Synthesis And Properties Of Polyesters Containing1,3,4-oxadiazole

In this paper,two kinds of compounds,2,6-bis-(2-methyl acetatesulfide-1,3,4-oxadiazole)-pyridine (4a) and1,3-bis-(2-methyl acetatesulfide-1,3,4-oxadiazole)-benzene (4b), are synthesized by esterifation, alkylation, cyclization,substitution with2,6-pyridinedicarboxylic acid and1,3-benzenedi-carboxylic acid as rawmaterials. Six kinds of polyesters (P1~P6) containing1,3,4-oxadiazole are synthesized bytransesterification with two kinds of monomers and triethylene glycol,tetraethyleneglycol,polyethylene glycol400as raw materials. The structure of the intermediates andpolyesters (P1~P6) are confirmed by IR, UV-vis,1H NMR,and MS. Polyesters (P1~P6) canbe dissolved in DMF, DMSO and NMP, the majority polyesters can be dissolved in DMAC,indicating that polyesters (P1~P6) show well solubility. Tested by GPC, polyesters’(P1~P6)Mnare5586~6681g/mol, Mwat the14021~18045g/mol, PDI in the2.44~2.87range. Testedby TG-DTA, Polyesters’(P1~P6)5%weight loss temperature at the272.9~288.3℃, themaximum weight loss temperature at the622.0~653.5℃, char yield in the19~30%,indicating that polyesters (P1~P6) show considerable thermal stability. Tested by fluorescencespectroscopy monomers (4a,4b) and polyesters’(P1~P6) fluorescent performance, the studyshows that the monomers (4a,4b) and polyesters (P1~P6) fluorescent maximum emissionpeaks at354~365nm wavelength range, monomers (4a,4b) and polyesters (P1~P6) both emitviolet fluorescence. The fluorescence quantum yield (φ) of monomers (4a,4b) and polyesters(P1~P6) are in the range of0.12~0.32. Polyesters (P1~P6) containing1,3,4-oxadiazole showwell solubility, considerable thermal stability and fluorescent properties, which can be in thefield of optical functional polymer materials.