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Dissertations / Theses on the topic 'Foam. Foamed materials'
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Miller, Erin Ashley. "Structure and mechanics of solid foam /." Thesis, Connect to this title online; UW restricted, 2005. http://hdl.handle.net/1773/9633.
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Stone, Robert Michael 1957. "Shear modulii for cellular foam materials." Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/277020.
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The use of cellular foam as a core material in light-weight structural applications is of considerable interest. However, advances in this technology have been limited due to the lack of information concerning the macroscopic material behavior of cellular foams. Of particular interest in the design of composite structures is the shear modulus, G, of the core material, which must be established with a high degree of accuracy. Current ASTM test methods for shear modulus determination were researched and found inadequate for testing cellular foam materials. The difficulty in testing foam and the inaccuracies associated with the standard test methods established the need for the development of a test method for these materials. The test method (test fixture and test procedure) developed for cellular foam materials is presented. The design of the test fixture and the finite element analysis performed to determine fixture accuracy are discussed in detail. Additionally, the test procedure is presented, as well as the results for the 32 tests performed.
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Kavi, Halit Güden Mustafa. "Investigation of compression mechanical behaviour of aluminum foam filled metal tubes/." [s.l.]: [s.n.], 2004. http://library.iyte.edu.tr/tezler/master/makinamuh/T000488.pdf.
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Di, Prima Matthew Allen. "Thermo-mechanical and micro-structural characterization of shape memory polymer foams." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/28178.
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Thesis (M. S.)--Materials Science and Engineering, Georgia Institute of Technology, 2009.Committee Chair: Gall, Ken; Committee Co-Chair: McDowell, David; Committee Member: Guldberg, Robert; Committee Member: Sanderson, Terry; Committee Member: Shofner, Meisha; Committee Member: Tannenbaum, Rina.
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Anghelescu, Mihnea S. "Thermal and Mechanical Analysis of Carbon Foam." View abstract, 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:3353337.
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Rickles, Stacey A. "Microstructural and compressive properties of a metal/ceramic syntactic foam." Thesis, Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/19677.
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Zhang, Lizhong. "Physical, mechanical, thermal, and viscoelastic properties of water-blown rigid polyurethane foam containing soy flours /." free to MU campus, to others for purchase, 1998. http://wwwlib.umi.com/cr/mo/fullcit?p9924871.
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Gopalan, Sriram. "Quasi-static and dynamic mechanical characterization of reinforced polyurethane foam /." free to MU campus, to others for purchase, 2003. http://wwwlib.umi.com/cr/mo/fullcit?p1418024.
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Heavner, Mark E. "Pitch foam production by use of physical blowing agents." Morgantown, W. Va. : [West Virginia University Libraries], 2006. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4769.
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Thesis (M.S.)--West Virginia University, 2006.Title from document title page. Document formatted into pages; contains xi, 107 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 98-101).
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Bhavsar, Harshad. "Effect of partially defatted soy flour on physical and microbial properties of water-blown rigid polyurethane foam /." free to MU campus, to others for purchase, 2004. http://wwwlib.umi.com/cr/mo/fullcit?p1422911.
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Jhaver, Rahul Tippur Hareesh V. "Compression response and modeling of interpenetrating phase composites and foam-filled honeycombs." Auburn, Ala., 2009. http://hdl.handle.net/10415/1839.
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Heidrich, Dario, Eric Brückner, and Michael Gehde. "Correlations between injection molding and welding of microcellular materials." Universitätsbibliothek Chemnitz, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-230272.
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Due to the rising demand of light-weight constructions as well as the conservation of resources, the density and weight of thermoplastic parts could be influenced significantly by using the thermoplastic foam injection molding process. The structure of the foam injection molded part, which typically means solid surface layers and a cellular core, usually results in a weight saving. Furthermore the materials structure leads to an increasing of the specific bending stiffness with a simultaneous low tendency to warp.
The present study was aimed to analyze the interactions between microcellular structure, joining process and the resulting mechanical properties of the molded part. Therefore, the microcellular injection molding process (MuCell®) as well as the vibration welding were used. Whereas the established welding processes for solid injection molded parts have already achieved a high degree of perfection within the last decades, the joining of microcellular thermoplastics entails several specific characteristics, because the injection foaming process highly influences the basic material properties. In contrast to solid materials, the weld seam properties after joining are mainly affected by the design constraints of the microcellular structure.
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Dal, Ben Matteo. "hiResilient response and performance of bitumen stabilized materials with foam incorporating reclaimed asphalt." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86376.
