Размер и форма частиц полипиррола в водных растворах поли-( N-винилпирролидона)

Based on the IR spectroscopy data and on the analysis of rheological characteristics of polypyrrole aqueous suspension stabilized with poly-(N-vinylpyrrolidone) we conjecture that a physical lattice composed with poly-(N-vinylpyrrolidone) is formed, where the lattice points are the polypyrrole chain aggregates interlaced with poly-(N-vinylpyrrolidone) chains. It was shown that there is a hydrogen bond between the constitutional repeating units of poly-(N-vinylpyrrolidone) and polypyrrole. It was determined that the size of the particles of the disperse phase decreases with the increase of poly-(N-vinylpyrrolidone) molecular weight. It was also determined that the size of particles increases with the increase of the mass fraction of polypyrrole aqueous suspension. It was shown that the disperse phase particles are rod-like, and the increase of molecular weight of poly-(N-vinylpyrrolidone) in an aqueous solution results in additional lengthwise stretching of particles. It was also shown that the viscosity of the stabilized poly-(N-vinylpyrrolidone) aqueous suspension follows the Einstein law.На основании данных ИК-спектроскопии и анализа реологических характеристик водной суспензии полипиррола, стабилизированной поли-( N -винилпирролидоном), выдвинуто предположение об образовании физической сетки, формируемой цепями поли-( N -винилпирролидона), узлами которой являются агрегаты цепей полипиррола, переплетенные с цепями поли-( N -винилпирролидона). Установлено уменьшение размера частиц дисперсной фазы при увеличении молекулярной массы поли-( N -винилпирролидона)

КИНЕТИКА И МЕХАНИЗМ ОКИСЛИТЕЛЬНОЙ ПОЛИМЕРИЗАЦИИ 2-МЕТИЛАНИЛИНА

The kinetics of oxidative polymerization of 2-methylaniline in hydrochloric acid aqueous solution in the presence of ammonium peroxydisulfate as the oxidant was studied. The presence of autocatalysis was demonstrated, and the reaction mechanism was suggested. On the basis of the mechanism a kinetic model of oxidative polymerization of 2-methylaniline was built. The model is in satisfactory agreement with the experimental results.И сследована кинетика окислительной полимеризации 2-метиланилина в солянокислом водном растворе в присутствии пероксидисульфата аммония в качестве окислителя. Показано наличие автокатализа, предложен механизм реакции. На основании механизма построена кинетическая модель окислительной полимеризации 2-метиланилина, находящаяся в удовлетворительном соот-ветствии с результатами эксперимента

Кинетика и механизм окисления 2,4,6-триметиланилина

The kinetics of oxidation of 2,4,6-trimethylaniline hydrochloride with ammonia peroxydisulfate in an aqueous solution was studied by the potentiometric method. It was shown that the reaction proceeds as the second order process. The rate constants of one-electron transfer from 2,4,6-trimethylaniline molecule to peroxydisulfate ion were determined and are 1.46, 2.3, and 3.17 l/(mol.sec) at 30, 35 and 40° С , respectively. The activation energy of one-electron transfer from 2,4,6-trimethylaniline molecule to peroxydisulfate ion is 61 kJ/mol, the entropy of activation is –63 J/(mol К ), and the enthalpy of activation is 58.5kJ/mol. It was determined that 2,4,6-trimethylaniline is not prone to oxidative polymerization. This indicates that cation-radicals of aromatic amines which act as active centers of aniline oxidative polymerization are formed. The fact that there is no autoacceleration during oxidation of 2,4,6-trimethylaniline hydrochloride indicates that the oxidative polymerization of aniline is an autocatalytical process.Потенциометрическим методом исследована кинетика окисления 2,4,6-триметиланилина под действием пероксидисульфата аммония в водном растворе. Показано, что скорость реакции подчиняется уравнению второго порядка. Определены константы скорости и энергия активации окисления 2,4,6-триметиланилина, а также предложен механизм реакции