n this report, novel series of unsaturated polyesters Vad and VIad containing indazole moiety were successfully prepared via interfacial polycondensation technique of indazole derivatives III and IV with different aromatic and aliphatic acid chlorides; isophthaloyl, terephthaloyl, adipoyl, and sebacoyl chlorides. The prepared polyesters were categorized by elemental analyses, IR, ¹H NMR, Mass spectra, GPC, Thermogravimetric (TGA), X-ray analyses (XRD), and therefore the morphology was examined by scanning microscopy (SEM). They showed high thermal stability and different morphology structure. The corrosion protection performance of prepared polyesters Vad and VIad on X65steel in molar oil of vitriol was assessed using potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), and SEM. Electrochemical tests (EIS and PDP) displayed polymers could efficiently impede the …