Journal of the American Chemical Society, Vol.116, No.2, 571-578, 1994
Hydroxylated Nylons Based on Unprotected Esterified D-Glucaric Acid by Simple Condensation-Reactions
Convenient procedures are described for the preparation of hydroxylated nylons (polyhydroxypolyamides) from D-glucaric acid. The procedures, which do not require protection/deprotection of carbohydrate hydroxyl groups, can be used to make a variety of polymers with a range of properties from D-glucaric acid. Simple alcohol (e.g. methanol or ethanol) esterification mixtures of D-glucaric acid (from oxidation of D-glucose) were reacted with bis-primary diamines in a polar solvent, typically methanol, to produce the polyamides. D-Glucaric acid esterification mixtures contain varying amounts of dialkyl D-glucarate, alkyl D-glucarate 1,4-lactone, and alkyl D-glucarate 6,3-lactone. These ester forms of D-glucaric acid are also in equilibrium under the conditions of the polymerization. Diamines employed included linear alkylenediamines, a branched alkylenediamine, arylalkylenediamines, and diamines with oxygen or nitrogen atoms in the alkylene chain. Considerable differences in polymer physical properties were observed by changing the diamine monomer. Linear aliphatic and arylalkylenediamines gave crystalline solid polyamides with high melting points. The C2 and C4 diamine copolymers were water soluble, whereas the C6 and above were water insoluble. The branched diamine copolymer and those with oxygen or nitrogen in the diamine chain had lower melting points and higher alcohol solubility than the unbranched alkylenediamine copolymers.
Keywords:POLYAMIDES