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The oligomer of acrylic acid with a thiooctadecyl end-group was obtained by using octadecyl mercaptan as the chain-transfer agent. The resulting oligomer was characterized by 1H NMR and 13C NMR spectroscopy and critical micelle concentration was determined in aqueous solution. The order with respect to the initiator concentration was 0.5 and 1.6 with respect to the monomer concentration. The abnormal reaction order with respect to the monomer concentration was explained by participation in the chain propagation of unassociated and associated forms of acrylic acid, which were stabilized by formation of hydrogen bonds. The kinetic parameters of telomerization were determined. Telomerization with acrylic acid in the non-associated form had lower activation energy and lower pre-exponential factor than in the case of associated forms. The synthesis of the acrylic acid oligomer with a thiooctadecyl end-group having a low critical micelle concentration in water was carried out in one stage and corresponds to the concept of atom economy. [ABSTRACT FROM AUTHOR]

It was found that sulfanylethanoic and 3-sulfanylpropanoic acids are effective regulators of molecular weight with chain transfer constants of 0.441 and 0.317, respectively, and show an unexpected acceleration effect on the radical polymerization of N-vinyl-2-pyrrolidone, initiated by 2,2'-azobisisobutyronitrile. It was determined for the first time that the thiolate anions of mercapto acids form a high-temperature redox initiating system with 2,2'-azobisisobutyronitrile during the radical polymerization of N-vinyl-2-pyrrolidone in 1,4-dioxane. Considering the peculiarities of initiation, a kinetic model of the polymerization of N-vinyl-2-pyrrolidone is proposed, and it is shown that the theoretical orders of the reaction rate, with respect to the monomer, initiator, and chain transfer agent, are 1, 0.75, 0.25, and are close to their experimentally determined values. Carboxyl-containing techelics of N-vinyl-2-pyrrolidone were synthesized so that it can slow down the release of the anticancer drug, doxorubicin, from aqueous solutions, which can find its application in the pharmacological field. [ABSTRACT FROM AUTHOR]

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−1. 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. [ABSTRACT FROM AUTHOR]

• An equation is derived for estimating M ¯ n at polymerization of aniline derivatives. • M ¯ n increases proportionally to monomer conversion during oxidative polymerization. • The temperature dependence of M ¯ n was obtained for aniline polymerization. • M ¯ n increases proportionally to the ratio aromatic amine/oxidizing agent. • The effect of the oxidizing agent on M ¯ n in aniline polymerization is predicted. A theoretical approach has been proposed for the establishment of quantitative relationship between the number-average molecular weight of products of the oxidative polymerization of aromatic amines and both reagent concentrations and temperature. The derived equation to estimate the number-average degree of polymerization was evaluated using the corresponding experimental data reported in the literature. It was demonstrated that the developed theory can adequately describe an increase in the molecular weight of aromatic amine polymers upon an increasing monomer conversion and decreasing temperature and oxidizer/monomer molar ratio. Proposed assumptions about the mechanism of chain growth in the oxidative polymerization of aromatic amines reflect the key features of influence of the ratio of reactants and acidity of the medium, as well as the structure of oxidizing agent on the number-average degree of polymerization of the resulting polymers. Predictions about the influence of various factors on the molecular weight of products of the oxidative polymerization of aromatic amines have been made. [ABSTRACT FROM AUTHOR]