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Thesis (PhD)--Stellenbosch University, 2014.ENGLISH ABSTRACT: The increased use of reclaimed asphalt (RA) in Bitumen Stabilised Materials (BSMs), shortcomings in the existing design guidelines and manuals and ongoing developments in the concepts and understanding of these materials require further research into the fundamental properties and behaviour of BSMs. The state-of-the-art of foamed bitumen techniques is reviewed in the literature study. Current best practices in the design of BSMs and pavements incorporating such materials are also included in this literature study. Shortcomings and areas for further improvement of the design practice have been identified. With new environmental legislation, the importance of BSM technology including RA as an environmentally-friendlier and more sustainable construction technique is set to increase in the coming years. Changes in the behaviour of materials and failure mechanisms of BSM mixes are long-term phenomena. This implies that the study of the physico-chemical and mechanical properties of the mixes with increasing amount of RA is vital. Therefore, fundamental understandings of moisture damage and thermo-physical characteristics, which are related to material properties, are required. The main objective of this study is to advance BSM technology by assessing the influence of the selected materials on durability behaviour, temperature distribution and long-term performance in all phases of application (i.e. mix design, construction, and in-service condition). This study begins with a comprehensive literature review of research dealing with the interactions between RA and mineral aggregates. The properties of RA and mineral aggregates were reviewed. This was followed by a review into the mechanical properties of BSM-foam mixes with high percentage of RA and its durability performance. Factors influencing the temperature gradient of BSMs were then identified. Achieving a better understanding of the fundamental performance properties and temperature influence on the behaviour of BSMs with high percentage of RA is one of the key factors of this research, with a view to using the extended knowledge for improvements to current mix design and structural design practices. Finally, the fundamental theories on thermo-conductivity and the mechanical properties of the BSM were used to create a relationship between temperature and mechanical properties in a pavement section. A laboratory testing programme was set up to study the properties and behaviour of BSMs and to establish links with the compositional factors, i.e. the type of binder used, the percentage of RA in the mix and the addition of a small amount of cement as active filler. BSMs were blended in three different proportions of RA and good quality crushed stone materials: 100% RA (with 2 % bitumen content), 50% RA and 50% G2 Hornfels crushed stone (with 2.1% bitumen content) and 100% G2 (with 2.3 % bitumen content). Tri-axial testing was carried out to determine shear parameters, resilient modulus and permanent deformation behaviour, while brushing testing was carried out to determine the possible durability performance of the BSMs. The mixture durability in terms of moisture damage was investigated. Temperature data were collected and a model to accurately simulate the temperature distribution in the BSMs was identified and proposed for further investigation and validation. It was found from the laboratory temperature data collected in this study that the temperature gradient varied according to the depth of the BSMs. A considerable part of the efforts of this study were dedicated to characterise and model the temperature distribution in a pavement section, taking into account the mechanical properties and performance of the BSMs at different temperature layers. The study provides an insight into fundamental mechanical performance, material durability properties, and the thermal capacity and conductivity of the BSM-foam mixes with high percentage of RA. This will assist in improving the current procedure for selection, combining and formulation of the mix matrices for BSMs. In addition, the study provides guidelines that will enable practitioners to confidently understand the relationship between temperature gradient and mechanical behaviours of BSM-foam pavement section. The specific durability-related issues addressed in this study are substance for future research.
AFRIKAANSE OPSOMMING: Die toenemende gebruik van herwonne asfalt (Engels: reclaimed asphalt (RA)) in bitumen gestabiliseerde materiaal (Engels: Bitumen Stabilised Materials (BSMs)), tekortkominge in die bestaande ontwerpriglyne- en handleidings en deurlopende verbeteringe in die konsepte en begrip van hierdie material vereis verdere navorsing oor die fundamentele eienskappe en gedrag van BSM. In die literatuurstudie word die huidige stand van kennis van die ontwerp van skuimbitumentegnieke ondersoek. Die literatuurstudie dek ook die huidige beste praktyke in die ontwerp van BSM en plaveisels wat hierdie materiale insluit. Tekortkominge en areas van verdere verbetering in die ontwerppraktyke is geïdentifiseer. Onlangse omgewingswetgewing verhoog die belangrikheid van BSM tegnologie, insluitend RA, as ‘n meer omgewingsvriendelike en volhoubare konstruksie-tegniek. Hierdie faktor sal in die toekoms al hoe belangriker word. Die verandering in die gedrag van materiaal en die falingsmeganismes van BSM mengsels is langtermynverskynsels. Dit impliseer dat die studie van die fisio-chemiese en meganiese eienskappe van mengsels met toenemende verhoudings van RA van kardinale belang is’n Fundamentele begrip van die vogskade en temo-fisiese eienskappe, wat verwant is aan die materiale se eienskappe, word vereis. Die primêre doelwit van die studie is die bevordering van BSM tegnologie deur die invloed van die geselekteerde materiale op duursaamheid, temperatuurverspreiding en langtermyn gedrag in al die fases van toepassing (mengselontwerp, konstruksie en in-dienstoestand) te bepaal. Die verhandeling begin met ‘n omvattende literatuuroorsig van navorsing oor die interaksie tussen RA en mineraalaggregate. Die eienskappe van RA en die mineraalaggregate word bespreek. Dit word gevolg deur ‘n oorsig van die meganiese eienskappe van die BSM-skuimbitumenmengsels met ‘n hoë persentasie RA en die duursaamheidgedrag daarvan. Faktore wat die temperatuurgradient van BSM beïnvloed word dan aangetoon. ‘n Beter begrip van die fundamentele gedragseienskappe en die invloed van temperatuur op die gedrag van BSM met ‘n hoë persentasie RA is een van die sleutelfaktore van hierdie navorsing. Dit het ten doel om die uitgebreide kennis te gebruik om huidige mengselontwerp en strukturele ontwerppraktyke te verbeter. Laastens is die fundamentele teorie van termogeleiding en die meganiese eienskappe van BSM gebruik om ‘n verhouding tussen temperature en meganiese eienskappe in ‘n plaveiselsnit te ontwikkel. ‘n Laboratoriumtoetsprogram is opgestel om die eienskappe en gedrag van BSM te bestudeer en om verwantskappe tussen samestellende faktore soos die tipe bindmiddel gebruik, die persentasie RA in die mengsel en die toediening van klein hoeveelhede sement as aktiewe vuller te bepaal. BSM is in drie verskillende verhoudings van RA en goeie gehalte gebreekte klipmateriaal vermeng: 100% RA met 2 % bitumen, 50% RA en 50 % G2 Hornfels gebreekte klip met 2.1 % bitumen en 100% G2 met 2.3 % bitumen. Drie-assige druktoetse is gebruik om skuifsterkteparameters, elastiese modulus en permanente vervormingsgedrag te bepaal. Borseltoetse is gebruik om die duursaamheidgedrag van BSM te bepaal. Die mengsels se duursaamheid is ook in terme van vogskade ondersoek.
