Chemical Polymerization Kinetics of Poly-O-Phenylenediamine and Characterization of the Obtained Polymer in Aqueous Hydrochloric Acid Solution Using K₂Cr₂O₇as Oxidizing Agent

Abstract

The oxidative chemical polymerization of o-phenylenediamine (OPDA) was studied in hydrochloric acid solution using potassium dichromate as oxidant at 5°C. The effects of potassium dichromate, hydrochloric acid, and monomer concentrations on the polymerization reaction were investigated. The order of reaction with respect to potassium dichromate, hydrochloric acid, and monomer concentration was found to be 1.011, 0.954, and 1.045, respectively. Also, the effect of temperature on the polymerization rate was studied and the apparent activation energy of the polymerization reaction was found to be 63.658 kJ/mol. The obtained polymer was characterized using XPS, IR, UV-visible, and elemental analysis. The surface morphology of the obtained polymers was characterized by X-ray diffraction and transmission electron microscopy (TEM). The TGA analysis was used to confirm the proposed structure and number of water molecules in each polymeric chain unit. The ac conductivity(σac)of (POPDA) was investigated as a function of frequency and temperature. The ac conductivity was interpreted as a power law of frequency. The frequency exponent (s) was found to be less than unity and decreased with the increase of temperature, which confirms that the correlated barrier hopping model was the dominant charge transport mechanism.

Graphene Aerogels for In Situ Synthesis of Conductive Poly(para-phenylenediamine) Polymers, and Their Sensor Application

“…The synthesis of conductive poly(p-phenylenediamine) (p(p-PDA)) was carried out in accordance with the literature [ 69 , 70 , 71 , 72 ]. In short, 25 mL 0.5 M p(p-PDA) solutions were prepared in DDW.…”

“…For in situ synthesis of conductive p(p-PDA) polymers within GA networks, the earlier reports on p(p-PDA) synthesis were followed with some modifications [ 69 , 70 , 71 , 72 ]. Accordingly, the GAs were placed into 0.5 M 50 mL aqueous solutions of p-PDA and stirred for 1 h at 100 rpm in dark for loading of p-PDA monomers into pores and pore walls of the GAs.…”

Synthesis and Characterization of Some New Monemer and Polymers Containing Hetero Cyclic Rings With Study of Their Physical Properties.

“…The FT-IR spectrum of compound [C 1 ] exhibited significant two bands in the region (3471 cm -1 ) [6] which attributed to the stretching vibration bands of NH 2 group beside this a band at about (1598 cm -1 ) due to streching vibration band of cyclic imine group C=N [7,8]. The FT-IR spectrum of compound [C 2 ] by disappearance of νNH 2 absorption band combined with appearing of νOH absorption band at (3470 cm -1 ) [6], also absorption band appeared at (1681 cm -1 ) [8] due to νC=N of schiff base. FT-IR spectra show a clear strong absorption band indicating ester formation at (1750-1765) cm -1 and (1180-1199) cm -1 for νC=O and C-O group respectively due to polyester [9].…”

Copolymerization of poly (o-phenylenediamine-co-o/p-toluidine) via the chemical oxidative technique: synthesis and characterization

“…[8][9] Polymerization of a conducting polymer may be performed with chemical 10 or electrochemical 11 methods. Different chemical oxidizing agents such as potassium dichromate, [12][13][14] potassium iodate, 15 hydrogen peroxide, 16 ferric chloride or ammonium persulphate 17 can be used. The application of polyaniline is limited because of its poor processability, 18 which is true for most conducting polymers.…”