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Synthesis and characterization of the nano-structured poly (1-amino-2-hydroxy-4-sulfonic acid)
Last modified: 2015-10-12
Abstract
In recent years, the synthesis of polymers containing functional groups has attracted the attention of many researchers due to their interesting optical, electronic and thermal characteristics. Among them, bi-functional or tri-functional polyarenes are widely used as composite materials with high stability, photoresist or fire resistant materials. In addition, the existence of functional groups in the polymer structure allows preparing new materials. These polymers have also a potential for analytical and environmental applications. In this study, the chemical oxidative polymerization of, 1-amino-2-hydroxy- naphthalene-4-sulfonic acid was performed by NaOCl (oxidant) in aqueous alkaline medium. The structure of the resulting polymer was characterized by FT-IR technique. Further characterization was performed using TG-DTA analysis. The solid state degradation kinetics of the obtained polymer was analyzed by using TG-DTG and DTA data from ambient temperature to 1000 0C in nitrogen atmosphere under isothermal conditions. TGA-DTG curves showed that the thermal decomposition occurred in two stages. They are attributed to the dehydration and thermal decomposition stage of polymer. Six kinetic methods based on single heating rates were used to investigate the thermal decomposition behavior of this polymer. The values of activation energy E, frequency factor A, reaction order n, entropy change ΔH≠, enthalpy change ΔS≠ and Gibbs free energy ΔG≠, related to the thermal decomposition were calculated by means of Coats-Redfern (CR), Horowitz-Metzger (HM), MacCallum-Tanner (MC), van Krevelen (vK), Madhusudanan-Krishnan-Ninan (MKN) and Wanjun-Yuwen-Hen-Cunxin (WHYC) methods. The activation energy values obtained by all the methods were in good agreement with each other.
Keywords
activation energy; 1-amino-2-hydroxy-naphthalene-4-sulfonic acid; thermal decomposition
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