Sulfonated substantially random interpolymers made from monomer components comprise from 1 to 65 mole percent of (a) at least one vinyl or vinylidene aromatic monomer, or (b) at least one hindered aliphatic or cycloaliphatic vinylidene monomer, or (c) a combination of at least one vinyl or vinylidene aromatic monomer and at lest one hindered aliphatic or cycloaliphatic vinylidene monomer, and from 35 to 99 mole percent of at least one aliphatic α-olefin having from 2 to 20 carbon atoms; and optionally, from 0 to 20 mole percent of a diene containing from 4 to 20 carbon atoms; wherein the sulfonated interpolymer contains at least one mer (or moiety) of a group represented by the formula —SO3−M where M is hydrogen or a group 1, 7 or 12 metal in ionic form or combination thereof. Blends of these polymers with polyamides and polyolefins are made.