PROCESS FOR PREPARATION OF POLYTHIOETHERSULPHIDE Russian patent published in 2018 - IPC C08G75/16 

FIELD: technological processes.

SUBSTANCE: present invention relates to a process for the preparation of a liquid polymer with terminal mercaptan groups of formula (I): HS-R-(S_y-R)_t-SH (I), in which each R is independently selected from branched alkanediyl or branched arenediyl groups having the structure -(CH₂)_p-O-(CH₂)_q-O-(CH₂)_r- and in which 0–20 % of the number of R groups in the polymer are branched alkanediyl or branched arenediyl groups and 80–100 % of the number of R groups in the polymer have a structure -(CH₂)_p-O-(CH₂)_q-O-(CH₂)_r-, in which t has a value in the range of 1–60, y is an average value in the range of 1.0 to 1.5, q is an integer in the range 1–8, and p and r are integers in the range 1–10, said process comprising steps of: a) forming a polymer by reacting a bis(haloalkyl)formal with an alkali metal polysulphide of the formula M₂S_x, in which M is an alkali metal and x is an average value in the range of 1.04–1.8, b) reacting said polymer with a reducing agent in an aqueous reaction mixture with reductive splitting of polysulphide bonds, and c) lowering the pH of the mixture obtained in step b) to below 6.0 by adding an acid.

EFFECT: producing a polymer having an improved ability to restore its original shape after being released from deforming compression forces and an improved tendency to recover during the application of said forces.

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