The invention concerns a polymer material consisting of macromolecular chains bound by hydrogen bonds wherein: the macromolecular chains consist of a polymer skeleton whereon is fixed by at least one covalent bond a modifying agent, the modifying agent comprising, assembled in a common molecule, one or more associative groups capable of being bound by hydrogen bonds and one or more reactive groups capable of forming covalent bonds with the polymer skeleton, at least one of the associative groups of the modifying agent is an imidazolidone heterocycle, the macromolecular chains bear on average 1 to 10 imidazolidone groups per chain. The average number of imidazolidone groups to be introduced into the macromolecular chains depends both on the average mass of said chains and the final properties desired for the material. The inventive polymer material can be extruded, co-extruded, injected, blown, moulded, overmoulded, calandered, thermoformed. It can be used to produce articles such as tubes, films, plates, extruded strings, bottles, containers. The inventive polymer material can also be mixed with other materials such as other polymers, thus it is used for example as impact modifier or rheology regulator. The invention further concerns the use of said polymer material as compatibility agent in a composition comprising among others at least two polymers belonging to different classes of polymers.