US 12,486,619 B2
Membrane separation process for vinylamine-containing polymers
Cecil Coutinho, Wilmington, DE (US); Sachin Borkar, Wilmington, DE (US); and Shantanu Nikam, Wilmington, DE (US)
Assigned to SOLENIS TECHNOLOGIES, L.P., Wilmington, DE (US)
Filed by SOLENIS TECHNOLOGIES, L.P., Wilmington, DE (US)
Filed on Feb. 23, 2023, as Appl. No. 18/173,107.
Prior Publication US 2024/0287742 A1, Aug. 29, 2024
Int. Cl. D21H 17/07 (2006.01); B01D 61/02 (2006.01); B01D 61/14 (2006.01); B01D 61/58 (2006.01); B01D 69/02 (2006.01); C07C 209/86 (2006.01); C08F 26/02 (2006.01); D21H 21/10 (2006.01)
CPC D21H 17/07 (2013.01) [B01D 61/027 (2013.01); B01D 61/145 (2013.01); B01D 61/58 (2013.01); B01D 69/02 (2013.01); C07C 209/86 (2013.01); C08F 26/02 (2013.01); D21H 21/10 (2013.01); B01D 2311/08 (2013.01); B01D 2325/20 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A method of removing salts, by-products, and low molecular weight polymers from a solution of vinylamine-containing polymer comprising;
providing the solution of vinylamine-containing polymer, wherein the polymer comprises salts and by-products formed during vinylamine-containing polymer synthesis and/or modification of a vinylamine-containing polymer solution;
circulating the solution through a nanofiltration membrane and/or an ultrafiltration membrane having a molecular cutoff of from about 500 Dalton to 1,000 Dalton, thereby separating a low molecular weight from a high molecular weight retentate of the vinylamine-containing polymer and at least a portion of the salts and by-products; and
collecting a vinylamine-containing polymer retentate having a weight average molecular weight of from about 10,000 to about 1,000,000 Da. and a reduced amount of salts and by-products as compared to the solution prior to circulating through the nanofiltration membrane and/or an ultrafiltration membrane.