The present invention relates to a polymer comprising: (a) from 9.49 mol-% to 98 mol-% repeating units according to Formula (1) wherein at least 10 wt.-% of the repeating units according to Formula (1) comprise from 28 wt.-% to 100 wt.-% bio-based carbon content, relative to the total mass of carbon in the repeating unit according to Formula (1), measured according to standard ASTM D6866-12, Method B；(b) from 0.01 mol-% to 5 mol-% crosslinking or branching units； (c) from 0.01 mol-% to 88.52 mol-% of repeating neutral structural units； (d) from 1.98 mol-% to 20 mol-% of repeating anionic structural units, wherein the repeating anionic structural units result from the incorporation of a monomer comprising at least one carboxylate anion, and wherein the repeating anionic structural units are different from units (a).
