We have developed methodology to synthesise aqueous soluble polymers such as poly(acrylic acid) in flow, enabling access to a variety of molecular weights [L. Brocken, P. D. Price, J. Whittaker and I. R. Baxendale, React. Chem. Eng., 2017, in press]. However, full conversion was hard to achieve without increasing the dispersity and therefore purification was necessary. In this work we demonstrate that flow polymerisation can be directly coupled with purification to furnish a purified polymer sample in under one hour.