METHOD FOR PRODUCING AQUEOUS SOLUTIONS OF POLYACRYLIC ACID WITH A REDUCED CONTENT OF ACRYLIC ACID Russian patent published in 2023 - IPC C08F20/06 C08F2/10 

FIELD: chemistry and technology of polymers.

SUBSTANCE: invention relates to a method for producing polyacrylic acid in the form of a solution. A method for obtaining aqueous solutions of polyacrylic acid with a reduced content of acrylic acid is carried out by radical polymerization of acrylic acid in the presence of an initiator of ammonium or potassium persulfate in an amount of 1.7-2.3 wt.% relative to the monomer at a temperature of 80-95°C, the synthesis is carried out in a mixture of water and aliphatic alcohol C2-C3, with an alcohol content of 2.0-16.0 wt.% of the amount of water, and upon completion of polymerization, the aliphatic alcohol is removed by azeotropic distillation, which ensures the production of a polymer with a molecular weight of not more than 180,000 and low residual monomer content of not more than 0.001 wt.%.

EFFECT: producing an aqueous solution of polyacrylic acid with a molecular weight of not more than 150,000-180,000 and with a low content of residual acrylic acid (not more than 0.001 wt.%), and with high optical performance without the use of toxic molecular weight regulators.

2 cl, 1 tbl, 16 ex