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Earnhart, Nicholas Edmond. "Modeling and validation of a syntactic foam lining for noise control devices for fluid power systems." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/50151.
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Excessive fluid-borne noise in hydraulic systems is a problem the fluid power industry has long struggled to address. Traditional noise control devices such as Helmholtz resonators, tuning coils, and Herschel-Quincke tubes are generally too large for fluid power systems unless the speed of sound in the device can be reduced. A compliant lining can achieve this effect, but compliance (and lossy compliance) has had little attention in noise control in general, and in fluid power in particular. One means to achieve compliance in these devices, especially at elevated pressures, is through a liner made of syntactic foam, which in this case is a urethane host matrix with embedded hollow, polymer microspheres. The material properties at elevated pressure are unknown by the liner manufacturer, but are known to be pressure- and temperature-dependent. Therefore, the effect of hydrostatic pressures from 2.1-21 MPa and temperatures from 20-45 C on the liner properties, thus the device performance, are studied. For a Helmholtz resonator, a theoretical model is fit to experimentally-measured transmission loss of the device using a least-squares routine, which solves the inverse problem for the complex bulk modulus of the liner. These material properties are used to compare a predictive model of a tuning coil to experimental data, and in a parameter study of a Herschel-Quincke tube. The compliance of the liner is found to lower the effective sound speed by an order of magnitude and decrease the volume of the cavity of a Helmholtz resonator by up to two orders of magnitude. This work is expected to result is more compact noise control devices for fluid power systems.
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Blandin, Christopher. "Production of dielectric materials." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26568.
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Thesis (M. S.)--Mechanical Engineering, Georgia Institute of Technology, 2009.Committee Chair: Colton, Jonathan; Committee Member: Schultz, John; Committee Member: Zhou, Min. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Chitela, Yuvaraj R. "Sustainable Ecofriendly Insulation Foams for Disaster Relief Housing." Thesis, University of North Texas, 2017. https://digital.library.unt.edu/ark:/67531/metadc984180/.
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Natural disasters are affecting a significant number of people around the world. Sheltering is the first step in post-disaster activities towards the normalization of the affected people's lives. Temporary housing is being used in these cases until the construction of permanent houses are done. Disposal of temporary housing after use is leading to a significant environmental impact because most of them are filled with thermally insulative polymer foams that do not degrade in a short period. To reduce these problems this work proposes to use foams made with compostable thermoplastic polylactic acid (PLA) and degradable kenaf core as filler materials; these foams are made using CO2 as blowing agent for insulation purposes.
Foams with PLA and 5%, 10% and 15% kenaf core were tested. Different properties and their relations were examined using differential scanning calorimetry (DSC), thermal conductivity, mechanical properties, scanning electron microscopy (SEM), x-ray μ-computed tomography (μ-CT) and building energy simulations were done using Energy Plus by NREL. The results show that mechanical properties are reduced with the introduction of kenaf core reinforcement while thermal conductivity display a noticeable improvement.
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Yüksel, Sinan Güden Mustafa. "Crushing behaviour of aluminum foam-filled composite tubes/." s.l.]: [s.n.], 2005. http://library.iyte.edu.tr/tezler/master/makinamuh/T000380.pdf.
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Thesis (Master)--İzmir Institute of Technology, İzmir, 2005.Keywords:crushing, aluminum foam, foam filling, energy absorber, composite tubes. Includes bibliographical references (leaves. 93-96).
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Akar, Egemen Güden Mustafa. "Processing and mechanical testing of Ti6A14V foams for hard tissue implant applications/Egemen Akar; thesis advisor Mustafa Güden." [s.l.]: [s.n.], 2005. http://library.iyte.edu.tr/tezler/master/makinamuh/T000335.pdf.
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Kasichainula, Nagesh. "Mechanic characterization of reinforced rigid polyurethane foams /." free to MU campus, to others for purchase, 2003. http://wwwlib.umi.com/cr/mo/fullcit?p1418038.
