Synthesis and properties of poly(D-mannaramide)s and poly(galactaramide)s

We describe a series of new aregic polyamides of the AABB-type by polycondensation reaction of pentachlorophenyl 2,3,4,5-tetra-O-methyl-D-mannarate or pentachlorophenyl 2,3,4,5-tetra-O-methyl-galactarate with different diamines. Fully sugar-based polyamides have been prepared from the aldaric esters and the dihydrochlorides of 1,5-diamino-1,5-dideoxy-2,3,4-tri-O-methyl-L-arabinitol or 1,5-diamino-1,5-dideoxy-2,3,4-tri-O-methylxylitol. Polyamides derived from the aldaric esters and non-carbohydrate alkylenediamines are also investigated. All the polyamides were soluble in the usual organic solvents, and slightly soluble in water. All of them were very hygroscopic, especially those that were fully sugar-based. DSC and X-ray powder diffraction studies showed that most of them are crystalline and that the thermal properties and crystal structure of these carbohydrate-based polyamides depend on their constitution and on the configuration of the carbohydrate-based moiety.