Mechanical properties of a particle-strengthened polyurethane foam

Abstract

Quasi-static compression tests have been performed on polyurethane foam specimens. The modulus of the foam exhibited a power-law dependence with respect to density of the form: E* ϰ (*) n , where n ϭ 1.7. The modulus data are described well by a simple geometric model (based on the work of Gibson and Ashby) for a closed-cell foam in which the stiffness of the foam is governed by the flexure of the cell struts and cell walls. The compressive strength of the foam is also found to follow a power-law behavior with respect to foam density. In this instance, Euler buckling is used to explain the density dependence. The modulus of the foam was modified by addition of gas-atomized, spherical, aluminum powder. Additions of 30 and 50 wt % Al measurably increased the foam modulus, but without a change in the density dependence. However, there was no observable increase in modulus with 5 and 10 wt % additions of the metal powder. Strength was also increased at high loading fractions of powder. The increase in modulus and strength could be predicted by combining the Gibson-Ashby model, referred to above, with a well-known model describing the effect on modulus of a rigid dispersoid in a compliant matrix.

Evaluation of the anisotropic mechanical properties of reinforced polyurethane foams

“…Numerous studies have reported improvements in the mechanical properties of polymer foams 79 reinforced with short fibers [9,10,11,12,13], particles [14,15,16,17,18], and nano-particles 80 [19,20,21,22], but relatively few have made use of cellular models to interpret the results of 81 mechanical tests and to develop predictive tools. Barma et al [15] related the foam stiffness (E f ) 82 to the solid stiffness (E s ) and cell size in particle-reinforced foams at the same density.…”

High damping property of microcellular polymer prepared by friendly environmental approach

“…The reason is also related to the cell size and its distribution. Smaller cells with relative thicker struts, defined by the cell edges [17], had good elasticity. Larger cells with feathery edges caused more brittle of PU foams.…”

“…12a. Nix and coworkers had defined the wall of a closed cell foam [17]. The wall encloses the cells in the closed-cell foam system.…”

Preparation and characterization of cyanate/epoxy foam

“…The experimental data can be fit with a power law expression with respect to the foam density, 43,44 as follows:…”

“…4,43 Over the range of the density analyzed, a good fit of E and c values is obtained for values of density exponents n and p, which are 1.8 and 2.3, respectively. Goods et al 43 reported the density exponent of 2.10 and 1.70 for c and E, respectively, for the rigid polyurethane foam. They prepared the polyurethane foam with much higher packed density via compression molding technology.…”