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Gerceker, Bora. "Drop Test Simulation Of A Munition With Foams And Parametric Study On Foam Geometry And Material." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12615142/index.pdf.
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Unintentional drop of munitions could be encountered during the storage, transportation, and loading processes. In such an impact, malfunctioning of crucial components of munitions is the worst scenario that may be encountered and level of loads should not reach to critical levels. From two possible methods, experimental one is not frequently applied owing to high cost of money and time. On the contrary, particularly in last couple of years, interest is shifted to numerical simulations such as finite element method.
In this thesis, foam materials will be investigated as energy absorbers to reduce the effect of loads during the impact. However, modeling the behavior of foam materials by FE codes is a challenging task. In other words, more than a few material parameters which are not commonly specified in literature are sufficient to represent the behavior of foams in an appropriate way. For this reason, material characteristics of the selected two foam materials, expanded polypropylene and
v
polyethylene, have been obtained in this study. Characterization of EPP and PE is followed by the selection of the appropriate material models in LS-DYNA which is a nonlinear explicit finite element code.
Drop tests of munitions on which initially specified foam materials are integrated were done to identify the load levels. Validation of drop tests which are explained in detail in this thesis has been accomplished by LS-DYNA. Final section of the thesis is related to optimization of the foam geometry which will provide reducing load levels to allowable limits. After optimization studies, three alternative geometries which succeed in to reduce loads to allowable load levels were reached. Finally, one of three alternatives is selected considering cost and manufacturing difficulties.
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Li, Yuan. "Synthesis and mechanical characterization of transversely isotropic nanoporous platinum." Thesis, Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/42927.
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Nanoporous (NP) metal foams combine desirable characteristics of metals with unique nanoarchitectural features to yield weight normalized properties far superior than either dense metals or bulk metal foams. Due to their high surface to volume ratios these structures show great promise as components of fuel cells, as sensors and have been suggested for use in biological applications, for example as antimicrobial scaffolds or as platforms on which to explore biological material behavior. While most NP metal foams are isotropic, structures with anisotropic features spanning different length scales can further extend applications. This work examines the parameters controlling the synthesis of transversely isotropic NP Platinum foam by dealloying an amorphous Pt-Si alloy. The structure that is examined in this work is hierarchical with Voronoi polyhedra that form on the free surface and under each polyhedral hyper-structure, nanocrystalline NP Pt foam forms with radial struts of length ~60 nm and grain size of 5 nm. The size of the polyhedra can be tailored by changing the dealloying potential. In turn, the mechanical properties of these structures as assessed by nanoindentation can range from 1 to 3GPa depending on the geometric arrangement of the struts. Finally, the initiation location of these structures and the relationship between electrochemical parameters and dealloying front evolution is examined.
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Cano, Camilo I. "Polyimide Microstructures From Powdered Precursors: Phenomenological and Parametric Studies on Particle Inflation." Akron, OH : University of Akron, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=akron1123710711.
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Dissertation (Ph.D.)--University of Akron, Dept. of Polymer Engineering, 2005."August, 2005." Title from electronic dissertation title page (viewed 09/24/2005) Includes bibliographical references.
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Nagel, Adam Richard. "Closed cell steel foams from oxide reduction." Thesis, Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/19569.
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Echard, Dalton. "Drying Methods for the Fabrication of Polymer Foam Material." VCU Scholars Compass, 2016. http://scholarscompass.vcu.edu/etd/4096.
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This is a report on the study of the drying of nanoporous polymer foam material fabricated by photolithogtaphic methods. Three drying methods were employed, which were air drying, supercritical drying and freeze drying. After fabrication and drying, physical properties of the polymer foams were measured. These measurements included density of the material, Young’s modulus, surface area, and the shape of the skeletal particles. The measurements determined the effect of the polymer concentration and the effect of drying methods. It was determined that polymer concentration had a much larger effect on the properties of the materials than the drying method.
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Mikulica, Karel. "Porovnání technických vlastností a technologií pokládky lehkých stavebních hmot pro podlahové konstrukce." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2015. http://www.nusl.cz/ntk/nusl-227536.
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This graduation thesis is aimed to presentation heat isolation materials for the floor constructions. The experimental part is devoted physical - mechanical properties suggested very light concretes with the cement. The main part of the thesis is devoted to form of the transit and putting of the individual heat isolation materials. In the end are suggested structures of the floor constructions with the respect to their properties and price.
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Huang, Jong-Shin. "Foam core materials for structural sandwich panels." Thesis, Massachusetts Institute of Technology, 1991. http://hdl.handle.net/1721.1/13902.
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Masanja, Daniel. "Foam concrete as a structural material /." Stockholm, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4002.
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Kader, Atef Abd El. "Experimental studies of two dimensional foam." Thesis, Queen's University Belfast, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.268219.
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Druma, Adriana M. "Analysis of carbon foams by finite element method." Ohio : Ohio University, 2005. http://www.ohiolink.edu/etd/view.cgi?ohiou1177611967.
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Alcazar, Jorba Daniel. "Liquid foams of graphene." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/75842.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2012.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student submitted PDF version of thesis.
Includes bibliographical references (p. 207-216).
