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1
Walbrück, Katharina, Felicitas Maeting, Steffen Witzleben, and Dietmar Stephan. "Natural Fiber-Stabilized Geopolymer Foams—A Review." Materials 13, no. 14 (July 17, 2020): 3198. http://dx.doi.org/10.3390/ma13143198.
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The development of sustainable, environmentally friendly insulation materials with a reduced carbon footprint is attracting increased interest. One alternative to conventional insulation materials are foamed geopolymers. Similar to foamed concrete, the mechanical properties of geopolymer foams can also be improved by using fibers for reinforcement. This paper presents an overview of the latest research findings in the field of fiber-reinforced geopolymer foam concrete with special focus on natural fibers reinforcement. Furthermore, some basic and background information of natural fibers and geopolymer foams are reported. In most of the research, foams are produced either through chemical foaming with hydrogen peroxide or aluminum powder, or through mechanical foaming which includes a foaming agent. However, previous reviews have not sufficiently addresses the fabrication of geopolymer foams by syntactic foams. Finally, recent efforts to reduce the fiber degradation in geopolymer concrete are discussed along with challenges for natural fiber reinforced-geopolymer foam concrete.
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Bhaskar, Dr Kiran. "Foam Concrete: A Review." International Journal for Research in Applied Science and Engineering Technology 9, no. VII (July 25, 2021): 2224–34. http://dx.doi.org/10.22214/ijraset.2021.36866.
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Foam concrete has the potential of being an alternative to ordinary concrete, as it reduces dead loads on the structure and foundation, contributes to energy conservation, and lowers the cost of production and labour cost during the construction and transportation. Presently the emerging trend is the use of foam concrete, which is a lightweight concrete having more strength-to-weight ratio with density varying from 300 to 2000 kg/m3. This reduces the dead load on the structure, cost of production and labour cost involved during the construction and transportation. Also, the large number of pores in the foamed concrete reduces the thermal and sound absorption, thus making the structure appropriate for all climatic conditions. The paper outlines a review of foamed concrete in terms of its definitions & classifications, materials, mix design, production of foamed concrete, properties of foamed concrete such as workability, density, compressive strength, porosity, fire resistance, shrinkage, water absorption, permeability. Apart from this, the paper outlines various applications of foam concrete.
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Sri, Sunarjono, and Hartadi Sutanto Muslich. "Investigating Foamed Bitumen Viscosity." Applied Mechanics and Materials 660 (October 2014): 254–58. http://dx.doi.org/10.4028/www.scientific.net/amm.660.254.
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Foamed bitumen is a binder of cold mix road recycling materials. It is necessary to understand the best foamed bitumen properties prior to mixing with aggregate materials. Viscosity is one of the important properties, which facilitate the foam to distribute across the aggregate phase in the mixing process, and form a well coated asphalt mix. Unfortunately, the understanding of foamed bitumen viscosity and its contribution in the development of mixture performance is still poorly understood. This paper discusses foamed bitumen viscosity which was explored based on theoretical studies and a series of laboratory investigation. Foamed bitumen was produced using bitumen Pen 70/100 at temperature of 180°C. The research method was developed in three activities, i.e. (1) the previous studies on the foamed bitumen rheology, (2) investigating flow behavior of foamed bitumen, and (3) estimating foamed bitumen viscosity using Kraynik equation.The research results can be summarized in the following three points. First, foamed bitumen consists of gas content and liquid bitumen, in which the value of foam viscosity increases with the gas content. Second, foam flow can be used to indicate the apparent foam viscosity. Foamed bitumen with a higher foaming water content (FWC) tends to have a decreased flow rate and hence higher apparent viscosity. Third, foamed bitumen viscosity estimated using Kraynik equation is affected by gas content and liquid bitumen viscosity. It was found that an ERm of around 35 (or at FWC of 6%) is the critical area of foam viscosity.
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Calabrese, Luigi, Stefano De Antonellis, Salvatore Vasta, Vincenza Brancato, and Angelo Freni. "Modified Silicone-SAPO34 Composite Materials for Adsorption Thermal Energy Storage Systems." Applied Sciences 10, no. 23 (December 5, 2020): 8715. http://dx.doi.org/10.3390/app10238715.
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In this work, novel silicone-SAPO34 composite materials are proposed for application in adsorption thermal energy storage systems. The innovative composite materials were obtained through a mold foaming process activated by a dehydrogenative coupling reaction between properly selected siloxane compounds. Morphology analysis by optical microscopy and measurement of the mechanical properties of the foamed materials at varying zeolite content demonstrated a quite homogeneous open-cell structure and good structural stability of the foam. Water adsorption isotherms of the adsorbent foams expanded in free space and inside paperboard were measured by a gravimetric adsorption apparatus, demonstrating that the presence of the polymeric fraction does not affect the adsorption capacity of the SAPO34 fraction added in the composite foam. Finally, main adsorption and thermodynamic properties of the proposed foam have been compared with those of other adsorbent materials, confirming the possible use of these new composite foams as adsorbent materials for adsorption thermal energy storage systems.
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Li, Jian, Xun Zhang Yu, and Kai Zhang. "Absorptive and Biodegraded Polyurethane Foamed Urea." Advanced Materials Research 152-153 (October 2010): 131–35. http://dx.doi.org/10.4028/www.scientific.net/amr.152-153.131.
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In this article, konjac flour, super absorptive resin and pellet urea were added into flexible polyurethane foamed plastic with polyether polyol and isocyanate as the raw materials by a new water-foamed technology to manufacture a kind of absorptive and biodegraded polyurethane foamed fertilizer. Polyurethane foam was used as a carrier material and konjac flour was used as a biodegradable agent. The results showed that the slow-release velocity of urea could be controlled by regulating the densities of polyurethane foams, the content of konjac flour and super absorptive resin. The carrier material could be degraded konjac flour by naturally.
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Cao, Kai, De Ming Wang, and Xin Xiao Lu. "The New Fire Prevention Materials Using in the Coal Fire Zones-Foamed Gel." Advanced Materials Research 383-390 (November 2011): 2705–9. http://dx.doi.org/10.4028/www.scientific.net/amr.383-390.2705.
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Coal fires are emerging as a global threat with significant economic, social and ecological impacts, besides the loss of energy resources those fires cause air and water pollution and emit enormous amounts of green house gases (carbon dioxide and methane), how to prevent and extinct the fires has been a worldwide issue. According to the respective limitation and characteristic of gel fire prevention materials and foam fire prevention materials, a new thinking of foamed gel coal fire prevention materials is put forward creatively. Foamed gel that includes the characteristic of gel and foam possessed the property of accumulation. It also has the performance of sealing and secluding oxygen. This paper describes the composition and characteristic of foamed gel, as well as the laboratory production process. For large coal fire zones, the new fire prevention materials (Foamed Gel) have a broad application prospect.
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Liu, Baodong, Xinjie Huang, Shuo Wang, Dongmei Wang, and Hongge Guo. "Performance of Polyvinyl Alcohol/Bagasse Fibre Foamed Composites as Cushion Packaging Materials." Coatings 11, no. 9 (September 10, 2021): 1094. http://dx.doi.org/10.3390/coatings11091094.
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This work was designed to determine the mechanical properties and static cushioning performance of polyvinyl alcohol (PVA)/bagasse fibre foam composites with a multiple-factor experiment. Scanning electron microscopy (SEM) analysis and static cushioning tests were performed on the foamed composites and the results were compared with those of commonly used expanded polystyrene (EPS). The results were as follows: the materials had a mainly open cell structure, and bagasse fibre had good compatibility with PVA foam. With increasing PVA content, the mechanical properties of the system improved. The mechanical properties and static cushioning properties of the foam composite almost approached those of EPS. In addition, a small amount of sodium tetraborate obviously regulated the foaming ratio of foamed composites. With increasing sodium tetraborate content, the mechanical properties of foamed composites were enhanced. The yield strength and Young’s modulus of the material prepared by reducing the water content to 80.19 wt% were too high and not suitable for cushioned packaging of light and fragile products.
