Phase diagrams for the systems composed of nitrocellulose and butadiene-nit
rile rubbers with various content of acrylonitrile were obtained by the met
hods of cloud points and static sorption of solvent vapors. The systems stu
died are characterized by their UCST, whose value decreases significantly w
ith an increase in the fraction of polar groups in the rubber. In this case
, the range of polymer compatibility becomes wider.