Surface and structural modification of HCl-doped poly(MT-co-3-BA) copolymer and the feasibility study of humidity sensor

Abstract

ABSTRACT A new series of copolymers was synthesized through aqueous chemical oxidative polymerization, using m-toluidine and 3–3-bromoaniline as monomers. Various characterization techniques were employed to analyze the synthesized copolymer nanocomposite. The nanocomposite exhibited solubility in Dimethylformamide (DMF), Tetrahydrofuran (THF), Dimethyl sulfoxide (DMSO), and N-Methylpyrrolidone (NMP). The presence of π–π* and n–π* transitions, responsible for conjugation in the polymer backbone, was confirmed by absorption peaks observed at 357 and 602 nm. The FTIR spectra indicated the presence of benzenoid and quinoid rings, while the XRD pattern suggested an amorphous nature of the polymer. SEM imaging revealed agglomerated particles with smooth surfaces, along with one-dimensional fiber-like or tubular growth and a layered structure. The electroactive study of the composite confirmed its semiconducting nature, with a conductivity range of 6.46 × 10–3 to 2.40 × 10–5 S/cm. These findings suggest that the synthesized copolymer can serve as a promising material for the manufacturing of electric and electronic components in the sensor field.