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Li, Mei Juan, Kun Xiang, Qiang Guo Luo, Qiang Shen, and Lian Meng Zhang. "Preparation and Density Control of PMMA Microcellular Foams via Supercritical Carbon Dioxide Foaming." Key Engineering Materials 616 (June 2014): 242–46. http://dx.doi.org/10.4028/www.scientific.net/kem.616.242.
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Microcellular polymeric foam is a new class of materials which has been widely used in many industries. The foaming of polymethyl metacrylate (PMMA) using supercritical carbon dioxide (ScCO2) which is inexpensive and environmental friendly has been studied to better understand the foaming process. The pieces of PMMA are put into a saturation vessel of which temperature and pressure are kept constant. Supercritical carbon dioxide (ScCO2) at temperature between 65 °C and 105 °C and pressure between 8 MPa and 16 MPa is used as a foaming agent. After saturation of carbon dioxide, rapid decompression of ScCO2 saturated PMMA yields expanded microcellular foams. The densities of foamed PMMA materials are tested by true density analyzer, while the microstructures of a variety of density foamed PMMA materials are characterized by scaning electron microscopy (SEM). The cell size and cell density are calculated via image analysis. The effect of the process condition on the cell morphologies and mass density of the foam is investigated by considering the solubility of carbon dioxide in PMMA. The relationship between the mass density of foamed PMMA (ρ) and foaming temperature (T) and pressure (P) are respectively certained quantificationally.
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Bledzki, A. K., M. Rohleder, H. Kirschling, and A. Chate. "Microcellular Polycarbonate with Improved Notched Impact Strength Produced by Injection Moulding with Physical Blowing Agent." Cellular Polymers 27, no. 6 (November 2008): 327–45. http://dx.doi.org/10.1177/026248930802700601.
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Polycarbonate has the reputation of having a tough breaking behaviour, but it is often unknown that this applies only to special conditions. The impact strength of polycarbonate depends on the temperature, the thickness (with a tough brittle transition at thickness increases), contribution of notch tip radius, impact speed, physical blowing agent, molecular weight of the polymer and the processing parameters. Research results indicated that microcellular foams produced by injection moulding with physical blowing agent (MuCell™ Technology by Trexel) shows significant higher notched impact strength than compact polycarbonate, if the compact material is brittle under the same test parameters. However, if the compact polycarbonate breaks toughly, the notched impact strength of the foamed material is always lower. Therefore, it is highly important to pay attention to the test parameters and conditions when comparing the toughness of the foamed with the compact material. The toughness of microcellular foams shows similar properties to PC/ABS and PC/PP blend systems, which provides the possibility to combine the higher impact strength with the advantages of microcellular foaming like weight reduction, lower shrinkage, shorter cycle times, lower clamp forces and reduced melt viscosity. In order to use technologies and conditions which are applied in the polymer industry, all materials were produced by an injection moulding process. Special processing technologies like gas counter pressure and precision mould opening were used in order to reach microcellular foam structures with cell diameters around 10 μm. These technologies yield exactly adjustable foam morphologies. Special morphologies are required to improve the notched impact strength of the foamed material. Two different equivalent models were extracted from the analyses, which indicate significant higher notched impact strength than the compact material under the same test conditions. The knowledge of the ideal foam morphologies enables the industry to produce foamed materials with improved mechanical properties.
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Pop-Iliev, Remon, and Chul B. Park. "Melt Compounding Based Rotational Foam Molding Technology for Manufacture of Polypropylene Foams." Journal of Reinforced Plastics and Composites 21, no. 2 (January 2002): 101–20. http://dx.doi.org/10.1177/0731684402021002285.
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This paper is intended to provide an engineering understanding of the technological potentials for processing polypropylene (PP) foams in rotational foam molding. A process proposal, based on the melt compounding material-preparation approach, capable of producing completely foamed, single-layer, single-piece PP products in rotational foam molding, is disclosed in detail. It comprises dispersing a chemical blowing agent (CBA) in the PP matrix using a twin-screw compounder, pelletizing the obtained expandable composition, and then producing foams in an uninterrupted rotational foam molding cycle by using the pre-compounded foamable pellets. Several PP grades were deliberately selected to cover a wide range of melt flow rates (MFR), starting from 5.5 up to 35 dg/min. After the raw materials participating in the study were characterized using thermal analysis instrumentation, different foamable compositions were formulated in order to prepare both 3-fold and 6-fold foamable pellets from each PP grade. The optimal foam processing strategies were identified via a systematic experimental parametric search. Foams with the best cell morphologies were obtained out of the high melt strength PP grades. In addition, the experimental results revealed that the cell morphology of the processed PP foams is not as good as that of respective PE foams. However, the cell morphologies of the PP foams processed by using the melt compounding-based approach demonstrated significant improvements in comparison with those processed by using the dry blending-based approach.
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Cherunova, I., N. Kornev, and Mathias Paschen. "Study of Compression Soft Porous Foam Materials." Solid State Phenomena 265 (September 2017): 279–83. http://dx.doi.org/10.4028/www.scientific.net/ssp.265.279.
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The paper presents the findings of the research into neoprene-like soft foamed materials during compression in water. The specific features of the internal structure of such materials lead to complex deformations. This is related to the specific features of the internal structure of materials that contain a large amount of inert air. The paper also presents the findings of structural studies which explained the relationship between the elastic properties of materials and the strength of polymer bonds forming internal air cavities. When foamed the polymer sections are destroyed under compression, it results in the loss of enclosed volume of air voids. This changes the total volume and thickness of the material, which defines some physical and thermal properties of products made of such material. Hydrostatic pressure environments have their own specific features. Rheological properties of soft polymers in a hydrostatic pressure environment give rise to a composite effect of compression deformation. The study of recent developments in the research into polymer deformations in a hydrostatic pressure environment shows that it is difficult to record the stages of reversible and nonreversible compression deformation in near-real experimental simulation of diving operations. The paper presents the developments and findings of experimental design studies for a product (wetsuit) made of foamed materials that were conducted in a hydrostatic pressure environment in an enclosed volume using special Drucktank equipment by the Marine Engineering Department of the University of Rostock
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Du, Chuan Wei, and Guo Zhong Li. "Study on Preparation of a New Foamed Cement Material." Advanced Materials Research 648 (January 2013): 104–7. http://dx.doi.org/10.4028/www.scientific.net/amr.648.104.
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The ordinary Portland cement as matrix materials and fly ash as a lightweight aggregate were used to prepare a new foamed cement material by chemical foaming method though adding a proper level of foaming agent, foam stabilizer, and glass fiber. The raw materials’ ratio of new foamed cement was determined through the experiment. The microstructure of bubble was analysed by electronic scanning electron microscopy. The mechanism of foam stabilizer and fiber reinforced mechanisms were explored.
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Costanza, Girolamo, and Maria Elisa Tata. "Parameters Affecting Energy Absorption in Metal Foams." Materials Science Forum 941 (December 2018): 1552–57. http://dx.doi.org/10.4028/www.scientific.net/msf.941.1552.
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Recent research findings on the mechanical behavior of metal foams are summarized in this work. Thanks to their properties in compressive tests, a wide range of foamed materials has been considered for energy-absorption applications such as Al, Fe, Ti, Ni and its alloys. The main parameters affecting energy absorption are focused and presented: cell size, relative density, strain rate, hybrid foam (Al-Cu, Al-Ni), base metal, and composites structures (Al-foam filled tube and sandwich). Metal foam response, impact resistance and failure are discussed in many configurations and test conditions. The results of finite elements modelling and its validation by means of mechanical tests are discussed too.
