FIELD: chemistry.
SUBSTANCE: disclosed is use of polyamide-based copolymers containing at least one graft side chain consisting of ethylenically unsaturated compounds as an additive for compositions containing hydraulic binding agents, and particularly as water retention agents. Cementing oil and gas wells is of special importance. Typical examples of the polyamide component are natural components, specifically caseins, gelatins, collagens and soya proteins. In applications according to the invention, copolymers which usually have molar mass 
are particularly preferable to those which are water-soluble and biodegradable.
EFFECT: possibility of using polyamide-based copolymers for said purpose even in extreme conditions.
13 cl, 17 ex
