V. A. Kraikin

Radical polymerization of methyl methacrylate and styrene in the presence of ferrocene

Abstract The influence of ferrocene on the kinetic parameters of methyl methacrylate (MMA) or styrene polymerization is investigated. It is shown, that in the presence of ferrocene the growth of the initial rate of polymerization is accompanied with significant decrease of the polymerization degree of polymer obtained when peroxides are used as the polymerization initiators. The polymerization kinetics parameters are evaluated. Its demonstrated that the process of polymerization in the presence of a ferrocene has a low activation energy, that allows to carry out the polymerization at lower room temperatures. The influence of the ferrocene on the molecular-mass characteristics of poly(methyl methacrylate) (PMMA) was studied and it was found that the influence of ferrocene on PMMA molecular mass is determined by the nature of the initiator used. The decomposition temperature of PMMA increases with the increase of ferrocene concentration. Monte-Carlo technique was used for numerical simulation of MMA radical polymerization kinetics in the presence and in the absence of ferrocene and to follow the change of molecular-weight distribution during the polymerization. The peculiarities of polymer radical concentration changes at the initial stage of polymerization are shown. Satisfactory correspondence between calculated and experimental data was obtained.

Synthesis of polyarylenephthalides prospective as smart polymers

The data on the synthesis of polyarylenephthalides, their analogs, and derivatives are surveyed. The main attention is given to the synthesis of polyarylenes through the polycondensation of pseudoacid chlorides according to several variants, predominantly via the self-condensation of pseudoacid chlorides, which may be depicted by the general scheme Open image in new window (−RH is the radical of aromatic or heterocyclic polynuclear hydrocarbon.). The reaction affords polyarylenephthalides (I) (X = CO, Y = O), polyarylenephthalimidines (II) (X = CO, Y = NR1, where R1 is an aromatic hydrocarbon), and polyarylenesulfophthalides (III) (X = SO2, Y = O). Polymers I and II hold promise for designing thermostable, heat-(T g ≥ 420–470°C) and chemoresistant, and functional materials. One should distinguish the valuable functional properties of polymers I and III that make them prospective as smart polymers, namely, the switching effect induced by temperature, pressure, and electric and magnetic fields along with changes in color, electro-and photoluminescence. Owing to the presence of sulfophthalide groups, polymers III are candidates for use as latent polyelectrolytes. With consideration for the foregoing reasoning, phthalide-containing polyarylenes of several other classes, namely, polyaryleneketones, poly(arylene ether ketones), polyarylates, oligomer resols, and crosslinked systems on their basis, which are prospective as smart polymers, have been synthesized.

Hydrochlorinated Derivatives of Syndiotactic 1,2-Polybutadiene

Chlorine-containing polymeric products with a degree of functionalization of up to 70% are synthesized through the hydrochlorination of syndiotactic 1,2-polybutadiene via carbon-carbon double bonds. The introduction of chlorine atoms into polydiene units causes substantial changes in the viscosity of polymer solutions, the flowability of the polymer melt, the glass-transition and flow temperatures, and the thermal stability of polymers. The hydrochlorinated derivatives of syndiotactic 1,2-polybutadiene demonstrate good adhesion with respect to steel and can be used in adhesive compositions.

Voltammetric identification of antiarrhythmic medicines using principal component analysis

Possibilities of voltammetry are considered as applied to problems of the identification of antiarrhythmic medicines from various producers using an electronic tongue based on glassy carbon electrodes modified by polyarylene phthalides. The electrochemical behavior of electroactive compounds in the composition of antiarrhythmic medicines was studied; the optimum conditions of recording voltammograms are found; and a method of the voltammetric identification of atenolol and propranolol using principal component analysis is proposed.

Controlling the polymerization of methyl methacrylate with ternary initiating systems

The effect of ternary initiating systems benzoyl peroxide-ferrocene-3,6-bis(o-carboxybenzoyl)-N-isopropylcarbazole and benzoyl peroxide-di-η5-indenylzirconium dichloride-3,6-bis(o-carboxybenzoyl)-N-isopropylcarbazole on the radical polymerization of methyl methacrylate and on the heat resistance and microstructure of the resulting polymers was examined.