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Nuțescu Duduman, Catalina, Oana Bălţătescu, Ioan Carcea, Nicanor Cimpoeşu, Mihai Axinte, and Cristian Adoroaei. "Research on Obtaining Open-Cell Foam by Molten Metal Infiltration." Advanced Materials Research 1036 (October 2014): 46–51. http://dx.doi.org/10.4028/www.scientific.net/amr.1036.46.
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AbstractPorous metallic materials are the subject of numerous recent studies due to their ability to combine good mechanical and physical properties with low weight. Metal foams are an innovative and challenging class of materials. Due to their unusual physical, mechanical, thermal, and acoustic properties, they have been granted much attention by materials researchers in the last few years and are finding several structural and functional applications in different engineering fields. This foam was produced by a process, which consists mainly in infiltrating molten metal bed of silica gel particles. Later to use hydrofluoric acid (HF) as solvent. In this paper is presented obtaining of metal foam with open-cell. Microstructural analyses on foamed specimens showed uniform microstructure of ligaments and a very regular and well reproducible open-cell morphology. Compositional analyses on foamed specimens showed uniform microstructure of ligaments and the absence of SiO2 interaction with the metal reproducible open-cell morphology. The use of SiO2 beads as space holder results in cellular metals with a very homogeneous arrangement of almost spherical cavities. Additionally, because of the high chemical stability of SiO2, reactions between space holder and molten metal tend to be minimal or inexistent. This methodology is based on cheap commercial consumables and a simple technology, focusing on intermediate-density low-cost foams with interesting cost/benefits ratio. Keywordsinfiltrating molten metal, silica gel particles, microstructure of ligaments, microstructural analyses, open-cell morphology
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Kharbas, Hrishikesh A., Thomas Ellingham, Mihai Manitiu, Guenter Scholz, and Lih-Sheng Turng. "Effect of a cross-linking agent on the foamability of microcellular injection molded thermoplastic polyurethane." Journal of Cellular Plastics 53, no. 4 (June 7, 2016): 407–23. http://dx.doi.org/10.1177/0021955x16652109.
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Thermoplastic polyurethane is one of the most versatile thermoplastic materials being used in a myriad of industrial and commercial applications. Thermoplastic polyurethane foams are finding new applications in various industries including furniture, automotive, sportswear, and packaging because of their easy processability and desirable, customizable properties. Low bulk density and a good foam microstructure are important properties that affect the mechanical properties, economics, and performance of the final product. In this study, the effect of a cross-linking agent on the foamability of microcellular injection molded thermoplastic polyurethane was studied with an aim to reduce the bulk density while achieving a consistent microstructure. Gel permeation chromatography showed an increase in the weight average molecular weight by 5.0% with the addition of a cross-linking agent. Rheological studies on the materials showed that the addition of a cross-linking agent increased the storage modulus and viscosity, while reducing the tan δ value. Using microcellular injection molding, cross-linked thermoplastic polyurethane could be foamed to a minimum density of 0.159 g/cc at the higher end of the processing window, as compared with a minimum density of 0.193 g/cc for pure thermoplastic polyurethane foam. Scanning electron microscope analyses of the foamed parts showed a bimodal foam structure for thermoplastic polyurethane with a cross-linking agent and a more integral foam structure with less cell coalescence even at higher density reductions.
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Combrzyński, Maciej, Leszek Mościcki, Marcin Mitrus, Karol Kupryaniuk, and Anna Oniszczuk. "Application of extrusion-cooking technique for foamed starch-based materials." BIO Web of Conferences 10 (2018): 01004. http://dx.doi.org/10.1051/bioconf/20181001004.
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Foamed materials are widely used, mainly as a protection objects during transport of various products. Traditionally foams are produced from plastics so they are very difficult for waste management. It is the challenge for many scientific centres to develop a technology for the production of bio-based materials which can be rapidly decomposed. The task for the researcher is to obtain a relatively cheap, easy to use and completely biodegradable materials. The aim of this work was the selection of the main raw materials, functional additives and process parameters to obtain the most effective parameters of extrusion-cooking process for foamed starch-based materials. Properties of the products and processing costs were taken into account. During the study, the extrusion-cooking process was performed under various conditions: temperature, humidity, type of the die, screw rotational speed, various raw materials and additives blends. The best results were obtained for mixtures based on potato starch and with addition the foaming agent Plastron foam PDE and poly(vinyl) alcohol PVA.
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Ibrahim, Norlia Mohamad, Roshazita Che Amat, Shamshinar Salehuddin, Nur Liza Rahim, Abdul Rahim Abdul Razak, and Wei Hong Ooi. "Properties of Lightweight Concrete Composites with Mixture of Fly Ash and Concrete Sludge Aggregate." Key Engineering Materials 594-595 (December 2013): 482–86. http://dx.doi.org/10.4028/www.scientific.net/kem.594-595.482.
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Lightweight foamed concrete is a concrete made by cement slurry mixed with foam so that foamed concrete that is much lighter than conventional concrete can be produced. The objectives of this study is to develop optimal pre-foamed lightweight foamed concrete and to achieve desired density of lightweight concrete that is below 2400 kg/m3. Three samples of concrete were batching with 0%, 25% and 50% of foam respectively under mixing ratio of 1:1:2 and foam dilution ratio 1:5 to obtain optimum result. Based on the result attained, the samples achieved the bulk density ranged from 1943 kg/m3 to 2305 kg/m3. In addition, other physical characteristics of this mixture of materials show that its water absorption for all the samples was increased from 6.508% to 11.889%. This trend of results was obtained if the volume of foam presented in the concrete were increased. Furthermore, the samples achieved compression strength ranged from 22.418 MPa to 32.229 MPa with presence of foam. In summary, with additional of fly ash and concrete sludge as aggregate it can help to produce comparable concrete composites with lighter density.
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Wang, Fang, Lu Cai Wang, and Zhi Min Zhang. "Influence of Structure Parameters on Compressive Behavior of Aluminum Foam." Applied Mechanics and Materials 80-81 (July 2011): 123–27. http://dx.doi.org/10.4028/www.scientific.net/amm.80-81.123.
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Foamed aluminum has been recently developed as one of new structure functional materials due mainly to its excellent properties such as energy absorption property. It is significant to investigate the compressive behavior and energy absorption property of foamed aluminum under the condition of static and dynamic loading. The compressive deformation behavior of foamed aluminum with open pore structure was experimentally studied and the effects of the porosity, the type of materials, the pore size and the sample size were discussed in detail by means of the orthogonal experiments. The results showed that the type of materials had the most evident influence on the compressive property of foamed aluminum among the factors investigated, and that the size effects of the experimental results were observed.
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Tišler, Zdeněk, Kateřina Hrachovcová, Eliška Svobodová, Jan Šafář, and Lenka Pelíšková. "Acid and Thermal Treatment of Alkali-Activated Zeolite Foams." Minerals 9, no. 12 (November 20, 2019): 719. http://dx.doi.org/10.3390/min9120719.
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The foamed alkali-activated zeolite materials have been studied primarily in terms of mechanical and structural properties as potential substitutes for concrete and other building materials. However, they also have interesting textural and acid properties that make them much more useful, especially in the chemical industry. The aim of the study is to map in detail the influence of post-synthesis modifications of alkali-activated natural zeolite foams on their chemical, mechanical, and textural properties for possible use in catalytic and adsorption applications. Alkali-activated natural zeolite foam pellets were prepared by activation with mixed potassium hydroxide and sodium silicate activator and foamed using H2O2 solution. The foam pellets were post-synthetic modified by leaching with mineral and organic acids and calcination. The properties of the modified materials were characterised on the basis of XRF, XRD, N2 physisorption, DRIFT, SEM, NH3-TPD analyses, and the strength measurements. Our data showed that the basic clinoptilolite structure remains unchanged in the material which is stable up to 600 °C after acid leaching. In two-step leaching, the specific surface area increases to 350 m2/g and the leaching process allows the acid properties of the materials to be varied.
