Process for removing residual monomers and oligemers from amine-containing polymers
AssigneeRohm and Haas Company
InventorsRobert L. Albright, Jon R. Fisher, Eric G. Isacoff, Eric C. Peters
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Abstract
Treatment of water-soluble, amine-containing polymers with strong acid, cation exchange resins from aromatic copolymer crosslinked with 2-25% polyvinyl crosslinker, followed by ultrafiltration with a membrane filter having a molecular-weight cutoff, measured against the polymers to be treated, of about 10,000 to about 15,000, results in a highly effective removal of residual monomers and oligomers of less than 500 molecular weight.
Claims11
A process for removing residual monomers and oligomers with molecular weights smaller than about 500 daltons from a polymer composition, which process comprises the sequential steps of first treating the composition with a strong-acid, aromatic cation exchange resin with a crosslinker level from about 2% to about 25%, and subsequently subjecting the composition to ultrafiltration with an ultrafiltration membrane to remove the remaining monomers and oligomers from the ultrafiltration retentate, wherein the polymer composition comprises linear, amine-containing polymers having a molecular weight within the range of from about 2000 to about 10 million daltons, or solutions thereof in water or a lower alcohol, and wherein the membrane has a molecular weight cutoff, measured against the polymers from which the monomers and oligomers are to be removed, of from about 10,000 to about 15,000 daltons.
Dependencies are inferred from the claim text.