A method for obtaining bromine-containing bicyclic unsaturated polyesters by the interaction of 1,4,5,6,7,7-hexabromobicyclo-[2,2,1]-hept-5-ene-2,3-dicarboxylic acid anhydride, propanetriol and maleic anhydride was developed. It was found that unsaturated polyethers synthesized by a two-step method have a higher molecular weight (3130), density (1.461 g/cm³), viscosity (105 St) and ether number (400 ml KOH/g). It was found that the compositions of epoxy resin ED-20 with unsaturated polyether obtained by method III possess higher tensile strength (90 MPa), higher relative elongation (9%), higher Vicat resistance (250⁰C) than unmodified epoxy resin. It was shown that in comparison with pure epoxy resin ED-20, its composition with unsaturated polyester synthesized by method I and cured in the presence of polyethylene polyamine (ED-20: unsaturated polyester: polyethylene polyamine), has flame retardant properties, high tensile strength, higher relative elongation and thermal resistance by Vicat.  The best results are achieved when the content of unsaturated polyester in the composition is 20%

doi.org/10.32737/0005-2531-2023-4-63-70