METHOD OF PURIFYING POLYISOBUTYLENE FROM CATALYST TO OBTAIN COAGULANT SOLUTION Russian patent published in 2024 - IPC C08F6/08 

FIELD: chemistry.

SUBSTANCE: present invention relates to a method of purifying polyisobutylene from a catalyst to obtain a coagulant solution, comprising stepwise washing of a polymerisate, characterized by that the polymer solution in hydrocarbons from the group of unreacted olefins, n- and isobutane is treated at the first step with acidified water with pH 1.5–2.9 with subsequent separation into aqueous and organic phases using an acidifying agent with a volume ratio of acidified water and polymerisate of 1:5–25, wherein washing temperature is 10–60 °C at pressure 0.4-1.0 MPa, wherein the organic phase is subjected to successive treatment, namely with 2–5% alkali solution to convert the residual aluminium chloride into sodium aluminate, followed by separation into an aqueous and an organic phase, and then final washing with water from residual sodium aluminate, followed by separation into aqueous and organic phases at a treatment temperature and separation of 10–60 °C, at pressure of 0.4–1.0 MPa, wherein the volume ratio of the alkali solution at the third step to polymerisate is 1:3–15.

EFFECT: obtaining a coagulant solution in order to prevent formation of HCl, Al(OH)₃ from AlCl₃, removal of aluminium chloride from the process without changing its composition and providing the possibility of using the removed aluminium chloride in water treatment and water treatment processes, obtaining a colourless transparent polymer which is practically free of a catalyst.

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