The invention relates to polyurethane foams comprising
(i) ethylenimine, polyethylenimine, polyvinylamine, polyvinylamine
copolymers, carboxymethylated polyethylenimines, phosphonomethylated
polyethylenimines, quarternized polyethylenimines and/or
dithiocarbamatized polyethylenimines or
(ii) alkali hydroxides and/or alkaline earth metal hydroxides or
a mixture consisting of both (i) and (ii).
