Enhanced Thermal Stability and Tailored Morphology of Poly(Aniline‐Co‐Pyrrole)/Montmorillonite‐H ⁺ Nanocomposites via In Situ Oxidative Polymerization

This work reports on the synthesis and characterization of nanostructured composites based on proton‐exchanged montmorillonite (MMT‐H + ) and conducting polymers, namely, polyaniline (PANI), polypyrrole (PPy), and poly(aniline‐co‐pyrrole) (P(ANI‐co‐Py)), prepared via in situ oxidative polymerization using ammonium persulfate (APS) as the oxidant. Structural investigations by X‐ray diffraction (XRD), X‐ray fluorescence (XRF) spectrometry, Fourier‐transform infrared (FT‐IR) spectroscopy, and scanning electron microscopy (SEM) confirmed the successful intercalation of the polymers within the MMT‐H + interlayers. The copolymer P(ANI‐co‐Py) exhibited an intermediate basal spacing ( d (001) = 24.86 Å), larger than that of PANI (22.87 Å) and PPy (22.46 Å). SEM analysis revealed pronounced morphological differences: PANI generated porous and granular structures, PPy formed dense globular aggregates, whereas the copolymer displayed heterogeneous porosity, leading to increased surface area and enhanced interfacial interactions. Optoelectronic and electrochemical analyses (UV–Vis and cyclic voltammetry [CV]) highlighted clear synergistic effects in the P(ANI‐co‐Py)/MMT‐H + nanocomposite. The electrochemical tunability originates from the combined redox activity of aniline (ANI) and pyrrole (Py) units, resulting in merged and broadened redox responses intermediate between those of the corresponding homopolymers, while UV–Vis spectra exhibit broadened absorption bands indicative of extended conjugation. Thermal characterization using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) demonstrated superior thermal stability of the copolymer nanocomposite, marked by an extended degradation range (200–600°C), a 40% increase in residual mass at 800°C, and a delayed degradation onset compared to the homopolymer systems. These improvements were attributed to nanoconfinement and cross‐linking effects. These results identify P(ANI‐co‐Py)/MMT‐H + as a thermally stable and electrochemically tunable nanocomposite with optimized morphology, suitable for high‐temperature electronic applications and advanced functional coatings.