FIELD: polymer production. SUBSTANCE: invention provides hyperbranched copolyamide, which can be used as viscosity modifier in molten thermoplastic polymer compositions, as modifier of thermomechanical properties of polymer materials, and as additive to thermoplastic fiber-forming matrixes. According to first embodiment of invention, copolyamide is prepared via polycondensation of (i) monomer A-R-Bf wherein A and B represent polymerizable reactive functional groups capable of interacting with each other, R represents hydrocarbon group, and f total number of groups in monomer, f≥2 and preferably 2≤f≤10, and (ii) bifunctional monomer A'-R'-B' or corresponding lactam wherein A', B', and R' have the same designations, which are assigned above to A, B, and R. Molar ratio (i)/(ii) is below 0.05. One of groups R and R' is aliphatic, cycloaliphatic, or arylaliphatic. In monomers (i) and (ii), group A is amine group, B carboxylic group. Monomer (ii) can also be ε-caprolactam. Copolyamide may further contain, as structural motifs, mono- and polyfunctional monomers (iii): core-forming monomer R'(B")n wherein 1≤n≤100 and/or (iv) chain- limiting monomer R2 wherein A", B", R1,R2 have above-indicated designations. According to second embodiment, terminal groups of hyperbranched copolyamide are modified and metal ions are bound using complexation or ion- exchange reactions. EFFECT: allowed stabilizing dispersions of aqueous, organic, and mineral products and modifying surface, hydrophilic/hydrophonic, thermomechanical, and rheological properties of polymeric materials. 21 cl, 4 dwg, 8 tbl, 16 ex
