Polymers made from cholic acid derivatives: Selected properties

Polymers of methacrylate and methacrylamide derivatives of cholic acid were prepared by free radical polymerization in solution. To verify the stereoisomeric effect of the monomeric units, certain properties of the resulting polymers were compared, including conversion rate, molecular weight, and glass transition temperature. The 3 beta-epimers of the methacrylates and methacrylamides are to polymerize more easily than the 3 alpha-epimers. Water absorption experiments showed that the methacrylamide polymers are more hydrophilic than the methacrylate polymers and that the polymers from the 3 beta-epimers have higher hydrophilicity than those made from the 3 alpha-epimers. The free acid forms of the polymers were also prepared by selective hydrolysis of the methyl eater group of the cholic acid moiety which resulted in improved hydrophilicity of the polymers.