Synthesis and characterization of novel organosoluble polyesters based on a DIOL with azaquinoxaline ring

Abstract

A series of new polyesters were synthesized by polycondensation of aliphatic and aromatic dicarboxylic dichlorides with a novel quinoxaline diol, 2,3-bis (4-hydroxy phenyl)-5-azaquinoxaline (DIOL). The DIOL was synthesized by reacting 4,4 0 -dihydroxy benzil with 2, 3-diaminopyridine (yield: 85%), and characterized by FTIR and 1 H-NMR spectra. All polyesters showed good solubility in most aprotic polar solvents such as NMP (Nmethylpyrrolidone), DMF (dimethylformamide), DMSO (dimethylsulfoxide), DMAc (dimethylacetamide), HMPA (hexamethylenephosphoramide), and Py (pyridine). The inherent viscosity of polyesters was obtained in the range of 1.1-1.22 dL/mg. The glass transition temperatures of the polyesters were in the range of 200-280 C, as determined by DSC. The initial decomposition temperatures of the polyesters were above 300 C and the char yield at 750 C ranged from 30 to 60% under nitrogen atmosphere.

Synthesis and characterization of new soluble polyamides from Acenaphtohydrazinomercaptotriazole diamine

“…DSC studies of some polyamides [11,12] were reported in literature. We successfully prepared aromatic polyamides [13] , polyimides [14] , polyesters, polyquinoxalines, from a number of new functional monomers [15] . Thermally stable polymers have received extensive interest due to the increasing demands for high temperature polymers as replacements for ceramics and metals in the automotive, aerospace, and microelectronics industries.…”