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Simultaneous administration of a copolymer of N-vinylpyrrolidone and 2-methyl-5-vinylpyridine and cytostatic agents to mice with a variety of implanted tumors was found to increase treatment efficacy, promoting increases in survival time. This effect is of interest for further studies of the possible use of copolymer as an immunomodulator in chemotherapy.

Aseries of N-oxides of N-vinylpyrrolidone and 2-methyl-5-vinylpyridine copolymers with various degrees of oxidation were prepared via oxidation of the copolymers by peracetic acid. The N-oxidation kinetic rate constants were calculated using UV spectrophotometry. The temperature dependence of the limiting N-oxidation was determined. The molecular-weight characteristics of the N-oxidized copolymers were established using 13C NMR methods. An approach based on direct UV spectrophotometry was proposed for practical monitoring of the reaction completion (degree of conversion).

Aqueous solutions of three samples of N-vinylpyrrolidone and 2-methyl-5-vinylpyridine copolymers with different ratios of monomer units were studied by spectrophotometry. Concentration dependences of the solution optical density at 269 nm were obtained. Specific absorption coefficients of these solutions were calculated. Regions of pH and temperature with the most consistent determinations were found. The results could provide a basis for developing a quantitative determination method for N-vinylpyrrolidone and 2-methyl-5-vinylpyridine copolymers in aqueous solutions.

Techniques for quantitative determination of N-vinylpyrrolidone and 2-methyl-5-vinylpyridine copolymers in aqueous solutions were developed. The spectrophotometric technique allowed the copolymer concentration in dilute solutions (0.8 – 1.2 mg/mL) to be determined even in the presence of the interfering additive merthiolate. The refractometric technique was simpler and allowed the copolymer concentration in concentrated solutions (> 1 mass%) to be determined.

A process of the graft polymerisation of 2-methyl-5-vinylpyridine induced by plasma on the surface of poly(ethylene terephthalate) track membranes (PET TM) was investigated. The surface properties and hydrodynamic properties of the composite membranes produced in this case have been studied. It is shown that the water permeability of the obtained polymeric membranes can be controlled by changing the filtrate pH.

The water solubility of N-vinylpyrrolidone and 2-methyl-5-vinylpyridine copolymers with various monomer ratios was investigated. Aqueous solutions of the copolymers had low critical mixing temperatures. The water solubility of the copolymers decreased with increasing pH and concentration of 2-methyl-2-vinylpyridine monomers. Correlation dependences for predicting the concentration and pH range of the homogeneous solution at a given mixing temperature were determined. The results were useful for creating injection-ready drug forms based on N-vinylpyrrolidone and 2-methyl-5-vinylpyridine copolymers.

The relaxation properties of chemisorption fibers based on copolymers of acrylonitrile and 2-methyl-5-vinylpyridine synthesized in aqueous medium and in dimethyl sulfoxide were investigated. It was shown that the conditions of synthesis of the copolymers affect the relaxation properties of the fibers. It was hypothesized that the change in the relaxation properties is due to the composite composition of the copolymers, which is determined by the copolymerization constants.

A copolymer of N-vinylpyrrolidone and 2-methyl-5-vinylpyridine was shown to increase the phagocytic activity of macrophages. A tendency of the fraction of phagocytic cells, the phagocytic index, and the index of phagocytosis completeness to increase was observed after its administration.

The basic laws governing phase separation in solutions of the synthetic polyampholytes formed by acrylic acid and 2-methyl-5-vinylpyridine have been studied. A reversible equilibrium transition from true solution to a polymeric dispersion is observed when the pH of the medium or the polymer concentration is changed. The pH region for phase separation of solutions of the polyampholytes is determined by the composition and compositional non-uniformity of the copolymer but it does not depend on the molecular-mass distribution. Structure-formation occurs above a critical polymer concentration, whose value depends on the pH of the medium and the copolymer's composition.

Copolymers of 2-methyl-5-vinylpyridine with acrylic acid have been studied by spectrophotometric titration in the UV region. It was found that the basic strength of the methylvinylpyridine groups increases as the proportion of acrylic acid units in the copolymer is increased, and the molar extinction coefficient, e, of these groups varies as the composition of the copolymer is varied. It is suggested that the change in the coefficient is brought about by change in the intramolecular distribution of the units in the copolymer.

