Step-Growth Polymerization of 5-(3-Acetoxynaphthoylamino)isophthalic acid with Different Aromatic Diols

Soluble and photoactive novel aromatic polyesters containing acetoxynaphthalamide unit in the side chain have been synthesized with moderate molecular weights by direct polycondensation of 5-(3-acetoxynaphthoylamino)isophthalic acid with different aromatic diols using tosyl chloride (TsCl), pyridine (Py) and N,Ndimethylformamide (DMF) system as a condensing agent. The reaction was successfully applied to the preparation of thermally stable polyesters with good yields and inherent viscosities in the range of 0.28-0.62 dL/g. The resulted polymers are readily soluble in aprotic polar solvents such as N-methyl-2-pyrrolidone, N,N dimethylacetamide, DMF, Py and dimethyl sulphoxide. Thermogravimetric analysis data showed that these polyesters are thermally stable, with 10% weight loss being recorded above 360ºC. These macromolecules exhibited maximum UV-vis absorption at 269 and 320 nm in DMF solution. Their photoluminescence in DMF solution demonstrated fluorescence emission maxima around 360 and 428 nm for all polyesters obtained.