Preparation of multishell ICF target plastic foam cushion materials by thermally induced phase inversion processes

Homogeneous, low-density plastic foams for ICF targets have been prepared by thermally induced phase inversion processes. Uniform, open cell foams have been obtained by the rapid freezing of water solutions of modified cellulose polymers with densities in the range of 50--7 mg/cm3 and respective average cell sizes of 2 to 40 μm. In addition, low-density, microcellular foams have been prepared from the hydrocarbon polymer poly(4-methyl-l-pentene) via a similar phase inversion process using homogeneous solutions in organic solvents. These foams have densities from 20 to 50 mg/cm3 and average cell sizes of 20 μm