Non-ionic recurring units may be formed from water-soluble monomers such as (alk)acrylamide, N-vinylpyridine, hydroxyalkyl(meth)acrylates, N-vinylpyrrolidone, etc., preferably (meth)acrylamide, or may be formed from hydrophobic monomers having low water solubility so long as the inclusion of the poorly water-soluble, e.g. hydrophobic, recurring units does not render the resulting polymer water-ins