Foamable polysulphone particles prepn. - with a high yield of particles of dia. above 500 microns

摘要

Blowing agent-.contg. foamable particle-shaped polysulphones are prepd by bead polymerisation of SO2 and alpha-solefin(s) in aq. medium with the addn. of dispersing agents, catalysts sol. in organic solvents, and opt. in the presence of blowing agents which form gas at the polysulphone glass temp. Polymerisation is at 20-80 degrees C with stirring, under excess pressure and in the presence of SO2-alpha-olefine bead polymers with a particles dia. of 500 mu. The polymer beads are prepd. in high yield, with a large amt. having a particle dia. 500 mu and with a mean particle size of 0.5-3 mm. The polymer particles with a dia. 500 mu can, after foaming to discrete beads with a bulk density of 0.2-0.08 g/cm3, be used directly in an insulating material for e.g. heat insulation, for light building material in combination with e.g. gypsum. By fusion or adhesion, foamed shapes for insulation and packing can be obtd.