Preparation of a low density polymer foam with dopants

Low density microcellular foams containing dispersed high atomic number material have been produced. The work done by R. Simandl et al., using phase inversion of a binary solvent system and poly (4-methyl 1-pentene) to produce microporous polymer foams was successfully duplicated. To enhance the diagnostic properties of the material, molybdenum, a high Z material, was dispersed throughout the foam. We have been able to incorporate the molybdenum into the foam structure while maintaining a relatively low bulk density. Foam samples with initial molybdenum concentrations up to 25 wt % and with bulk densities as low as 15 mg/cc have been produced. The uniformity of the molybdenum dispersion has not yet been quantitatively characterized but does vary from sample to sample. 3 refs., 3 figs., 1 tab