Disclosed are unsaturated polyester resins comprising residues of 1,2-propanediol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, an aliphatic, cycloaliphatic, or aromatic diacid, and 2-butenedioic acid. Also disclosed are curable compositions containing admixtures of the unsaturated polyesters and aromatic vinyl compounds copolymerizable with the unsaturated polyesters, and coatings and casted and molded articles obtained from the curable compositions. The curable compositions are useful for coatings and casted and molded articles that have at least one surface that is persistently exposed to organic or aqueous liquids.