Fuente: WIPO "milk" Polymers of 1,2:3,4-diketals of galactose esterified in the 6-position with an a ,b -olefinically unsaturated mono- or di-carboxylic acid are prepared by polymerizing the corresponding monomeric ester (see Division C2) in the presence of a free radical catalyst. The ketal residues may then be removed from the polymer by controlled hydrolysis, e.g. in the presence of an aqueous organic acid such as formic acid. The galactose diketal may be esterified with, for example, acrylic, methacrylic, ethacrylic, a -chloroacrylic or a -cyanoacrylic acid, or maleic, fumaric or itaconic acid or their half-esters. The ketal groups may be derived from acetone, methyl ethyl ketone, methyl propyl ketone, monochloroacetone or cyclohexanone. Polymerization can be effected in bulk or in benzene using azobisisobutyronitrile as catalyst. The galactose diketal acrylates or methacrylates may be copolymerized with monomers such as methyl acrylate, methyl methacrylate or acrylonitrile. The polymers after removal of the ketal groups can be converted to acetate, benzoate, phenyl carbamate, phenylhydrazone and phenylosazone derivatives; they may also be nitrated with nitrogen pentoxide, reduced with sodium borohydride to the corresponding polygalactitol-6-ester, and oxidized with chlorous acid to the corresponding galactonic acid polymer (or 1,4-lactone thereof) which can then be neutralized to the salt form, e.g. sodium or calcium salt.ALSO:Esters of an a ,b olefinically unsaturated polymerizable mono- or di-carboxylic acid and the hydroxyl group in the six position of galactose, specifically diisopropylidene galactose 6-methacrylate and acrylate are novel compounds and are prepared by reacting a ketone with galactose to form a 1,2:3,4-diketal and then reacting with the unsaturated acid. Acids specified are acrylic, methacrylic, a -chloroacrylic, a -cyanoacrylic, maleic, half esters of maleic or fumaric, a -ethacrylic, itaconic and half esters thereof, and the ketones may be acetone, methyl ethyl ketone, methyl propyl ketone, mono-chloracetone, and cyclohexanone, and a polymerization inhibitor may be present.