Mezhuev Yaroslav O, Vorobev Igor Y, Plyushchii Ivan V, Krivoborodov Efrem G, Artyukhov Alexander A, Motyakin Mikhail V, Luss Anna L, Ionova Irina S, Kovarskii Alexander L, Derevnin Igor A, Dyatlov Valerie A, Alekperov Ruslan A, Toropygin Ilya Y, Volkov Mikhail A, Shtilman Mikhail I, Korshak Yuri V
Department of Biomaterials, Mendeleev University of Chemical Technology of Russia, 125047 Moscow, Russia.
Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 119334 Moscow, Russia.
Polymers (Basel). 2021 Jun 30;13(13):2188. doi: 10.3390/polym13132188.
The kinetic regularities of the initial stage of chemical oxidative polymerization of methylene blue under the action of ammonium peroxodisulfate in an aqueous medium have been established by the method of potentiometry. It was shown that the methylene blue polymerization mechanism includes the stages of chain initiation and growth. It was found that the rate of the initial stage of the reaction obeys the kinetic equation of the first order with the activation energy 49 kJ × mol. Based on the proposed mechanism of oxidative polymerization of methylene blue and the data of MALDI, EPR, and IR spectroscopy methods, the structure of the polymethylene blue chain is proposed. It has been shown that polymethylene blue has a metallic luster, and its electrical conductivity is probably the result of conjugation over extended chain sections and the formation of charge transfer complexes. It was found that polymethylene blue is resistant to heating up to a temperature of 440 K and then enters into exothermic transformations without significant weight loss. When the temperature rises above 480 K, polymethylene blue is subject to endothermic degradation and retains 75% of its mass up to 1000 K.
通过电位滴定法确定了在过硫酸铵作用下，亚甲基蓝在水介质中化学氧化聚合初始阶段的动力学规律。结果表明，亚甲基蓝的聚合机理包括链引发和链增长阶段。发现反应初始阶段的速率服从一级动力学方程，活化能为49 kJ×mol。基于所提出的亚甲基蓝氧化聚合机理以及基质辅助激光解吸电离飞行时间质谱（MALDI）、电子顺磁共振（EPR）和红外光谱法的数据，提出了聚亚甲基蓝链的结构。结果表明，聚亚甲基蓝具有金属光泽，其导电性可能是由于长链段共轭以及电荷转移复合物形成的结果。发现聚亚甲基蓝在加热至440 K温度之前具有热稳定性，然后进入放热转变，且质量损失不显著。当温度升至480 K以上时，聚亚甲基蓝发生吸热降解，在1000 K时保留其75%的质量。