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Yang, Q. C., M. J. Zhang, and P. S. Liu. "Macroscopic fracture behavior of nickel foam under tension." Multidiscipline Modeling in Materials and Structures 12, no. 1 (June 13, 2016): 110–18. http://dx.doi.org/10.1108/mmms-05-2015-0025.
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Purpose – The samples of nickel foam with porosity of about 88 percent were uniaxially tensioned at room temperature, and the phenomena of tensile fracture were compared with that from the fully dense plate of metal nickel. The purpose of this paper is to investigate the differences between their behaviors of tensile fracture. Design/methodology/approach – The tensile test was carried out by using the tester of CMT-series microcomputer-controlled electronic universal testing machine. The difference of tensile fracture behavior between the nickel foam and the dense metal nickel was discussed by analyzing the load-displacement curve and the microscopical fracture. Findings – The results indicated that, nickel foam also displayed the feature of macroscopic plastic-deformation during tension, but it showed a macroscopic brittleness much more than that of the fully dense body. The axial apparent strain at the maximum load for the foamed sample was markedly less than that for the dense one. In addition, an obviously gradual course exhibited for the foamed body during tensile failure and a rapidly instant course for the dense body correspondingly. Originality/value – There have been some studies on the tensile behavior for metal foams, but much less than on the compression, and the relevant works are mostly for aluminum foam. The present work provides the investigations on the difference of tensile fracture behavior between the nickel foam and the dense metal nickel, as well as that of the corresponding samples in various cases with different tensile velocities. It is found that the porosity can make a remarkable decrease of the apparent strain at the maximum load and a significant increase of the macroscopical brittleness for the metallic nickel under tension.
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Baumberger, B. "Polyurethane Foam for Direct Injection of Foamed Seals." Journal of Cellular Plastics 22, no. 3 (May 1986): 211–21. http://dx.doi.org/10.1177/0021955x8602200303.
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Mareeva, Olga, Vladimir Ermilov, Vera Snezhko, Dmitrii Benin, and Alexander Bakshtanin. "Impact of the reinforced metal structure on the mechanical properties foamed aluminium composites at the load." Curved and Layered Structures 8, no. 1 (January 1, 2021): 318–26. http://dx.doi.org/10.1515/cls-2021-0026.
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Abstract This paper is an experimental study of the quasi-static mechanical compressive properties of the reinforced closed-cell aluminum alloy foams with different cell orientations at different strain rates. The reinforced foam samples were obtained via the powder metallurgical route. The results of the compression tests revealed that the deformation behavior and mechanical properties of foamed aluminum composites are highly dependent on the orientation of the reinforcing mesh. Differences in the deformation behavior of foams appear to be influenced by the mechanical properties of the matrix material, by foam deformation mechanisms, and by the mechanical properties of the reinforcement. The yield stress, plateau stress, densification stress, and energy absorption capacity of unreinforced foam samples improved linearly with increasing strain rate due to dynamic recrystallization and softening of the foam matrix material. The reinforced foam samples exhibit nonlinear deformation behavior. It was also found that the mechanical properties reduction of transverse reinforced foams was slightly lower compared to foams with longitudinal reinforcement at varying strain rates because of the large contribution of the mechanical properties of the reinforcement. The results of the present study can be employed to modelling and obtain impact-resistant fillers for complex structures in transport construction.
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Bagdasarov, A. S., A. I. Nesterenko, and A. Yu Pupkova. "FOAM GYPSUM PRODUCTS BASED ON LOCAL BINDERS." Herald of Dagestan State Technical University. Technical Sciences 45, no. 4 (June 27, 2019): 153–61. http://dx.doi.org/10.21822/2073-6185-2018-45-4-153-161.
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Objectives. The problems of production of porous gypsum products on a local gypsum binder in the Karachay-Cherkess Republic are considered. Method. The study is based on the method of "dry" mineralization of foams, developed at the Moscow State University of Civil Engineering. As the source materials used plaster binder brand G-6 Ust-Dzhegutinsky plaster plant. An alkyl dimethylamine oxide (amine oxide) foaming agent was chosen as a foaming agent (PO). The choice of software is made taking into account its compatibility with the gypsum binder. At the same time, software of various classes was studied. Studies were performed to obtain foamed gypsum with an average density of 900 kg / m3. Result. A technology for the production of foam gypsum is proposed, based on the technology for the production of foam concrete by the method of “dry” mineralization of foams. The choice of foaming agent was made by comparative evaluation of the studied parameters of foaming agents of various classes. A technique has been developed for designing foamed gypsum formulations to produce products of a given average density. The technique includes the determination of the flow rate of HS, water flow and foaming agent, the determination of the B / T ratio. It was proposed to design the GHG compositions based on a given design average material density (), which in this case is equal to the consumption of dihydrate gypsum (CaSO42H2O). In the proposed method of obtaining foam – gypsum masses, the distinctive feature is the use of the technological properties of dense foams with low multiplicity. The boundary conditions for obtaining wall foam-gypsum products from a local gypsum binder that meet the requirements of GOST have been determined. Conclusion. Using modern research methods, it has been established that foam-hypo products from Ust-Dzhegutinsky gypsum of grade G-6 meet the requirements of standards for building heat-insulating and construction-heatinsulating products with a density of 400-1000 kg / m 3.
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Surace, R., L. A. C. De Filippis, E. Niini, A. D. Ludovico, and J. Orkas. "Morphological Investigation of Foamed Aluminum Parts Produced by Melt Gas Injection." Advances in Materials Science and Engineering 2009 (2009): 1–9. http://dx.doi.org/10.1155/2009/506024.
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Porous metal materials are a new class of materials with low densities, large specific surface, and novel physical and mechanical properties. Their applications are extremely varied: for light weight structural components, for filters and electrodes, and for shock or sound absorbing products. Recently, interesting foaming technology developments have proposed metallic foams as a valid commercial chance; foam manufacturing techniques include solid, liquid, or vapor state methods. The foams presented in this study are produced by Melt Gas Injection (MGI) process starting from melt aluminum. The aim of this investigation is to obtain complex foamed aluminum parts in order to make the MGI more flexible. This new method, called MGI-mould process, makes possible to produce 3D-shaped parts with complicated shape or configuration using some moulds obtained by traditional investment casting process.
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Gawdzińska, K., L. Chybowski, and W. Przetakiewicz. "Study of Thermal Properties of Cast Metal- Ceramic Composite Foams." Archives of Foundry Engineering 17, no. 4 (December 20, 2017): 47–50. http://dx.doi.org/10.1515/afe-2017-0129.
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Abstract Owing to its properties, metallic foams can be used as insulation material. Thermal properties of cast metal-ceramic composite foams have applications in transport vehicles and can act as fire resistant and acoustic insulators of bulkheads. This paper presents basic thermal properties of cast and foamed aluminum, the values of thermal conductivity coefficient of selected gases used in foaming composites and thermal capabilities of composite foams (AlSi11/SiC). A certificate of non-combustibility test of cast aluminum-ceramic foam for marine applications was included inside the paper. The composite foam was prepared by the gas injection method, consisting in direct injection of gas into liquid metal. Foams with closed and open cells were examined. The foams were foaming with foaming gas consisting of nitrogen or air. This work is one of elements of researches connected with description of properties of composite foams. In author's other works acoustic properties of these materials will be presented.
