Journal ArticleDOI
Load–compression behavior of flexible foams
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TLDR
In this article, it is shown that the load-compression behavior of a flexible polyurethane foam can be factored into the product of two terms: (1) a dimensionless function of the compressive strain, ψ(e), calculated from experimental loadcompression data and reflecting the buckling of the foam matrix; and (2) a factor, eEƒ, where Eƒ is the apparent Young's modulus, which is a function primarily of the modulus of the base polymer E0 and of the volume fraction of polymer,Abstract:
The load-compression behavior of a foam reflects its geometric structure and the physical properties of the matrix polymer. Quantitative relations between these parameters have been established in the present study. Based on both theoretical analyses and experimental data obtained on a flexible polyurethane foam, it is shown that the compressive stress can be factored into the product of two terms: (1) a dimensionless function of the compressive strain, ψ(e), calculated from experimental load-compression data and reflecting the buckling of the foam matrix; and (2) a factor, eEƒ, where Eƒ is the apparent Young's modulus of the foam (which is a function primarily of the modulus of the base polymer E0 and of the volume fraction of polymer, φ). Thus the compressive stress behavior of a foamed polymer is determined by E0, φ, and the matrix geometry, the latter described by the function ψ(e). Using these established relations, it now is possible to delineate precisely the structural features a foam mus...read more
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Journal ArticleDOI
Characterization of polymeric structural foams under compressive impact loading by means of energy-absorption diagram
TL;DR: In this paper, the mechanical properties at room temperature of three polymeric foams (namely EPP, PUR and PS/PA) have been experimentally evaluated in both static and impact loading conditions.
Journal ArticleDOI
Non-linear properties of metallic cellular materials with a negative Poisson's ratio
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TL;DR: Negative Poisson's ratio copper foam was prepared and characterized experimentally as mentioned in this paper, and the transformation into reentrant foam was accomplished by applying sequential permanent compressions above the yield point to achieve a triaxial compression.
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Constitutive modeling of polymeric foam material subjected to dynamic crash loading
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Journal ArticleDOI
Substituting soybean oil-based polyol into polyurethane flexible foams
TL;DR: In this article, flexible polyurethane flexible foams were synthesized by substituting a portion of base polyether polyol with soybean oil-derived polyol (SBOP) as well as well known substituent: crosslinker polyol and styrene acrylonitrile (SAN) copolymer-filled polyol.
Journal ArticleDOI
Macroporous poly(N-isopropyl)acrylamide networks: formation conditions
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