Aromatic polyesters from naturally occurring monosaccharides:: Poly(ethylene terephthalate) and poly(ethylene isophthalate) analogs derived from D-mannitol and galactitol

The synthesis and characterization of a new series of aromatic polyesters based on D-mannitol and galactitol are described. These polyesters were obtained by polycondensation reaction of the terephthaloyl chloride or isophthaloyl chloride and 2,3,4,5-tetra-O-methyl-D-mannitol or 2,3,4,5-tetra-O-methyl-galactitol in o-dichlorobenzene. All the new polyesters were characterized by elemental analyses, GPC, IR, and NMR. They were soluble in chloroform, but insoluble in water and other polar oxygenated solvents. They showed a notable hygroscopicity, lower for those containing isophthalic units. DSC and X-ray diffraction studies showed that D-mannitol-based polyesters were stiffer and less crystalline than those derived from galactitol, which presented a noticeably lower thermal stability. (c) 2005 Wiley Periodicals, Inc.