The oxidative polycondensation reaction conditions of 4-[(2-mercaptophenyl) imino methyl] phenol (2-MPIMP) were studied in an aqueous acidic medium between 40 and 90 C by using oxidants such as air, H 2 O 2 , and NaOCl. The structures of the synthesized monomer and polymer were confirmed by FTIR, 1 H NMR, 13 C NMR, and elemental analysis. The characterization was made by TGA-DTA, size exclusion chromatography (SEC) and solubility tests. At the optimum reaction conditions, the yield of poly-4-[(2-mercaptophenyl) imino methyl]phenol (P-2-MPIMP) was found to be 92% for NaOCl oxidant, 84% for H 2 O 2 oxidant 54% for air oxidant. According to the SEC analysis, the number-average molecular weight (M n ), weight-average molecular weight (M w ), and polydispersity index values of P-2-MPIMP were found to be 1700 g mol À1 , 1900 g mol
À1, and 1.118, using H 2 O 2 ; 3100 g mol À1 , 3400 g mol
À1, and 1.097, using air; and 6750 g mol
À1, 6900 g mol À1 , and 1.022, using NaOCl, respectively. According to TG analysis, the weight losses of 2-MPIMP and P-2-MPIMP were found to be 95.93% and 76.41% at 1000 C, respectively. P-2-MPIMP showed higher stability against thermal decomposition. Also, electrical conductivity of the P-2-MPIMP was measured, showing that the polymer is a typical semiconductor. The highest occupied molecular orbital, the lowest unoccupied molecular orbital, and the electrochemical energy gaps (E 0 g ) of 2-MPIMP and P-2-MPIMP were found to be À6. 13, À6.09; À2.65, À2.67; and 3.48, 3.42 eV, respectively. Kinetic and thermodynamic parameters of these compounds investigated by MacCallum-Tanner and van Krevelen methods. The values of the apparent activation energies of thermal decomposition (E a ), the reaction order (n), pre-exponential factor (A), the entropy change (DS*), enthalpy change (DH*), and free energy change (DG*) were calculated from the TGA curves of compounds.