CLEANING METHOD OF POLLUTED POLYMERS Russian patent published in 2019 - IPC C08J11/08 B29B17/02 C08F6/06 

FIELD: chemistry.

SUBSTANCE: present invention relates to a method of purifying a regenerated polyolefin homopolymer or copolymer, involving: a) obtaining a regenerated polyolefin homopolymer or copolymer, wherein said regenerated polyolefin homopolymer or copolymer is selected from a group consisting of polymers after household use, polymers after industrial use and combinations thereof; b) contacting the regenerated polyolefin homopolymer or copolymer at temperature of 80 to 220 °C and pressure of 1.03 MPa (150 pounds per square inch) to 103.42 MPa (15,000 psi) with a first liquid solvent with a standard boiling point of less than 70 °C to obtain an extracted regenerated polyolefin homopolymer or copolymer; c) dissolving the extracted regenerated polyolefin homopolymer or copolymer in a second liquid solvent with a standard boiling point of less than 70 °C at temperature from 90 to 220 °C and pressure of 2.41 MPa (350 pounds per square inch) to 137.90 MPa (20,000 pounds per square inch) to obtain a homopolymer or copolymer solution; d) separating the homopolymer or copolymer from said homopolymer or copolymer solution; wherein second liquid solvent has same chemical composition as first liquid solvent or other chemical composition, wherein said first and second liquid solvents are selected from a group consisting of aliphatic C₁-C₆ hydrocarbons and mixtures thereof.

EFFECT: technical result is a simpler and more cost-effective method of cleaning a regenerated polyolefin homopolymer in terms of the number of separate operations or a copolymer which results in obtaining a purified polymer product with improved colour characteristics, with low level of contaminants which is odourless, homogeneous and similar in properties to the initial polymer.

10 cl, 4 dwg, 1 tbl, 3 ex