Preparation of foamed acrylamide polymers

Claim 1

PROCESS FOR THE PRODUCTION OF FOAMED PLASTIC STRUCTURES OF POLYMERS SELECTED FROM THE GROUP CONSISTING OF A HOMOPOLYMER OF ACRYLAMIDE MONOMER AND COPOLYMERS OF ACRYLAMIDE MOMOMER WITH AT MOST 70% BY WEIGHT OF SAID COPOLYMERS OF A MEMBER SELECTED FROM THE GROUP CONSISTING OF ACRYLINITRILE, ACRYLIC ACID, AND STYRENE MONOMER, WHICH COMPRISES POLYMERIZING SAID MONOMERIC MATERIALS AT A POLYMERIZATION TEMPERATURE OF 20*C. TO 110*C. IN AN AQUEOUS POLYMERIZING MEDIUM CONTAINING A PEROXIDIC POLYMERIZATION CATALYST AND ABOUT 0.01 TO 15% BY WEIGHT OF THE WEIGHT OF THE MONOMERS EMPLOYED OF A METAL SALT OF THE GROUP CONSISTING OF THE SULFATES OF IRON, CHROMIUM, VANADATE, TITANIUM AND MANGANESE,AMMONIUM VANADATE AND MANGANESE CARBONATE, THE PH OF SAID AQUEOUS POLYMERIZING MEDIUM BEING WITHIN A RANGE OF FROM NEUTRAL TO THAT OF AN AQUEOUS 60% SULFURIC ACID SOLUTION, WASHING THE POLYMER FORMED FREE OF ANY ACID, DRYING THE POLYMER, MOLDING THE DRIED POLYMER UNDER HEAT AND PRESSURE TO FORM A HOMOGENEOUS MOLTEN SHAPED MASS AND THEN HEATING THE SHAPED MASS OBTAINED TO A TEMPERATURE OF 150*C. TO 240*C. TO FORM A FOAMED PLASTIC STRUCTURE.