Synthesis and physicochemical properties of poly[2-(cyclohex-2-en-1-yl)aniline] as a new polyaniline derivative

Abstract

In this study, a new polyaniline (PANI) derivative, poly[2-(cyclohex-2-en-1-yl)aniline], was synthesized for the first time. It was shown by varying the synthetic parameters that the highest polymer yield was obtained if HNO₃ and (NH₄)₂S₂O₈ were used. It was found that variation in the conditions for synthesizing poly[2-(cyclohex-2-en-1-yl)aniline] resulted in changes in the optical properties, for example, the PANI derivative obtained in HClO₄ medium and in the presence of (NH₄)₂S₂O₈ demonstrated the highest luminescence quantum yield (0.05). Using thermogravimetric analysis of poly[2-(cyclohex-2-en-1-yl)aniline], the main three stages of the polymer thermal degradation were identified. Processing of thermogravimetric curves allowed us to calculate the kinetic and thermodynamic parameters of the thermal degradation of the polymer at various heating rates. The use of poly[2-(cyclohex-2-en-1-yl)aniline] as a sensitive material in resistive sensors showed a high response of electrical conductivity to the changes in humidity (% RH) and ammonia concentration in the environment. The presented results demonstrate an efficient method for PANI modification that favors an improvement in solubility, appearance of photoluminescent properties, and broadening the practical application.