POLYMER BULLETIN, cilt.83, sa.7, 2026 (SCI-Expanded, Scopus)
In this study, the Schiff base 3-((2-phenylhydrazono)methyl)benzene-1,2-diol (3-PHMB) was synthesized through a condensation reaction between 2,3-dihydroxybenzaldehyde (2,3-DHBA) and phenylhydrazine (PH). The obtained Schiff base was subsequently subjected to oxidative polymerization in a 10% KOH (w/v) aqueous medium using hydrogen peroxide (35% H2O2), sodium hypochlorite (6-14% NaOCl), and oxygen (O-2) as oxidants, yielding the oligomers o-(3-PHMB)-P, o-(3-PHMB)-H, and o-(3-PHMB)-O. The structural, morphological, thermal, optical, and electrochemical characteristics of the synthesized compounds were comprehensively investigated using FT-IR, NMR, SEM, TG-DTA, UV-Vis, CV, and GPC techniques. UV-Vis and CV analyses revealed that the optical band gaps (E-g) were 2.33 eV for 3-PHMB, 2.06 eV for o-(3-PHMB)-P, 2.16 eV for o-(3-PHMB)-H, and 2.02 eV for o-(3-PHMB)-O, while the electrochemical band gaps (E-g ') were calculated as 2.03 eV, 1.65 eV, 1.63 eV, and 1.50 eV, respectively. Thermal analysis showed that the char yields at 1000 degrees C were 41.43% for o-(3-PHMB)-P, 38.72% for o-(3-PHMB)-H, and 44.35% for o-(3-PHMB)-O. Dielectric measurements indicated that o-(3-PHMB)-O exhibited higher polarization capacity and energy storage ability compared to the other oligomers. Moreover, the electrical conductivity values increased steadily with frequency; at 100 kHz, the conductivity was recorded as 1.74 & times; 10(-)(5) S cm(-)& sup1; for o-(3-PHMB)-O and 1.64 & times; 10(-)(5) S cm(-)& sup1; for o-(3-PHMB)-P. These findings demonstrate that the synthesized Schiff base oligomers are promising candidates for dielectric and optoelectronic applications due to their high thermal stability, controlled molecular weight distribution, and semiconducting properties.