abstract |
The crosslinked, porous, pearl-shaped copolymer with 50 to 99.9% by weight of repeating units of a heterocyclic 5-ring compound containing a polymerizable olefinic group, which has at least one protonatable nitrogen atom in the ring, 0.1 to 50% by weight of units of a crosslinking agent up to 25% by weight units of a polymerisable organic boron or silicon compound and, based on 100% by weight of the sum of the aforementioned units, 5 to 350% by weight units of an N-vinyl amide of the general formula I CH 2 = CH -N (R 1 ) -C (R 2 ) = 0, in which R 1 is hydrogen, methyl or ethyl and R 2 is hydrogen or (C 1 -C 3 ) alkyl, or several such N-vinylamides and 0 to 40 % By weight of another polymerizable compound or several such compounds is produced by reverse suspension polymerization and used, for example, as a sorbent for acidic substances from their preferred aqueous solutions. |