Effect of a three-component initiation system ferrocene-zirconocene dichloride-benzoyl peroxide on the free-radical polymerization of methyl methacrylate

The free-radical polymerization of methyl methacrylate initiated by the three-component system ferrocene-zirconocene dichloride-benzoyl peroxide has been studied. The kinetic features of the process, the interaction between components of the initiation system, and the molecular characteristics of the polymers have been investigated. In the case of the three-component initiation system, the content of syndiotactic fragments grows and the thermal stability of the polymers is improved compared to the products of polymerization carried out in the presence of solely a peroxide initiator.

Voltammetric determination of bisoprolol on a glassy carbon electrode modified by poly(arylene phthalide)

New voltammetric sensors based on glassy carbon electrodes (GCEs) modified by poly(arylene phthalide) are studied. The electrochemical behavior of bisoprolol on GCEs modified by poly(arylene phthalide) is investigated. The effects of potential scan rate, time of accumulation on the electrode, pH of supporting electrolyte, and concentration on the current of bisoprolol electrooxidation are estimated. A procedure is developed for the voltammetric determination of bisoprolol on glassy carbon electrodes modified by poly(arylene phthalide). The dependence of the analytical signal on the concentration of bisoprolol is linear in the range 10–6–10–5 M with the limit of detection (3.4–9.8) × 10–8 M.

Radical copolymerization of N,N-Diallyl-N,N-dimethylammonium chloride and fumaric acid

The copolymerization of N,N-diallyl-N,N-dimethylammonium chloride and fumaric acid under conditions of radical initiation is studied. The reaction yields copolymers that exhibit a random distribution of comonomer units in the macrochain. Fumaric acid is highly active in the copolymerization of the above system. A significant effect on the relative activity of the comonomers is exerted by the type of solvent. The kinetics of the copolymerization is studied; the structuring of the copolymers is determined.

Research into methanofullerenes with various substitution degrees by UV spectroscopy

A qualitative and quantitative UV spectroscopic study of C60 fullerene and methanofullerene (1,2-dihydro-C60-fullerene) compounds differing in the degree of functionalization has been carried out. In solvents with different polarities, the molar absorptivity of C60 and the mono-substituted 1,2-dihydro-C60-fullerenes has been determined. It was found that the extinction coefficient of C60 at 330 nm does not depend on the solvent nature and amounts to ∼54 400 M−1 cm−1. The molar absorption coefficients of the mono-substituted 1,2-dihydro-C60-fullerenes are practically independent of the chemical structure and length of the substituent. As for the methanofullerene compounds with different degrees of functionalization, it is shown that as the number of substituents increases, a hypsochromic shift of the characteristic absorption bands and a decrease in the optical density of these substances in solution occur. An exponential dependence of molar absorption methanofullerene coefficients from the degree of fullerene compounds is revealed. A spectroscopic method for analyzing the methanofullerene compounds with different numbers of substituents has been developed. The good reproducibility and sensitivity of the methods suggested are demonstrated on model mixtures of fullerene derivatives. An analysis of the reaction mixture obtained by the interaction of fullerene and diallyl ether malonate is also given.

13C NMR spectroscopy of copoly(arylenephthalide) derivatives with diphenyloxide and terphenyl fragments in the main chain.

1H and 13С NMR spectral assignments have been provided for low‐molecular reference monomers, poly(diphenyleneoxidephthalide) and periodic copoly(arylenephthalide) derivatives such as AB, ABB, and ABBB (where A = terphenylenephthalide and B = diphenyleneoxidephthalide) using 1H‐1H COSY, 1H‐13C HSQC and HMBC NMR techniques. Distinctive 13C NMR chemical shifts of a main chain have been observed containing fragments of similar structures and lateral phthalate groups being part of various diads. Copyright