The molecular and compositional heterogeneity of polyampholytes formed by acrylic acid and 2-methyl-5-vinylpyridine having various compositions and molecular masses have been assessed by spectroturbidimetric titration. Fractionation of the copolymers has been carried out in the system methanol-toluene. It has been established that, in the system methanol-diethyl ether, precipitation of the copolymers occurs principally with respect to composition and, in the system methanol-toluene, with respect to molecular mass.

Strongly basic anion exchange membranes were prepared by the radical copolymerization of chloromethylstyrene and 2-methyl-5-vinylpyridine. The formation of a three-dimensional structure and the presence of the quarternary pyridinium group were confirmed by infrared spectrum analysis and its strongly basic anion exchange properties. Their electrochemical properties and morphology were compared with those of the anion exchange membranes prepared from chloromethylstyrene-divinylbenzene and 2-methyl-5-vinylpyridine-divinylbenzene. The chloromethylstyrene-2-methyl-5-vinylpyridine membranes were proved to have larger anion exchange capacity, smaller electric resistance, larger water content, and higher permeability than the chloromethylstyrene-divinylbenzene and 2-methyl-5-vinylpyridine-divinylbenzene membranes. Also, the membranes have heterogeneity in the cross-linking structure.

The emulsion polymerization of 2-methyl-5-vinylpyridine (MVP) initiated by potassium persulphate in the presence of two anionic emulsifiers, sodium lauryl sulphate (NaLS) and sodium oleate, was investigated. The effects of persulphate and emulsifier concentration on the rate of polymerization are not those predictable on the basis of the theories of Harkins and Smith-Ewart. MVP polymerizes with a high rate in water solution and in emulsion even in the absence of emulsifier. A few emulsion polymerizations carried out with various NaLS concentrations near the critical micelle concentration showed that the presence of emulsifier in micellar form does not substantially increase the rate of polymerization, as predicted by the above theories. The behaviour of MVP is probably related to its moderate water solubility, which is 1·04 per cent by weight at 60°. Some experiments with seeded latexes confirmed that the water phase plays a predominant is not exclusive role as locus of polymerization.

In previous communications [1, 2] it was shown that polyampholytes based on two unsaturated, stereo-isomeric acids (maleic and fumaric) and 2-methyl-5-vinylpyridine are substantially different in their behaviour in titration. This was associated with the different spatial configurations of the carboxyl groups in these copolymers. Another important feature of polyampholytes of this type, also associated with the use of an ethylene-1,2-dicarboxylic acid as one of the comonomers, is that the acidic component units in the copolymer will alternate with a definite number of units of the basic component. The purpose of the present work was to extend the study of the behaviour of these polyampholytes in potentiometric titration. In contrast to the earlier work attention here was directed mainly to study of the effect of change in the ratio of acidic and basic groups in the copolymers on their behaviour in titration.

1. I. P. LOSEV, O. V. SMIRNOVA and Ye. V. KOROVINA, Vysokomol. soyed. 5: 1941, 1963 2. S. B. YEROFEYEVA, Dissertation, 1963 3. EL SAID ALI KKASAN, Dissertation, 1964 4. O. V. SMIRNOVA, EL SAID ALI KHASAN, I. P. LOSEV and G. S. KOLESNIKOV, Vysokomol. soyed. 7: 503, 1965 5. J. VAN-BRAUN, Liebig's Ann. Chem. 472: 1, 1929 6. E. KHORVAT, Dissertation, 1961 7. G. S. KOLESNIKOV, EL SAID ALI KHASAN and O. V. SMIRNOVA, Vysokomol. soyed. 7: 129, 1965

A fractionation of an acrylonitrile-2-methyl-5-vinylpyridine copolymer with respect to composition and molecular weight has been carried out by the fractional precipitation method. The distribution of the copolymer with respect to composition has a bimodal character, which may exert an effect on the properties of solutions and fibres.

1,3-Bis(dimethylamino)-2-(5′-vinyl-2′-pyridyl)propane and 2-(β-dimethylaminoethyl)-5-vinylpyridine were prepared by the aminomethylation of 2-methyl-5-vinylpyridine. These Mannich bases have been transformed into 1-dimethylamino-2-(5′-vinyl-2′-pyridyl)-1-propene and 2,5-divinylpyridine by the decomposition of their quaternary salts.