Liquid foams are dispersions of bubbles in a liquid. Bubbles are stabilized by foaming agents that position at the interface between the gas and the liquid. Most foaming agents, such as the commonly used sodium dodecylsulfate, are surfactant molecules with linear or branched chain molecular structures. This thesis presents a new class of liquid foams made with a foaming agent having a sheet molecular structure. In these foams, air bubbles are encapsulated inside graphene shells. The shells have a concentric layered structure made of isophorone diamine modified graphene oxide sheets. The liquid foams of graphene were initially developed as an extractive step in the preparation of graphene-epoxy nanocomposites. Chapter 1 gives an introduction to polymer nanocomposites and graphene. Chapter 2 presents a novel processing method for graphene-epoxy nanocomposites. Chapter 3 deals with the structure, formation mechanism, stability and mechanical properties of the liquid foams of graphene. Chapter 4 reports on materials and methods. Finally, Chapter 5 summarizes the main conclusions of this work and proposes future directions for research.
by Daniel Alcazar Jorba.
Ph.D.
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Rodeheaver, Bret Alan. "Open-celled microcellular themoplastic foam." Thesis, Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/18914.
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Ahmadi, Hoda. "Cellulose-Mycelia foam : novel bio-composite material." Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/59970.
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Demand for sustainable products is growing faster than ever before. Because of this, the development of novel sustainable materials is crucial to leverage our environmental resources and to ensure future growth of Canada's economy. In this study, we propose a technology to develop the use of fungal mycelium, the vegetative part of a fungus, through a porous scaffold of cellulose-based foam. A methodology for producing cellulose-mycelia foam (CMF) has been developed by mixing a surfactant with pulp suspension of 1% consistency and Pleurotus djamor spawn, mixing at high velocity to entrain air, filtering the suspension, and then holding at incubation conditions suitable for mycelium growth. During the incubation period, temperature (20-25 °C), pH (5-8), humidity (80-100%), ventilation and exposure to light were controlled. Simplicity of production, biodegradability, and 3-D porous structure of the product position this biocomposite as a green alternative to polymeric foams. The structure of the CMF was characterized through fluorescent microscopy during the incubation period. The effect of mycelial growth on the mechanical behavior of the CMF including compressibility, thermal decomposition, dry and wet strength was investigated during 25 days of mycelial growth. The results indicated that all tested mechanical properties improved after 25 days of mycelial growth. The second set of experiments was run to specify the application of the CMF in a hydraulic filtration system. The pressure drop, permeability, and filtration efficiency of the product were studied. The experimental results showed that the permeability of the CMF decreases by an increase in mycelial growth. The hydraulic filtration efficiency of the product improved from 74% for cellulosic foam to 99.9% for 25 days CMF for removing 20 µm and larger particles. Bioremediation tests also were performed to evaluate the detoxification capability of mycelia in the CMF. Detoxification tests demonstrated that the living mycelia are able to detoxify potassium hydroxide from waste alkaline batteries.Applied Science, Faculty of
Graduate
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Rožėnas, Paulius. "Putų cementbetonio savybių tyrimas." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2008. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2008~D_20080722_132553-98463.
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Šio magistrantūros studijų baigiamojo darbo tikslas yra išnagrinėti autoklavinio poringojo betono savybes į kurio mišinio sudėtį dedama akytojo betono gamybos atliekų. Akyta cementbetonio struktūra sudaryta naudojant putas. Darbas susideda iš teorinės ir eksperimentinės dalių. Teorinėje dalyje atlikta literatūros analizė, pateiktos bendrosios žinios apie akytuosius betonus, jų žaliavas, klasifikaciją bei kai kurias fizikines ir mechanines savybes. Autoklavinis putų cementbetonis nagrinėjamas kaip viena iš akytojo betono atmainų. Nagrinėjami putokšliai, lyginamos iš jų išplaktų putų savybės. Aptariamas akyto betono atliekų panaudojimas gaminant putų cementbetonį. Šiuo tikslu buvo nagrinėjami įvairūs literatūros šaltiniai, lyginamos įvairių autorių sukauptos žinios ir tyrimų rezultatai. Eksperimentinėje dalyje tiriamos putokšlių ir iš jų išplaktų putų savybės. Nagrinėjamas akytojo betono gamybos atliekų panaudojimas. Aprašoma putų ir betono atliekų kiekio įtaka putų cementbetonio tankiui, gniuždomajam stipriui ir gaminių struktūrai.The point of this postgraduate studies final work is research the autoclaved porous concrete characteristics, in whose composition is waste of porous concreat. The porous structure is make by foam. This work consists of theoretical and experimental parts. The teoretical part of this work consist of literature analysis, there are given general knowledge about porous concrete, materials, classifications, physical and mechanical characteristics. The autoclaved foam cement concrete was researched like one of the active concrete species. There were analysed foamers, comparables internals of foams. Considerating the waste of porous concreat utilization maiking foam cement concrete. For this purpose were researched various information publikations, compared the cumulated knowledges and experimental results of various authors. In experimental part are described foamers and from their mades foams characteristics. Reserching the waste of porous concreat utilization. Described quantity of foams and concrete wastes influence to density, strength and composition of foam cement concrete.
