FURAN DICARBOXYLATE COPOLYESTERS

Disclosed are copolyesters based on a furan dicarboxylic component (in the form of a carboxylic acid or an ester forming derivative thereof) and a lower alkyl diol component. The furan dicarboxylic component is a mixture of a 2,5-furan dicarboxylic component and a 2,4-furan dicarboxylic component. The mixture is such as to have a molar ratio of the 2,5-furan dicarboxylic residue to the 2,4-furan dicarboxylic residue in a range of from 95:5 to 65:35, preferably from, 90:10 to 80:20. Interestingly, the copolyesters of the invention can also be prepared from a mixture of furan dicarboxylic components as obtained from subjecting furoic acid salts to a disproportionaton reaction. This is of advantage, since these furoic acid salts can be obtained from biomass comprising furfural compounds. The lower alkyl diol is selected from the group consisting of short-chain alkane diols, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, isosorbide, isomannide, isoidide, and mixtures thereof, wherein the short-chain alkane diols satisfy the formula: HO-CHR 1 -(CR 3 R 4 ) n -CHR 2 -OH (formula I), wherein n is 0, 1, or 2, and R 1 , R 2 , R 3 and R 4 each independently are H or CH 3 . Copolyesters of the invention have suitable properties as substitutes for PET.