study in the climate chamber, an increase in the concentration of carbon monoxide was determined after 12, 24, and 72 hours and hydrogen chloride after 12 and 24 hours following the onset of thermal exposure compared with the values of their average daily maximum permissible concentration. Thermal exposure to the sample and synthetic foam caoutchouc led to an increase in the concentration of ammonia, carbon monoxide and hydrogen chloride 12 and 24 hours after the start of exposure compared with the average daily maximum permissible concentration. During the toxicological and hygienic study, animals exposed to thermal degradation products of the materials under study were revealed to show learning disabilities.&#x0D; Limitations. They are conditioned by the methodology of the study. A quantitative analysis of some gaseous thermal degradation products released into the climate chamber was performed, without taking into account the aerosols formed.&#x0D; Conclusion. Thermal insulation materials made of synthetic foam rubber and polyethylene foam lose their structural properties when they are operated in the maximum permissible temperature conditions (105 °C and 90 °C, respectively). When they are used in appropriate temperature conditions, the formation of toxic products occurs, the inhalation effect of which leads to a disturbances of the learning ability in laboratory animals.

STUDY OF THE METHOD OF DRILLING WASTE WATER TREATMENT FROM MECHANICAL IMPURITIES BY SEDIMENTATION AND FILTRATION

The problem of treatment of drilling wastewater from mechanical impurities and its reuse for technological process is unresolved. The study summarizes results of researches in drilling wastewater treatment methods. It is relevant for areas of extraction of hydrocarbon raw materials. The authors suggest applying a scheme of treating drilling wastewater from mechanical impurities consisting of two stages of purification – sedimentation and filtration through various materials for loading filters: sawdust, peat, soil (medium loam), ash, starch, household dust (a mixture microorganisms), charcoal, gauze, polyester wadding (lighat, voluminous, elastic nonwoven fabric), foam rubber (soft cellular synthetic foam with high elasticity and breathability). Soil, ash, starch, peat and coal were cleaned from impurities and ground to a fine state. Eleven individual materials and their various combinations were studied as filter loads. The tests were replicated three times. Untreated drilling wastewater served as a control background sample for calculating efficiency. The possibility of wastewater treatment by sedimentation and subsequent filtration using industrial waste as a loading material for filter was researched. It was found out that treatment efficiency increases when wastes used in filters are grinded to microparticles.

Effects of accelerated aging on compressive response of natural and synthetic core materials: freeze-thaw cycles and UV radiation

ABSTRACT The great efforts to reduce the environmental impact of composite materials by replacing synthetic components with bio-based ones are involving also sandwich structures. Agglomerated cork proved to be a feasible alternative to traditional polymeric foam as core material. Sandwich structures are extremely prone to impact events which can cause the direct exposure of the core material to the external environment making fundamental to know how its out-of-plane properties can be influenced by external factors such as sunlight and rain. The present work assessed the effects of UV accelerated aging and freeze–thaw (FT) cycles on the compressive behavior of two agglomerated corks with different densities providing also a direct comparison with a traditional PVC foam. Agglomerated cork compressive properties increase when exposed to UV accelerated aging up to 600 h, determining an increase of 31 % and 9 % in the compressive modulus for the less dense and denser cork, respectively. No significant changes were observed for the synthetic foam. FT cycles on as-received specimens induce a decrease in cores compressive properties after 30-day cycling, with a reduction in compressive modulus of approximately 11 % for PVC foam and of 12 % and 11 % for the less dense and denser cork, respectively.

The Thermal and Mechanical Behaviour of Wood-PLA Composites Processed by Additive Manufacturing for Building Insulation.

This study was aimed at considering the potential of wood-based composites processed using additive manufacturing as insulators in the building sector. A polylactic acid blend with 30% wood particles was used as a feedstock material in fused filament technology. Its thermal and mechanical properties were determined for various processing conditions, including printing temperature and infill rate. The results showed a minor contraction in its tensile performance as a result of the printing process. The printing temperature had a negligible effect on its stiffness and a limited influence on the other engineering constants, such as the tensile strength and ultimate stress. The thermal properties of printed structures have been found to significantly depend on the infill rate. Although the tested 3D printed wood-PLA material exhibited good thermal properties, which were tuneable using the printing conditions, its performance was still 38% to 57% lower compared to insulators such as the glass wool of the synthetic foams used in the building sector.

Influence of hybridizing fillers on mechanical properties of foam composite panel

AbstractFoam composite panels made from hybrid fillers are materials developed to have low density with high mechanical properties. This work focuses on improving the mechanical properties of epoxy‐based foam composite panels with hybridized fillers by combining hollow glass microspheres (HGM) and nanoclay. The HGM content was varied from 1 wt.% to 3 wt.% in foam composites panel, while nanoclay content was varied from 1 wt.% to 5 wt.% in each of the HGM‐filled series of foam composites panel, these foam composite panels were fabricated using a conventional resin casting method. The mechanical properties such as tensile strength, impact strength, hardness, flexural strength of the prepared hybrid‐filled foam composite panels were determined and compared with the neat epoxy. It was found that the hybrid‐filled foam composite panels exhibited improved mechanical properties than the neat epoxy. These improved properties were because of excellent interfacial adhesion between the hybrid fillers and the matrix. The improved mechanical properties could suggest that this material may be suitable for application in industries where lightweight materials with good mechanical properties are required. This study showed a new area of synthetic foam development research by enhancing mechanical properties using hybrid‐filled.

Hollow glass microspheres/phenolic syntactic foams with excellent mechanical and thermal insulate performance.

Syntactic foams with low density as well as low thermal conduction and proper mechanical performance are vitally important for aerospace, marine, and automotive industries. Here, phenolic-based syntactic foams were fabricated by combining the hollow glass microsphere (GMs) with phenolic resin of in situ synthesis. Benefited from the stirring and hot-pressing treatment, microspheres dispersed homogeneously in the resin matrix and it greatly reduced the density of the composites. Stretching and compression tests were performed to investigate the mechanical behavior of the foams. It is found that both the compressive and tensile strength decreased as the filler loadings increasing. While the elasticity modulus was improved. On the other hand, thermal properties tests revealed superior thermal stability and thermal insulate performance of the composites. The final residue content of the synthetic foam with 40wt% filler was improved by ∼31.5% than that of the neat one at 700°C. And samples with 20wt% microspheres reached a minimum thermal conductivity value of approximately 0.129W (m·K)-1 which is ∼46.7% lower than that of neat resin [0.298W (m·K)-1]. This work provides a feasible strategy to construct syntactic foams with low density and ideal thermal properties.