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Gabbrielli, Ruggero. "Foam geometry and structural design of porous material." Thesis, University of Bath, 2009. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.507759.
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Jamshidi, Mohammadsadegh. "A process for recycling thermosetting foams and the incorporation of recycled foams into structural composite panels." Thesis, Queen Mary, University of London, 2009. http://qmro.qmul.ac.uk/xmlui/handle/123456789/581.
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In Europe, the rapidly growing thermosetting foam insulation products industry comprises over 11,500 companies employing over a third of a million people and is worth about 6 billion Euros in trade. It is currently estimated 4-7 % of total new UK production is scrapped and goes to landfill. Estimated costs of disposing of this waste foam are of the order of £20 million/annum to the producers of foam panels and insulation blocks. A new strategic direction for rigid polymeric foams waste management has been developed converting the scrapped thermosetting foams into high added value material that can be used in various applications such as fire resistant insulating applications. Thus by this new innovative recycling process the waste is not only eliminated but benefits can be gained from the new material that comes out of it as a structural composite panel. The project involves a new concept that mixes fragmented scrap thermosetting foams materials with a proprietary liquid that cures at ambient temperature to form an incombustible material capable of withstanding high temperatures >1000 C. In this research different kind of polymeric foams used for manufacturing of reconstituted recycled samples. Sodium silicate solution has been chosen as the binder to binds shredded foams together. Due to fastening of sodium silicate curing different kind of acidic powders have been tested. For increasing of post properties after curing variety of fillers as an additive have been tried through out this research. Different foam cutting methods have been tested to find the suitable shredding routine. Rationale for selection of generic binder and its hardeners/fillers has been discussed in this project. Also as post properties evaluation compressive strength, thermal resistance, fire resistance and acoustic properties of recycled structural composite panels have been measured. At last a model for thermal conductivity of composite panels is developed.
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Carnachan, Ross James. "Emulsion-derived (PolyHIPE) foams for structural materials applications." Thesis, Durham University, 2004. http://etheses.dur.ac.uk/3672/.
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The simplest type of sandwich composite consists of two, thin, stiff strong sheets of dense material separated by a thick layer of low density material. The first major structure to incorporate sandwich panels was the Second World War "Mosquito aircraft" which consisted of a balsa wood core with plywood faces. The cellular materials used for sandwich core applications can generally be divided into two categories; honeycomb structures and polymer foams. Other cellular cores which exist are balsa wood and corrugated cores. Honeycomb materials generally have a hexagonal cellular shape, and are the core material of choice for advanced composites, In this thesis it was the aim to prepare open-cellular PolyHIPE foam core materials by the polymerisation of the continuous phase of a high internal phase emulsion (HIRE). To assess whether PolyHIPE materials are viable as core materials their flexural, compressive and shear properties were evaluated against the current commercially used core materials. It was shown that it was possible to improve the flexural, compressive and shear properties of a styrene/DVB PolyHIPE material by the addition of fibres to the material and the use of an optimised surfactant system (OSS). It was also shown that by the addition of monomers such as; butyl acrylate, 2-ethylhexyl acrylate, butyl methacrylate and methyl methacrylate to the monomer phase that the compressive properties of the S/DVB material could be varied. It was also possible to prepare a fibre-free and fibre-reinforced resorcinol- formaldehyde-based material, which had greater compressive and shear properties compared to the styrene/DVB material. Also a PolyHIPE material containing poly (ϵ-caprolactone) diacrylate showed shape-memory properties and an elongated cell structure after deformation and cooling. This elongated cell structure could lead to possible anisotropic behaviour. Finally it was concluded that the best mechanically performing PolyHIPE materials prepared competed well with the shear and compressive strength of the commercial honeycomb and foam core materials examined.
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Siegkas, Petros. "Static and dynamic performance of Ti foams." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:68938d12-d104-4637-8b08-d1c126ddca84.
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Titanium (Ti) foams of different densities 1622-4100 Kgm-3 made by a powder sintering technique were studied as to their structural and mechanical properties. The foams were tested under static and dynamic loading. The material was tested quasi statically and dynamically under strain rates in the range of 0.001-2500 s-1 and under different loading modes. It was found that strain rate sensitivity is more pronounced in lower density foams. Experiments were complimented by virtual testing. Based on the Voronoi tessellations a computational method was developed to generate stochastic foam geometries. Statistical control was applied to produce geometries with the microstructural characteristics of the tested material. The generated structures were numerically tested under different loading modes and strain rates. Voronoi polyhedrals were used to form the porosity network of the open cell foams. The virtually generated foams replicated the geometrical features of the experimentally tested material. Meshes for finite element simulations were produced. Existing material models were used for the parent material behaviour (sintered Ti) and calibrated to experiments. The virtual foam geometries of different densities were numerically tested quasi statically under uniaxial, biaxial and triaxial loading modes in order to investigate their macroscopic behaviour. Dynamic loading was also applied for compression. Strain rate sensitive and insensitive models were used for the parent material model in order to examine the influence of geometry and material strain rate sensitivity under high rates of deformation. It was found that inertial effects can enhance the strain rate sensitivity for low density foams and numerical predictions for the generated foam geometries were in very good agreement with experimental results. Power laws were established in scaling material properties with density. The study includes: 1. Information on the material behaviour and data for macroscopically modelling this type of foams for a range of densities and under different strain rates. 2. A proposed method for virtually generating foam geometries at a microscopic scale and examine the effect of geometrical characteristics on the macroscopic behaviour of foams.
