METHOD OF DEGASSING AROMATIC POLYMER WITH ALKYLENE GROUP Russian patent published in 2012 - IPC C08F6/00 C08F6/10 C08F6/28 

FIELD: chemistry.

SUBSTANCE: method of degassing an aromatic polymer with an alkylene group is described, in which: a) a product aromatic polymer with an alkylene group in form of a mass of molten polymer is provided, also containing an aromatic monomer with an alkylene group, b) the mass of molten polymer is fed to a first degassing step to obtain a first gaseous stream containing an aromatic monomer with an alkylene group and oligomers, and a second stream containing the remaining part of the mass of molten polymer, c) water is added to the second stream as a washing substance to obtain a third stream containing the remaining part of the mass of molten polymer and water, d) the third stream is fed to a second degassing step to obtain a fourth gaseous stream containing water, an aromatic monomer with an alkylene group and oligomers, and a fifth stream containing a degassed mass of molten polymer, e) the fourth gaseous stream is fed to a separation step to obtain a sixth stream containing water and an aromatic monomer with an alkylene group, and a seventh stream containing oligomers, f) the sixth stream is fed to the separation step to separate an eighth stream containing water and a reduced amount of aromatic monomer with an alkylene group from a ninth stream containing the remaining part of the aromatic monomer with an alkylene group, g) the eighth stream is fed for azeotropic stripping in a stripping column in vacuum conditions using water vapour to obtain an overhead product stream containing water vapour and the main part of the aromatic monomer with an alkylene group which, together with the sixth stream, is fed to the separation step (f), and a bottom product stream containing water and a reduced amount of the aromatic monomer with an alkylene group, at least part of which is returned to step (c) as the washing substance.

EFFECT: reduced amount of water for recycling, reduced consumption of feed water used as the washing substance.

7 cl, 1 dwg, 1 ex