Thermodynamic, Kinetic, Conductivity, and Theoretical DFT Study of Poly (p-Toluidine) and Starch -Grafted Poly (p-toluidine) Copolymer
Poly (p-toluidine) (PPT) and starch-grafted poly (p-toluidine) copolymer (SGPPT) were synthesized via oxidative polymerization. PPT and SGPPT were prepared using toluidine monomer, starch, hydrochloric acid, ammonium persulfate, and sodium hydroxide. The structure was corroborated through a diverse range of characterization techniques, including field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD) analysis, which elucidated the crystalline transformation of (PPT) in association with starch-grafted copolymer. The vibrational modes were measured by Fourier-transform infrared spectroscopy (FTIR). UV–Vis Spectrophotometer revealed distinctive peaks indicative of polymer formation and the energy gap from 3.62 eV for un-grafted (PPT) to 2.37 eV for the SGPPT copolymer, as elucidated through the Tauc plot. Thermogravimetric analysis (TGA) was employed to determine thermodynamic and kinetic parameters, demonstrating the first-order reaction kinetics of both polymers. The conductivity of thin films of polymer and copolymer was measured, exhibiting ohmic behavior, with higher conductivity observed in the copolymer. Additionally, a theoretical study for the first time for this polymer and copolymer using density functional theory (DFT) calculations with the B3LYP/6-311++G(d,p) basis set, revealing a relationship between trimers of PPT and SGPPT and the energy gap. Overall, this study demonstrates the successful synthesis and characterization of poly (p-toluidine) and starch-grafted poly (p-toluidine) copolymer, highlighting their potential applications in various fields.