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Gu, Zipeng. "Emulsion Templated Polyimide Aerogel Foam and Hybrid Aerogel Foam as Absorbents for Oil Cleanup." University of Akron / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron1525711842824095.
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Shen, Jiong. "Application of nanoparticles in polymeric foams." Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1150139899.
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Bo, Chong. "Nanohybrids Based on Solid and Foam Polyurethanes." Thesis, University of North Texas, 2015. https://digital.library.unt.edu/ark:/67531/metadc799520/.
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Polymer nanocomposites are a going part of Materials Science and Engineering. These new composite materials exhibit dimensional and thermal stability of inorganic materials and toughness and dielectric properties of polymers. Development of nanocomposites become an important approach to create high-performance composite materials. In this study silica, fly ash, silica nanotubes and carbon black particles have been added to modify polyurethane foam and thermoplastic polyurethanes. It has been found that the addition of silica can diminish the size of foam bubbles, resulting in an increased stiffness of the material, increase of the compressive strength, and greater resistance to deformation. However, the uniformity of bubbles is reduced, resulting in increased friction of the material. Fly ash added to the foam can make bubbles smaller and improve uniformity of cells. Therefore, the material stiffness and compressive strength, resistance to deformation, and has little impact on the dynamic friction of the material. Adding nanotubes make bubble size unequal, and the arrangement of the bubble uneven, resulting in decreased strength of the material, while the friction increases. After the addition of carbon black to the polyurethane foam, due to the special surface structure of the carbon black, the foam generates more bubbles during the foaming process changing the foam structure. Therefore, the material becomes soft, we obtain a flexible polyurethane foam. The results of mechanical properties determination of the thermoplastic polyurethane that adding particles may increase the stiffness and wear resistance of the thermoplastic polyurethane, while the tensile properties of the material are reduced. This phenomenon may be due to agglomeration of particles during the mixing process. Possibly the particles cannot be uniformly dispersed in the thermoplastic polyurethane.
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Ribeiro-Ayeh, Steven. "Finite element modelling of the mechanics of solid foam materials." Doctoral thesis, Stockholm, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-154.
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Curran, David Charles. "Aluminium foam production using calcium carbonate as a foaming agent." Thesis, University of Cambridge, 2004. https://www.repository.cam.ac.uk/handle/1810/252945.
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The current state of the art with regards to the production of metallic foams is reviewed, with melt-based processes identified as the most promising for cost-effective large-scale production. The potential for metal carbonates as an alternative to currently-used titanium hydride foaming agents is explored, with calcium carbonate identified as the most suitable. The influence of a range of material and processing parameters on the stability of metallic foams in the molten state is discussed, and current methods of controlling melt viscosity and surface tension are reviewed. Characteristic features of the compressive deformation of metallic foams are described in the context of use as an impact-absorbing material, with a review of work in the literature linking the bulk mechanical properties to details of the cell structure. Calcium carbonate is found to be a highly effective foaming agent for aluminium. The foams obtained have notably finer cell structures than can be achieved in foams produced with titanium hydride, coupled with enhanced stability in the molten state. This is attributed to the presence of a thin continuous surface film of metallic oxide that counteracts the effect of surface tension. This film, combined with the finer cell structure of the calcium carbonate-based foams, is found to significantly reduce the rate of gravity drainage of the melt. The formation of the thin oxide film during foaming gives rise to a number of artefacts on the cell surface, including stretch marks and tear bands. A range of chemical and surface analysis techniques are used to identify the chemical composition and thickness of the oxide film. The distribution of refractory particles in the cell faces, which are commonly employed to stabilise molten foam structures, is found to be highly non-uniform in foams which undergo significant gravity drainage of liquid metal during the foaming process. Experiments in which the concentration of particles is varied demonstrate the importance of their effect on the melt viscosity in addition to their known role as a surface stabilising phase. The effect of alloy content and foaming gas on the stability of standing molten foams is also investigated in the context of other foaming processes. The formation of an oxide film on the surface of the cells is shown thermodynamically to be a necessary step in the production of low-density aluminium foams with a calcium carbonate foaming agent. A temperature-dependent upper limit on porosity is observed. It is established that this is the result of inhibition of the calcium carbonate decomposition reaction by its products as the thickness of the surface oxide film increases. The effect of varying cell size, porosity and chemical composition on the thickness of the surface oxide film is derived. The rate of thermal decomposition of calcium carbonate is found to be dominated by the partial pressure of carbon dioxide, with particle size and small impurity contents having only a small effect. Compressive mechanical properties of the foams produced are compared with those of foams produced with a titanium hydride foaming agent and theoretical predictions. A reduced cell size apparently minimises the influence of point defects on the properties of specimens of finite dimensions. A significant difference in the shape of the stress-strain curves of calcium carbonate- and titanium hydride-based foams is noted, with the latter marked by extensive serrations. This difference is demonstrated to be independent of differences in cell size. Microstructural analysis of foams in various stages of failure suggests that this is due to differences in the distribution of refractory particles in the two foams, which is in turn a consequence of the reduced extent of gravity drainage of liquid metal in the calcium carbonate-based foams.
