| abstract |
Process for the preparation of powdery polymers by polymerizing N-vinylcarboxamides, water-soluble esters of ethylenically unsaturated carboxylic acids, N-vinylimidazoles and N-vinylimidazolines and by copolymerizing N-vinylformamide with N-vinylpyrrolidone or vinyl acetate in supercritical carbon dioxide under pressure and mixing in the presence of radicals initiators, 100 to 1500 parts by weight of carbon dioxide being used per 100 parts by weight of monomer. |