Zh. A. Vnutskikh

Crystal structures of two copper(II) complexes with N,N-diethylbenzhydrazide

The copper(II) complexes with N,N-diethylbenzhydrazide, [Cu(C6H5CONHN(C2H5)2)]Cl2 (I) and Cu(C6H5CONN(C2H5)2)2 (II), have been studied by X-ray diffraction analysis. In the both compounds, the reactant acts as a bidentate (O, N(2)) ligand, forming five-membered chelate rings with copper. In cationic complex I, the O→Cu and N→Cu bond lengths are 1.954(2) and 2.070(3) Å, respectively, and the O(1)CuN(2) chelate angle is 81.89(10°. The Cl− ions are in the coordination sphere of copper (Cu-Cl, 2.1974(11) and 2.2178(10) Å). The chelate ring has an envelope conformation with the copper atom in the flap position. The coordination polyhedron of the copper atom is a strongly distorted tetrahedron. Neutral complex II is an inner complex salt. The reactant forms with copper two planar chelate rings. The Cu-O and N→Cu bond lengths are 1.8901(9) and 2.0175(11) Å, respectively, and the O(1)CuN(2) chelate cycle is 83.70(4)°. Complex II is planar, and the coordination polygon of the copper atom is a parallelogram. The thermal stability of complexes I and II has been studied.

Application of inorganic compounds at the thermal processing of polyvinylchloride

A review of publications on the effect of various inorganic additives (metals oxides, hydroxides, chlorides and carbonates) on the process of dehydrochlorination and pyrolysis at the thermal processing of polyvinylchloride (PVC). A decrease in temperature of the PVC dehydrochlorination step is noted at processing in the presence of chromium, iron, cobalt, copper and molybdenum oxides. Aluminum, titanium, circonium, cerium and lead oxides do not change temperature of beginning of PVC destruction. No effect noted of the oxides at the second step of PVC destruction.

Formation of polyurethane structural materials based on mixtures of oligoethers with different reactivities

Kinetics of the reaction of urethane formation from oligopolyols with primary and secondary hydroxy groups and the influence exerted on their interaction by products formed in the reaction of N,N,N′,N′-tetrakis-(-2-hydroxypropyl)-ethylenediamine with an isocyanate were studied. Samples of high-strength polyurethane composites based on mixtures of oligoetherpolyols and the oligomeric diamine were obtained. These samples approximately twice surpass in strength materials based on oligoepoxides. The working capacity of the samples under severe climatic conditions was demonstrated.

Properties of calcium fluoride-filled cross-linked plasticized polyurethane

Thermal and physicomechanical properties of plasticized polyurethane based on oligo(butadiene)diol prepolymer and oligoethertriol were examined as influenced by microdispersed calcium fluoride. Introduction of this filler substantially improved the physicomechanical properties of the polyurethane compositions.

Synthesis and antimicrobial activity of mono-and biquaternized derivatives of dipyridylethanes and dipyridylethylenes

A series of mono-and biquaternized derivatives of dipyridylethanes and dipyridylethylenes has been synthesized and characterized with respect to antimicrobial activity. The new compounds exhibit structure-dependent antimicrobial action on both Gram-negative (E. coli) and Gram-positive (St. aureus) bacterial species. Monoquaternized dipyridylethane and dipyridylethylene derivatives show a higher antimicrobial activity than compounds with two onium nitrogen atoms; derivatives of dipyridylethane are less active than the analogous derivatives of dipyridylethylene. A high antimicrobial activity (MIC ∼ 1 mg/ml) was observed for 1-[N-cetyl-(4-pyridinium)]-2-(4-pyridyl)ethylene.

Characteristics of polyether urethanes with mixed soft segments, prepared by two- and three-step procedures

A three-step procedure for preparing polyurethanes with mixed polyether segments was suggested. It involves preparation of the “inverse” prepolymer by the reaction of one of oligodiisocyanates with 1,4-butanediol taken in a double excess, followed by the reaction with the other oligodiisocyanate. Polyurethanes with alternating poly(tetramethylene oxide) and poly(propylene oxide) soft segments were prepared by this procedure. Such materials surpass polyurethanes prepared from a mixture of oligodiisocyanates in the strength and softening point of the hard phase. In contrast to poly(tetramethylene oxide) urethane, elastomers with mixed polyether segments do not crystallize.

Synthesis and antimicrobial activity of new mono-and biquaternized dipyridylethanes and dipyridylethylenes

A series of mono-and biquaternized derivatives of dipyridylethane and dipyridylethylenes were synthesized in order to study their antimicrobial activity (AMA) with respect to Gram-negative (E. coli) and Gram-positive (S. aureus) species. It is established that the antimicrobial activity depends on the nature of the radical on the nitrogen atom, the positions of the ethane and ethylene bridges between the rings relative to the onium nitrogen atoms, and the presence of conjugated systems between these atoms. The maximum AMA with respect to the indicated test microbe strains was observed for 1-(N-dodecylpyridin-4-yl)-2-(4-pyridyl)ethylene bromide (MIC 3.9 and 2.0 μg/mL, respectively).

Tetrablock Copolymers Based on Oligoether Diols, 2,4-toluene diisocyanate, Isophorone Diisocyanate, and Methylene-bis-о-chloroaniline

Tetrablock polyurethane ureas with mixed soft segments and dissimilar hard urethane urea blocks, based on oligo(propylene oxide)diol, oligo(tetramethylene oxide)diol, 2,4-toluene diisocyanate, isophorone diisocyanate, and methylene-bis-o-chloroaniline as a low-molecular-mass chain extender were synthesized and studied. The fragmentary ordering of the polymer chains of the new polyurethane urea was proved by rheokinetic data. The structure–property relationship for the polymer was found. The new polyurethane ureas surpass in the true strength the available diblock polyurethane ureas with poly(propylene oxide) soft segments by a factor of 1.5. The strength properties of the new tetrablock polyurethane ureas only weakly depend on the strain rate varied in the range 0.56–0.006 s–1.

Influence of the molecular mass of soft segments on the thermodynamic stability and physicomechanical properties of plasticized polyether urethane

The physicomechanical properties and thermodynamic stability of segmented polyether urethane containing poly(tetramethylene oxide) segments of different molecular masses (М ∼ 1000, 1400, 1950) and plasticized with di(2-ethylhexyl) sebacate were analyzed in relation to the molecular mass of the soft segments, and the glass transition point of the soft phase of the polymer was determined. Based on the results obtained, a rapid method was suggested for experimental determination of the osmotic pressure (up to ∼1000 kPa) in the polymer–plasticizer system. The possibilities of preparing thermodynamically stable plasticized materials of high strength (up to 22–26 MPa) with the glass transition point as low as–95 to–100°С were demonstrated.

Block copolymers with urethane and urethane-urea rigid blocks based on oligoesterdiisocyanate and a binary low-molecular hardener

The synthesis of block copolymers with oligoether soft segments, urethane and urethane–urea blocks based on oligoetherdiisocyanate and mixtures of low-molecular diamine and diol has been described. The dependence of the structure and properties of these materials on the hard block composition and regularities of their mechanical behavior in a wide range of stretching rates have been established. The advantages of the new materials compared to the traditional polyurethane ureas have been demonstrated.