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Mullarkey, Peter Gerard. "The modelling of variable geometry honeycombs and foam." Thesis, University of Exeter, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.341164.
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Claus, Julien. "Investigations on a new high-strength pozzolan foam material." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/31804.
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Thesis (M. S.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2009.Committee Chair: Doyoyo Mulalo; Committee Member: Will Kenneth; Committee Member: Yavari Arash. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Embrey, Leslie. "Three-Dimensional Graphene Foam Reinforced Epoxy Composites." FIU Digital Commons, 2017. http://digitalcommons.fiu.edu/etd/3128.
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Three-dimensional graphene foam (3D GrF) is an interconnected, porous structure of graphene sheets with excellent mechanical, electrical and thermal properties, making it a candidate reinforcement for polymer matrices. GrF’s 3D structure eliminates nanoparticle agglomeration and provides seamless pathways for electron travel. The objective of this work is to fabricate low density GrF reinforced epoxy composites with superior mechanical and electrical properties and study the underlying deformation mechanisms. Dip coating and mold casting fabrication methods are employed in order to tailor the microstructure and properties. The composite’s microstructure revealed good interfacial interaction. By adding mere 0.63 wt.% GrF, flexural strength was improved by 56%. The addition of 2 wt.% GrF showed a surge in glass transition temperature (56oC), improvement in damping behavior (150%), and electrical conductivity 11 orders of magnitude higher than pure epoxy. Dip coated and mold casted composites showed a gauge factor of ~2.4 indicating electromechanically robust composite materials.
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Clancy, Richard Brian. "Properties and fabrication of hollow sphere nickel foams." Thesis, Georgia Institute of Technology, 1992. http://hdl.handle.net/1853/9333.
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Styles, Millicent. "Characterisation of the flexural behaviour of aluminium foam composite sandwich structures /." View thesis entry in Australian Digital Theses Program, 2008. http://thesis.anu.edu.au/public/adt-ANU20080813.170807/index.html.
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Clark, Laura A. "Investigation and Optimization of a Porous Sintered Ceramic Material in a Grinding Application." Digital WPI, 2009. https://digitalcommons.wpi.edu/etd-theses/675.
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Porous sintered ceramic foam made of 99.8% Alumina (AL2O3) was investigated for grinding applications in metallic bearings. The properties of this alumina foam were investigated and correlated to the grinding performance in an I.D. grinding application. The mechanical properties, such as density and Young's Modulus, were correlated to grinding performance. The physical properties, investigated with Scanning Electron Microscope (SEM) analysis and a CT Scan, were used to study sintering behavior and porosity size and distribution. This work found an optimal friability and sintering temperature for the alumina foam grinding wheels. This will enable the alumina foam to become a viable grinding product and compete with the conventional vitrified products. This would be significant since the alumina foam has mainly one ingredient and is manufactured with a simpler process. It can also support a higher porosity than conventional grinding wheels, which has proven to provide better grinding performance and coolant access, keeping the work piece cooler and avoiding thermal damage.
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Zhong, Chong. "Pressure Chamber Experiments to Determine Triaxial Material Properties of Polymer Foams." University of Akron / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=akron1556265641540063.
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Fu, Jin. "Development of polymeric foam materials with improved mechanical and acoustic properties." Thesis, University of Ottawa (Canada), 2005. http://hdl.handle.net/10393/26905.
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This thesis addresses the processing, morphology, mechanical properties, and acoustic properties of new polymeric foam materials. A batch foaming process, a rotational mold foaming process and a constrained mold foaming process were designed and applied in the producing of polymeric foams. Microcellular closed cell polymethyl-methacrylate (PMMA) foams were produced using the batch foaming process. The foam morphologies and mechanical properties such as elastic modulus, tensile strength and elongation at break were investigated by varying the foaming parameters. The PMMA microcellular foam showed superior mechanical properties in tensile strength and elongation at break over conventional foams. Nanoclay was used as reinforcement filler and a nucleation agent for PMMA in the batch foaming process. The nanoclay affected the foaming behavior and enhanced the mechanical properties of the microcellular PMMA foams. The PMMA nanocomposite foam with 0.5 wt % nanoclay exhibited optimized mechanical properties. Fine celled Polypropylene (PP) and low density Polyethylene (LDPE) foams were also produced using the rotational mold foaming. The processing parameters such as the particle sizes and processing time were important parameters in this process. The obtained PP foam exhibited a greatly improved energy absorption capacity. Opened cell PMMA foams were produced using a particulate leaching/gas foaming method for acoustic absorption applications. The foam morphology i.e. porosity and cell sizes were independently controlled by altering the processing settings. Consequently, the acoustic performance of the foams was manipulated. Finite element analysis was then employed to predict the macroscopic properties of polymeric foams correlated to their microstructure. The predicted elastic responses of both opened cell and closed cell foams showed great agreement with experimental results.