Polymer-Solvent Phase Separation as a Route to Low Density,Microcellular Plastic Foams

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Cell sizes for TPX foams are reported here as the largest mean free path distance between wall or rib structures. The numbers are empirical and are determined by observing stereo SEM photomicrographs of large surfaces of the foams, the surfaces being cut by a Vibratome biological sample preparation system (see Reference 9a for representative stereo photomicrographs). Cell size distributions are very difficult to obtain accurately by this method but estimates can be made. For example, 30μm foam has a cell size distribution of about 10-30μm and a 6μm foam has a cell size distribution of about 2-6μm.

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