The Predictive Effects Of Filler Materials On The Mechanical Properties Of Flexible Polyurethane Foam

ABSTRACT

In this study, the use of purely inorganic filler materials to influence the mechanical properties of flexible polyurethane foam has been investigated. The fillers were calcite (CaCO3), dolomite (CaMg(CO))), and kaolin (ALSO(OH)) of volume fractions ranging from 0 - 40 wt%. Each of the filler content ranges was investigated at the following average particle size distributions: 0.06, 0.5, 3.5, 10, 20, and 841 um. The experiment was performed in a discontinuous foaming process based on a completely randomized design of experiment with varying filler types, volume fractions, and particle size distributions to produce reinforced flexible polyurethane foam with the amount of the chemical components chosen to obtain a target density of 25 kg/m? The chemicals (polyol, isocyanate, surfactant, and catalysts) were conditioned to temperatures of between 18 - 22 °C 'and the foams were produced at atmospheric pressure of 760mmHg and relative humidity of 55+ 5 %.

The mechanical properties analyzed from the foam samples collected from the top, middle, and bottom sections of the foam blocks are Indentation Force Deflection quoted at 25, 40, and 65 % Indentations, Tensile Strength, and Elongation-at-Break. Averages of the values obtained from the foam samples are reported for these properties. It was found that flexible polyurethane/filler composite foam with calcite and dolomite as the filler and of particle size distributions of 0.06, 0.5, and 3.5 um showed considerable improvement of mechanical property, specifically in Indentation Force Deflection. The property, however, deteriorated with particle sizes of 10, 20, and 841 um. This observation can be explained by the intercalation of filler particles in the polyurethane foam mass.