Abstract: Copolymers which are obtainable by reacting acrylic monomers with monomers of the following formula:R.sub.4 --O--R.sub.5 --CO--NH--R.sub.6wherein R.sub.4 represents H or a group of the following formulae: ##STR1## R.sub.5 represents an oxyalkenyl group of the following formulae:--(CHR.sub.1 --CH.sub.2 --O).sub.m -- or --(CHR.sub.1 --CH.sub.2 --O).sub.m1 --(CH.sub.2 --CH.sub.2 --O).sub.n --R.sub.6 represents a C.sub.1 - to C.sub.8 -alkyl group, a C.sub.5 - to C.sub.7 -cycloalkyl group, or a phenyl group. The copolymers are very useful as additives or admixtures for improving the properties of construction materials and of dispersions.