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Zhang, Xiuzhi, Qing Yang, Qinfei Li, Heng Chen, Guofa Zheng, and Xin Cheng. "Effect of Phenolic Particles on Mechanical and Thermal Conductivity of Foamed Sulphoaluminate Cement-Based Materials." Materials 12, no. 21 (November 1, 2019): 3596. http://dx.doi.org/10.3390/ma12213596.
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Foamed concrete materials based on sulpoaluminate cement were prepared by the chemical foaming method. The effects of water–cement ratio, foaming agent, and foaming stabilizer on the mechanical and thermal properties of foamed concrete were studied. Meanwhile, a portion of cement was replaced with foamed phenolic particles to further optimize the performance of foamed concrete; the results show that when the water–cement ratio was 0.53, the foaming agent content was 5%, the foam stabilizer was 1%, and the substitution of phenolic particles was 20%, the performance indexes of foamed concrete were the best. Methods, describing briefly the main methods or treatments applied: dry density was 278.4 kg/m3, water absorption was 19.9%, compressive strength was 3.01 MPa, and thermal conductivity was 0.072 W/(m·K). By the pore structure analysis of the foamed concrete suing Micro-CT, it was found that when the replacement amount of phenolic particles was 20%, the pore size of foamed concrete was relatively uniform, the minimum D90 was 225 μm respectively. The combination of organic and inorganic matrix and optimized pore structure improved the performance of foamed concrete.
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Mimini, Vebi, Vasken Kabrelian, Karin Fackler, Hubert Hettegger, Antje Potthast, and Thomas Rosenau. "Lignin-based foams as insulation materials: a review." Holzforschung 73, no. 1 (December 19, 2018): 117–30. http://dx.doi.org/10.1515/hf-2018-0111.
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AbstractThe bulk use of renewable polymers is currently largely limited to cellulose and, less significantly, hemicelluloses. Technical lignins are only applied in novel materials to a rather limited extent, although bulk lignin utilization is a worldwide research object. Native lignins, which belong to the second or third most abundant biopolymers of terrestrial plants, are mostly used in the form of technical lignins from wood pulping processes; they are employed in low-performance sectors or simply burnt for the generation of energy. Technical lignins are available in huge quantities and have a large application potential, mainly in areas where their aromatic nature is of relevance. This review presents the state of the art of foamed lignin-based polymers (lignofoams) as high-performance insulation materials. In the focus of this presentation are the fundamental foaming principles and influential agents that have an improvement potential concerning the matrix interactions between technical lignins (including lignosulfonates) and a copolymer in foam composites. The different approaches for foam preparation are critically compared. In general, the reviewed papers disclose that the lignin part in foams should be less than 37%. There are significant difficulties to improve the properties of lignofoams, and thus intensive research is needed to find better formulations and new technologies.
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Cui, Yong, and Dongmin Wang. "Effects of Water on Pore Structure and Thermal Conductivity of Fly Ash-Based Foam Geopolymers." Advances in Materials Science and Engineering 2019 (January 3, 2019): 1–10. http://dx.doi.org/10.1155/2019/3202794.
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The influence of the water-to-solid ratio (W/S) on the viscosity, pore characteristics, bulk density, compressive strength, and thermal conductivity of foamed fly ash-based geopolymers with thermal conductivity less than 0.065 W/(m·K) was investigated, and their properties and cost analysis were also compared with that of foamed ordinary Portland cement (OPC). When the W/S varied from 0.38 to 0.5, the apparent viscosity of geopolymer paste 15 min after the preparation decreased significantly from 168 Pa·s to 6 Pa·s. The increasing W/S ratio contributed to the rise of the number of microcapillaries (φ < 50 nm) and macrocapillaries (50 nm < φ < 50 μm) but contributed to the decline of artificial air pores (φ > 50 μm). The refinement of pore characteristics lowered the 28 d thermal conductivity of foamed geopolymers from 0.06 W/(m·K) to 0.048 W/(m·K). Although the slight increase of total porosity of foamed geopolymers from 89% to 92% with the increase of the W/S ratio weakened their 28 d compressive strength from 0.75 MPa to 0.45 MPa, this strength still meets the Ordinary Portland Cement (OPC) based Foam Insulation Board standard of JC/T2200-2013 (>0.4 MPa for 0.25 g/cm3). The production cost of foamed geopolymers was slightly higher by 1.1–1.5 times than that of foamed OPC. However, considering the more beneficial effect of environmental load reductions and better mechanical and thermal properties of foamed geopolymers than those of foamed OPC, slightly higher cost would be acceptable for practical application.
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Kadela, Marta, Andrzej Cińcio, and Marcin Kozlowski. "Degradation Analysis of Notched Foam Concrete Beam." Applied Mechanics and Materials 797 (November 2015): 96–100. http://dx.doi.org/10.4028/www.scientific.net/amm.797.96.
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Nowadays, lightweight foamed concrete (LFC) is increasingly being used for structural purposes. Physical and mechanical properties of LFC are unlike the properties of traditional concrete thus constitutive models for concrete may not be used directly to describe its the fracture behavior. The paper presents an attempt to adapt the elastoplastic model with degradation known as Barcelona model for this purpose. The constitutive model is traditionally used for non-linear analyses of concrete and masonry structures. However, when it is used to describe behavior of non-traditional material such as foamed concrete, its parameters must be calibrated. Moreover, the results from Barcelona model are compared with XFEM method of modeling discontinuities in materials. The results of numerical simulations of three-point bending foamed beam with an initial notch are presented.
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Yatsenko, E. A., B. M. Goltsman, and L. A. Yatsenko. "Investigation of the Raw Materials' Composition and Ratio Influence on the Structure and Properties of the Foamed Slag Glass." Materials Science Forum 843 (February 2016): 183–88. http://dx.doi.org/10.4028/www.scientific.net/msf.843.183.
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The composition of the foam glass based on thermal power plant’s ash-slag waste – foamed slag glass – was developed. The synthesis of the samples based on the most widespread foaming agents was conducted at various temperatures. The structure and properties of the obtained samples were defined, the relationship between the type and amount of the introduced foaming agents and changes in the structure and properties of the samples were established. The best type of foaming agent for the synthesis of foamed slag glass has been selected. The production technology for products based on foamed slag glass was developed.
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Wang, Qing, Ning Wang, Zhao Yang Ding, and Tao Jun Wu. "Influences of Firing Process System on Foam Glass Properties." Advanced Materials Research 721 (July 2013): 258–61. http://dx.doi.org/10.4028/www.scientific.net/amr.721.258.
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Waste glass and polishing waste residue as raw materials were used to make foamed glass. The preparation of firing technology was optimized and the powder burning method was used, by which the foam glass possess good performance, such as light weight, high strength, low thermal conductivity. Results show that sintering temperature and foaming temperature influence the specific strength of foam glass greatly, and the optimal preparation process of foam glass was confirmed: sintering temperature is 1050°C, foaming temperature is 870°C minutes, foaming time is 35min.
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Löhner, Martin, and Dietmar Drummer. "Influence of Processing Parameters in Reaction Injection Foam Molding for Multi-Layer Parts on Foam Structure and Mechanical Properties." Applied Mechanics and Materials 805 (November 2015): 131–38. http://dx.doi.org/10.4028/www.scientific.net/amm.805.131.
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Reaction injection molding is a plastic processing method to produce net shape parts using reactive systems. By integrating semi-finished products as inserts, complex multi-layer parts can be generated in highly integrative and energy efficient processes. The material by far mostly used is polyurethane, a polymer which results from the reaction of isocyanate and polyol. By adding blowing agents, like for example water, to the polyol component, foamed parts can be realized. In contrast to thermoplastic injection molding a chemical reaction takes part during molding within the cavity. Therefore the processing parameters have a significant effect on this chemical reaction and on the properties of the finished part.In this work the influences of different processing parameters like for example mold temperature and injection volume on the resulting foam structure are investigated for reaction injection foam molding. Therefore multi-layer parts based on polyurethane materials (thermoplastic and reactive) were molded varying relevant processing parameters. The foaming took place within an open cavity. The resulting foam structures were characterized using scanning electron microscopy (SEM). Additional the multi-layer parts were characterized mechanically to reveal the resulting effects on the mechanical properties of parts containing a foamed reactive polyurethane component.
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Amran, Mugahed, Roman Fediuk, Nikolai Vatin, Yeong Huei Lee, Gunasekaran Murali, Togay Ozbakkaloglu, Sergey Klyuev, and Hisham Alabduljabber. "Fibre-Reinforced Foamed Concretes: A Review." Materials 13, no. 19 (September 28, 2020): 4323. http://dx.doi.org/10.3390/ma13194323.
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Foamed concrete (FC) is a high-quality building material with densities from 300 to 1850 kg/m3, which can have potential use in civil engineering, both as insulation from heat and sound, and for load-bearing structures. However, due to the nature of the cement material and its high porosity, FC is very weak in withstanding tensile loads; therefore, it often cracks in a plastic state, during shrinkage while drying, and also in a solid state. This paper is the first comprehensive review of the use of man-made and natural fibres to produce fibre-reinforced foamed concrete (FRFC). For this purpose, various foaming agents, fibres and other components that can serve as a basis for FRFC are reviewed and discussed in detail. Several factors have been found to affect the mechanical properties of FRFC, namely: fresh and hardened densities, particle size distribution, percentage of pozzolanic material used and volume of chemical foam agent. It was found that the rheological properties of the FRFC mix are influenced by the properties of both fibres and foam; therefore, it is necessary to apply an additional dosage of a foam agent to enhance the adhesion and cohesion between the foam agent and the cementitious filler in comparison with materials without fibres. Various types of fibres allow the reduction of by autogenous shrinkage a factor of 1.2–1.8 and drying shrinkage by a factor of 1.3–1.8. Incorporation of fibres leads to only a slight increase in the compressive strength of foamed concrete; however, it can significantly improve the flexural strength (up to 4 times), tensile strength (up to 3 times) and impact strength (up to 6 times). At the same time, the addition of fibres leads to practically no change in the heat and sound insulation characteristics of foamed concrete and this is basically depended on the type of fibres used such as Nylon and aramid fibres. Thus, FRFC having the presented set of properties has applications in various areas of construction, both in the construction of load-bearing and enclosing structures.
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Marinzuli, G., L. A. C. De Filippis, R. Surace, and A. D. Ludovico. "A Preliminary Study on Adhesion on Steel Cylinder Filled with Aluminum Foam." International Journal of Metals 2013 (December 23, 2013): 1–14. http://dx.doi.org/10.1155/2013/878032.
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In the last decades, metallic foams found commercial and industrial interests, thanks to their physical properties combined with good mechanical characteristics. Metal foam structures are very light and they can be used to reduce the weight of machinery without compromising the mechanical behavior. In this work, a study of the direct junction of metal foam with metal massive components was carried out. Aluminium foams were manufactured starting from commercial foamable precursors. First of all, attention was paid to the repeatability of foaming process. Then, a direct connection between the foamed samples and the steel shell elements was pursued. The materials that seemed to facilitate the formation of an intermetallic layer were studied and the geometry of the steel mould and the most useful way to place the precursor in the steel mould and then in the furnace were considered. To evaluate the produced aluminum foam, morphological and mechanical characterizations were done. Results showed that, keeping constant the contour conditions, it was possible to control the process and a first result, in terms of interaction between foam and mould, was obtained using an X210Cr12 steel as mould material. The SEM observation revealed the presence of an intermetallic phase.
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Rokkonen, Teijo, Pia Willberg-Keyriläinen, Jarmo Ropponen, and Tero Malm. "Foamability of Cellulose Palmitate Using Various Physical Blowing Agents in the Extrusion Process." Polymers 13, no. 15 (July 23, 2021): 2416. http://dx.doi.org/10.3390/polym13152416.
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Polymer foams are widely used in several fields such as thermal insulation, acoustics, automotive, and packaging. The most widely used polymer foams are made of polyurethane, polystyrene, and polyethylene but environmental awareness is boosting interest towards alternative bio-based materials. In this study, the suitability of bio-based thermoplastic cellulose palmitate for extrusion foaming was studied. Isobutane, carbon dioxide (CO2), and nitrogen (N2) were tested as blowing agents in different concentrations. Each of them enabled cellulose palmitate foam formation. Isobutane foams exhibited the lowest density with the largest average cell size and nitrogen foams indicated most uniform cell morphology. The effect of die temperature on foamability was further studied with isobutane (3 wt%) as a blowing agent. Die temperature had a relatively low impact on foam density and the differences were mainly encountered with regard to surface quality and cell size distribution. This study demonstrates that cellulose palmitate can be foamed but to produce foams with greater quality, the material homogeneity needs to be improved and researched further.
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Sohn, Joo, Hyun Kim, and Sung Cha. "Bio-Based Foamed Cushioning Materials Using Polypropylene and Wheat Bran." Sustainability 11, no. 6 (March 20, 2019): 1670. http://dx.doi.org/10.3390/su11061670.
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This study investigated bio-based plastic cushioning materials foamed through water phase-change characteristics using the natural by-product wheat bran. Experiments were carried out while increasing the wheat bran content from 20% to 70% in a blended composite material of polypropylene (PP) and wheat bran (WB). From the experimental results, we were able to prepare a bio-based plastic cushion that contained a high amount of natural materials, with a bran content of over 50%. This indicates the possibility of meeting the criteria for biodegradable plastics, as well as bio-based plastics. In this study, by inducing a foaming ratio of 95% or more, a volume-expansion ratio from 16 times to over 62 times was achieved. In addition, the optimal mixing condition for inducing a high-expansion foam was when the mixing ratio of PP and WB was 50/50, and the water content of the foaming agent was 25 parts per hundred resin. Finally, dynamic cushioning characteristics of PP50/WB50 composite foam prepared in this study and Polystyrene (PS) bead based commercial products were compared. The composite foam of this study showed comparable values, confirming commercialization possibility.
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Othman, Rokiah, Ramadhansyah Putra Jaya, Khairunisa Muthusamy, MohdArif Sulaiman, Youventharan Duraisamy, Mohd Mustafa Al Bakri Abdullah, Anna Przybył, et al. "Relation between Density and Compressive Strength of Foamed Concrete." Materials 14, no. 11 (May 31, 2021): 2967. http://dx.doi.org/10.3390/ma14112967.
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This study aims to obtain the relationship between density and compressive strength of foamed concrete. Foamed concrete is a preferred building material due to the low density of its concrete. In foamed concrete, the compressive strength reduces with decreasing density. Generally, a denser foamed concrete produces higher compressive strength and lower volume of voids. In the present study, the tests were carried out in stages in order to investigate the effect of sand–cement ratio, water to cement ratio, foam dosage, and dilution ratio on workability, density, and compressive strength of the control foamed concrete specimen. Next, the test obtained the optimum content of processed spent bleaching earth (PSBE) as partial cement replacement in the foamed concrete. Based on the experimental results, the use of 1:1.5 cement to sand ratio for the mortar mix specified the best performance for density, workability, and 28-day compressive strength. Increasing the sand to cement ratio increased the density and compressive strength of the mortar specimen. In addition, in the production of control foamed concrete, increasing the foam dosage reduced the density and compressive strength of the control specimen. Similarly with the dilution ratio, the compressive strength of the control foamed concrete decreased with an increasing dilution ratio. The employment of PSBE significantly influenced the density and compressive strength of the foamed concrete. An increase in the percentage of PSBE reduced the density of the foamed concrete. The compressive strength of the foamed concrete that incorporated PSBE increased with increasing PSBE content up to 30% PSBE. In conclusion, the compressive strength of foamed concrete depends on its density. It was revealed that the use of 30% PSBE as a replacement for cement meets the desired density of 1600 kg/m3, with stability and consistency in workability, and it increases the compressive strength dramatically from 10 to 23 MPa as compared to the control specimen. Thus, it demonstrated that the positive effect of incorporation of PSBE in foamed concrete is linked to the pozzolanic effect whereby more calcium silicate hydrate (CSH) produces denser foamed concrete, which leads to higher strength, and it is less pore connected. In addition, the regression analysis shows strong correlation between density and compressive strength of the foamed concrete due to the R2 being closer to one. Thus, production of foamed concrete incorporating 30% PSBE might have potential for sustainable building materials.
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Manakova, N. K., T. K. Ivanova, O. V. Suvorova, and I. P. Kremenetskaya. "Use of a serpentine-containing additive for obtaining thermal insulation materials." Transaction Kola Science Centre 11, no. 3-2020 (November 25, 2020): 75–81. http://dx.doi.org/10.37614/2307-5252.2020.3.4.016.
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The possibility of utilizing the used magnesia-silicate reagent as an active additive to foam silicates based on a silica-containing matrix was studied. Foamed materials with an ordered structure and improved physical and technical characteristics were obtained, which can be recommended for use as heat-insulating materials to increase energy conservation in adverse climatic conditions.
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Zhang, Duo, Weifeng Wang, Jun Deng, Hu Wen, and Xiaowei Zhai. "Experimental Study and Application of LASC Foamed Concrete to Create Airtight Walls in Coal Mines." Advances in Materials Science and Engineering 2020 (January 23, 2020): 1–11. http://dx.doi.org/10.1155/2020/6804906.
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If an airtight wall in a coal mine leaks air, it may cause spontaneous combustion of residual coal in the gob and even cause a full-blown fire or gas explosion. In this study, we developed a new type of foamed concrete, low-alkalinity sulphoaluminate cement (LASC), to control air leakage. The performance of filling materials that were prepared by adding various dosages of foam to LASC was studied. The longer the curing period for the foam filling material of LASC, the better the crystallinity of the hydrated product. With an increasing foam dosage, the initial setting time gradually extends while the fluidity of the foam slurry decreases. The bubble rate of the filling material increases and the density decreases with increasing foam dosage. The compressive strength of the LASC filling material decreases with increasing foam dosage and increases with increasing curing time. In the LASC filling materials, the optimal volume ratio of foam dosage to gel slurry is 2. The crystallinity, initial gel time, and compressive strength of the LASC foaming materials are better than those of ordinary Portland cement (OPC) foaming materials. When the crossheading is filled with LASC foam cement, the deformation of the surrounding rock is less than 19 cm, and the air leakage prevention is better than that achieved with loess and fly-ash-cement foam. Thus, the proposed LASC foam material can be applied to the filling of the crossheading to efficiently prevent leakage in underground coal mines.
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Falliano, Devid, Luciana Restuccia, and Ernesto Gugliandolo. "A simple optimized foam generator and a study on peculiar aspects concerning foams and foamed concrete." Construction and Building Materials 268 (January 2021): 121101. http://dx.doi.org/10.1016/j.conbuildmat.2020.121101.
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GONG, Wei, Yu Long MA, Da Ming BAN, Xiao Gang YIN, Li HE, and Hai FU. "Study of the Sound Absorption Performance of Ethylene-Vinyl Acetate Foam Materials." Materials Science 25, no. 4 (June 27, 2019): 427–32. http://dx.doi.org/10.5755/j01.ms.25.4.19139.
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Ethylene-Vinyl Acetate (EVA) polymer foam was prepared using a mold for this investigation. The effect of the cell structure parameters and pore filling gas type on the sound absorption performance of the EVA foam materials were analyzed in terms of their sound absorption capability. The results show that the cell size, cell wall thickness and pore filling gas type have significant influence on the sound absorption performance. When the cell size is 71.3 μm, at low frequency (1000 Hz) the absorption coefficient was the largest at 0.487 and the absorption effect was good. With the increase of the cell wall thickness, the peak value of the sound absorption coefficient first increased and then decreased, and gradually transferred to the low frequency area. When the cell wall thicknesses were 14.3 μm, the foam material had optimal sound absorption properties. The cell filling gas was hydrogen, the EVA foam material had optimal sound absorption effect, and the sound absorption peak value was 0.553 at 800 Hz in the low frequency range (Ⅰ), the sound absorption performance of the foamed materials was ideal.
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Xu, Changyu, Lijun Han, Maolin Tian, Yajie Wang, and Yuhao Jin. "Study on Foamed Concrete Used as Gas Isolation Material in the Coal Mine Goaf." Energies 13, no. 17 (August 25, 2020): 4377. http://dx.doi.org/10.3390/en13174377.
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In view of the serious threat of gas accumulation in the coal mine goaf and the limitations of the existing gas sealing materials, the orthogonal experiment was developed to study a new type of foamed concrete for mine gas sealing. Dry density, gas permeability, and compressive strength were studied as the material indicators according to the demands of the gas isolation material in the coal mine goaf, and the experimental results showed that foam content was the most important factor. Meanwhile, the optimum mix was selected according to the influence of foam content as well as the engineering requirement. Then two application modes of this foamed concrete for goaf gas isolation were put forward, after which the convection-diffusion model of gas was built by COMSOL Multiphysics (COMSOL Inc., Stockholm, Sweden) to reveal the mechanism of different application modes using the parameters of the new foamed concrete. Simulation results showed that this foamed concrete used as isolating material for goaf gas could significantly decrease the gas concentration in workface, which can provide a reference for similar engineering.
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Park, Byung Kyu, Charn-Jung Kim, Dong Eui Kwon, and Youn-Woo Lee. "Design and Fabrication of Partially Foamed Grid Structure Using Additive Manufacturing and Solid State Foaming." Processes 8, no. 12 (December 3, 2020): 1594. http://dx.doi.org/10.3390/pr8121594.
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A partially foamed lattice structure based on synthetic polymers was considered as a functionally graded materials due to their unique properties. In this study, a copolymer is manufactured to be porous functional materials by physical foaming technology, using carbon dioxide. Through morphological characterization, using scanning electron microscope, we identified a potential to fabricate partially foamed structures with micropores. We showed that variation of post-foaming temperature can tune the pore size distribution in the range of 0.9 to 30 μm. Thermal data of the foam grid from differential scanning calorimeter showed some shifts in glass transition, cold crystallization, and melting points. Mechanical strength and thermal conductivity were also measured to find rationale of thermal insulation with tunable mechanical strength and to elucidate the actual 3D lattice foam of a copolymer.
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Park, Byung Kyu, Charn-Jung Kim, and Byeong Jun Lee. "Effect of Foaming Temperature on Microstructure, Mechanical Properties and Flame Spread Rate in PET–PEN Copolymer." Energies 14, no. 4 (February 11, 2021): 957. http://dx.doi.org/10.3390/en14040957.
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Polymer foams are expanding their applications into functional materials. Partial foam structure has been fabricated in polyethylene terephthalate–polyethylene naphthalate (PET–PEN) copolymer by solid state foaming. Through SEM image analyses, a potential to fabricate gradient foam structures with micropores and unfoamed skin layers has been identified. The post-foaming temperature Tf tune the pore size distribution. Radial distribution of micromechanical properties, indentation hardness and elastic modulus were measured for the partial foam and their values were around 0.12 GPa and 2.0 GPa, respectively, for the outer foamed region. Foaming temperature affects the glass transition temperature Tg, the coefficient of thermal expansion and the flame spreading rate. For the range of Tf ≤ 60°C, thermal expansion coefficients for T > Tg are about 0.5 m/m°C (steep expansion group, SEG). When Tf is above 80 °C, they are around 0.02 m/m°C (mild expansion group, MEG). The burning rate of SEG is 2.8 times higher than that of MEG.
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Li, Jing, and Guo Zhong Li. "Influence of Waterproofing Agent on Foamed Thermal Insulation Materials and its Mechanism Inquiry." Applied Mechanics and Materials 711 (December 2014): 469–72. http://dx.doi.org/10.4028/www.scientific.net/amm.711.469.
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Lightweight aggregates glazed hollow bead, cement, foaming agent, foam stabilizer and waterproofing agents as the main raw material, produce foamed thermal insulation materials by vibration shaping. By adding emulsified stearic acid and methyl stearate alcohol organosilicon waterproofing agent, the effects of two types of waterproofing agent on quality of water absorption of foamed thermal insulation materials were studied, and the related mechanisms were discussed. Results show that the waterproofing effect of organosilicon waterproofing agents is superior to emulsified stearic acid, when the content of emulsified stearic acid and organosilicon waterproofing agent are 7% and 4% respectively, 2h,24h water absorption rate of samples are 18.34%, 45.45% and 14.45%, 32.83%.
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Li, Xiao Long, and Guo Zhong Li. "Study on the Performance of New Foamed Cement Insulation Material." Advanced Materials Research 648 (January 2013): 112–15. http://dx.doi.org/10.4028/www.scientific.net/amr.648.112.
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In this experiment, cement, fly ash, quicklime, foaming agent and foam stabilizer were used as raw materials to prepare the new foamed cement insulation material. Single-factor tests were designed to study the influence of different dosages of foaming agent, foam stabilizer and quicklime on the material properties. The optimum ratio was determined: content of fly ash was 25%, water-cement ratio was 0.37, content of foaming agent was 4.5%, content of foam stabilizer was 1.2% and content of quicklime was 1.5%. The material is tested: 3d compressive strength of the material is 1.049MPa, 3d flexural strength of the material is 0.608MPa.
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Kausar, Ayesha. "Fabrication of short glass fiber reinforced phenol-formaldehyde-lignin and polyurethane-based composite foam: mechanical, friability, and shape memory studies." Journal of Polymer Engineering 38, no. 1 (January 26, 2018): 33–40. http://dx.doi.org/10.1515/polyeng-2016-0289.
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Abstract In this research effort, phenol-formaldehyde-lignin (PFL) resin was prepared using phenol, formaldehyde, and lignin via a simple approach. The PFL-polyurethane (PFL-PU) was prepared using PU prepolymer and PFL resin. The blend components were then foamed via addition of Tween 80 surfactant and n-pentane as the blowing agent. Short glass fiber was reinforced in the blend sample to attain high performance composite foams. The composite foams were characterized for structure, morphology, stress-strain behavior, friability tests, and shape memory characteristics. Scanning electron microscopy showed a layered, porous, and distorted hexagonal shaped foam structure. The cell size ranges from 10 to 20 μm for PFL-PU-short glass fiber (SGF) Foam with 10–20 wt.% fiber loading. PFL-PU Foam had compression strength and strain of 48.3 MPa and 48.2%. The PFL-PU-SGF 1–20 Foam showed increase in strength from 55.1 to 101.7 MPa and decrease in strain from 57.8% to 35.8% due to filler addition. At temperature above Tg (130°C), the strain was increased up to 45.11%. The shape fixity was improved up to the addition of 10 wt.% filler where the value of 92.1% was achieved with shape recovery of 95%.
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Ibrahim, Wan Mastura Wan, Kamarudin Hussin, Mohd Mustafa Al Bakri Abdullah, Aeslina Abdul Kadir, Laila Mardiah Deraman, and Andrei Victor Sandu. "Influence of Foaming Agent/Water Ratio and Foam/Geopolymer Paste Ratio to the Properties of Fly Ash-based Lightweight Geopolymer for Brick Application." Revista de Chimie 68, no. 9 (October 15, 2017): 1978–82. http://dx.doi.org/10.37358/rc.17.9.5805.
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Nowadays, the demand for lightweight building materials has been growing worldwide. This paper presents an investigation on the use of waste materials of fly ash as a source materials for the production of lightweight geopolymer by using foaming agents. The key properties for the foamed geopolymer namely density, compressive strength, and water absorption were investigated. The chemical composition of materials and morphology analysis were studied to find the microstructure properties of foamed geopolymer. The foamed geopolymer were prepared by combination of 12 M Sodium Hydroxide (NaOH) solution and Sodium Silicate (Na2SiO3) solution. The ratio of Na2SiO3/NaOH and ratio of fly ash/alkaline activator were kept constant at 2.5 and 2.0, by mass respectively. The effect of different ratio of foaming agent/water and foam/geopolymer paste were investigated at 7 days of ageing and cured at 80�C for 24 hours. In general, the results showed that the fly ash-based lightweight geopolymer has good potential as brick application.
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Bogusz, Paweł, Roman Gieleta, Marcin Konarzewski, and Michał Stankiewicz. "Crushing Behaviour of the PVC Foam Loaded with Beaters of Various Shapes." Acta Mechanica et Automatica 12, no. 1 (March 1, 2018): 23–30. http://dx.doi.org/10.2478/ama-2018-0004.
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AbstractStatistically, at least 50% of all injuries experienced by police officers in the line of duty are due to assaults with blunt objects. Therefore, vests used by the police should provide not only good ballistic resistance, but also good protection against such threats. Foamed materials are possible to be used for body protectors or inserts of protective clothes. The effects of dynamic impact with beaters of different shapes onto behaviour of polymeric foamed material were determined. There were used four types of beaters: flat, cylindrical, edgy and cornered. Strikes with blunt objects such as a flat board, baseball bat, edgy brick, pavement brick or a sharp stone, to which a protective ware can be subjected, were simulated. The impact load was applied to the rectangular specimens, made of polyvinyl chloride foam, with a usage of a drop hammer. Plots of force versus compression for all the tested samples were obtained and analysed. The effects of impacts with beaters of different shapes onto foamed material samples were presented. A shape of the blunt object significantly influences crushing behaviour of the foamed material. The impact energy of a flat beater is absorbed effectively on a short distance, since it is spread on a relatively large surface. The cylindrical and edgy beaters did not cause fragmentation of the samples, however, on the upper surfaces of the samples, permanent deformations mapping the beaters shapes as well as some cracks occurred. An impact with a sharp object, for example, a cornered beater is very difficult to be neutralized by the foam material, because it is cumulated on a small area.
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Jia, Cai Yun, Rui Ding, Jun Cheng Liu, An Fa Liu, and Dong Xiao Teng. "Effects of Al(OH)3 on the Structure and Properties of Foam Ceramics Cemented by Phosphate." Advanced Materials Research 1120-1121 (July 2015): 21–26. http://dx.doi.org/10.4028/www.scientific.net/amr.1120-1121.21.
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High alumina foam ceramics products with low density, high specific surface area, low thermal conductivity, corrosion resistance and other excellent physical and chemical properties are suitable for chemical, metallurgy and other related fields [1-4]. Alumina foam ceramics that compression strength increased by 200%, was prepared by Rizwan Ahmad through impregnation process using foamed rubber [5]. However foamed rubber was expensive and could be decomposed creating poisonous gases at high temperature. Zhou l z [6] prepared mullite porous ceramics with high strength by gel-casting method. Gel-casting is an effective method for preparation of ceramics products with large size and complicated shape. Fiber reinforced dense ceramics composite materials with excellent performance have been studied widely [7-10], it is also an important issue to adequately investigate the reinforcement of porous ceramics with fiber.