Gulzhian I. Dzhardimalieva

Macromolecular metal carboxylates and their nanocomposites

Monomeric and Polymeric Carboxylic Acids.- Synthesis of Unsaturated Carboxylic Acid Salts.- Spectral Characteristics and Molecular Structure of Unsaturated Carboxylic Acid Salts.- Polymerization and Copolymerization of Salts of Unsaturated Carboxylic Acids.- Polymer-Analog Transformations in Reactions of Synthesis of Metal Macrocarboxylates.- Molecular and Structural Organization of Metal-Containing (Co)Polymers.- Properties and Basic Fields of Application of Metal-Containing Polymers.- Monomeric and Polymeric Metal Carboxylates as Precursors of Nanocomposite Materials.- Conclusion.

SYNTHESIS AND REACTIVITY OF METAL-CONTAINING MONOMERS. 47. SYNTHESIS AND STRUCTURE OF SALTS OF UNSATURATED DICARBOXYLIC ACIDS

Acid and neutral CoII, CuII, NiII, ZnII, FeII, and FeIII maleates, fumarates, and itaconates were obtained and characterized. The methods for their synthesis were optimized, and the valence state and coordination of metals were studied. CoII and FeII hydrogen maleates, CoII maleate, and CoII fumarate were examined by X-ray diffraction analysis. The ligands based on unsaturated dicarboxylic acids can be mono-, bi-, and tetradentate, which results in the formation of acid salts, chain and three-dimensional coordination polymers, whose double bond is not involved in the coordination. The strong antiferromagnetic exchange (μelf=1.41 and 0.34 μB at 290 and 80 K, respectively) was detected in CuII itaconate. Based on the data of Mössbauer spectroscopy, the partial reduction of FeIII to FeII during the synthesis of FeIII maleate was shown to occur: δFe=0.43 and 1.27 mm s−1, ΔEQ=0.57 and 3.13 mm s−1 and Γ=0.37 and 0.28 mm s−1 atT=298 K for FeIII and FeII, respectively.

The autowave modes of solid phase polymerization of metal-containing monomers in two- and three-dimensional fiberglass-filled matrices

The phenomenon of autowave (frontal) solid phase polymerization of metal-containing monomers based on metal-acrylamide complexes is considered. The comparison of the features of autowave processes realized in both the single-component matrices of the monomer and the matrices filled by the fiberglass materials is performed. The unstable regimes of the polymerization wave as well as the conditions for the stabilization of the flat front in the filled matrices are described. The peculiarities of the frontal regimes in the three- and two-dimensional media are studied. Some possibilities for using of autowave polymerization in the fabrication of the polymer-fiberglass composites and composition prepregs are discussed. (c) 1999 American Institute of Physics.

Polymer-matrix nanocomposite gas-sensing materials

A new approach has been proposed for producing nanocomposite gas-sensing materials: in situ preparation of a polymer matrix and metal sulfide or oxide nanoparticles through the frontal polymerization of Co(II), Cd(II), Zn(II) and Pb(II) acrylamide complexes. The composition and structure of the nanocomposites thus obtained have been determined using X-ray diffraction, scanning and transmission electron microscopy, and Raman spectroscopy. The nanocomposites have been tested as room-temperature liquefied petroleum gas sensors.

Frontal Polymerization of Metal-Containing Monomers: A Topical Review

The peculiarities of the frontal polymerization of metal-containing monomers containing acrylamide (AAm) complexes of transition metal nitrates, M(AAm)x(H2O)y(NO3)2 (M=Co, Ni, Fe, Cu, Zn, Cd, Ba), that are thermally initiated at 353–433 K are considered. It was found that nitrogen oxides (e.g., NO2, NO, N2O), which were formed by partial oxidation of the nitrate groups, were able to initiate the polymerization reaction. The reaction front and a self-sustained thermal wave were determined by structural-chemical and energy factors. The application of a self-propagating frontal polymerization to synthesize metal-containing copolymers was demonstrated. The constants of reactivity of the monomers (r1=0.63, r2=0.70) confirmed the statistical character of the copolymers obtained. Frontal polymerization of the AAm complexes that were filled by silica or glass powder was studied. Adding fillers stabilized the front and resulted in spatially uniform products. By following the controlled thermolysis of the metallopolymer or the controlled change of frontal polymerization into the burning regime lead to the formation of metallopolymer nanocomposites. The products were metal (or metal oxides) nano-scale particles that were stabilized by the polymer matrix that is formed.

Reactivity of metal-containing monomers

Thermal conversion of cobalt(II) maleate, CoC4H2O42H2O, (1) at 340–370 °C was studied. The composition of the products of pyrolysis was determined. The major solid-phase product of decomposition consists of nano-sized particles of CoO (sizes vary within narrow limits) stabilized by the polymeric matrix. Thermal conversions of CoII maleate involve dehydration, polymerization of dehydrated monomers, and decarboxylation of the resulting polymer.

Formation, Structure and Magnetic Properties of Polymer Matrix Nanocomposites Processed by Thermal Decomposition of the Fe(III)Co(II) Acrylate Complex

Structure and magnetic properties of polymer matrix nanocomposites, processed by pyrolysis of the Fe(III)Co(II) acrylate complex, were investigated. It was shown that thermal transformation of the complex studied consisted of three macrostages: dehydration, solid state polymerisation and decarboxylation of a metallopolymer form. The main products of the decomposition were nanoparticles stabilised by polymeric matrix. The crystalline phases, which were found in the fully processed material, were Fe3O4, CoFe2O4 and CoO. The mean crystallite size was 10nm. In the intermediate stages of the thermolysis iron was present in the forms of FeIII (trivalent low – spin iron), Fe2+(divalent high – spin iron) and Fe3O4. The hysteresis loops measured at temperatures below 200K were opened and shifted towards negative field. The coercivity and remanence showed room temperature values of 0.18T and 15.5mT, respectively.

Review: recent advances in the chemistry of metal chelate monomers

Abstract This review summarizes recent advances in the chemistry of metal chelate monomers. Depending on the character of bonding of the metal to the chelating fragment, metal chelate monomers are divided into four main types: molecular metal chelates, intracomplex compounds, macrocyclic complexes, and polynuclear metal chelates. The synthetic methodologies for preparing metal chelate monomers are systematized. Special attention is paid to the effect of a metal on both the polymerization transformations of the metal chelate monomers and properties of the products formed. The bibliography includes papers published after 2010.

Metal Chelate Monomers as Precursors of Polymeric Materials

The principal advances and problems of the preparation of polymeric materials based on metal chelate monomers containing metal chelate cycle and functionality are analysed. The data are systematized according to methods for preparing polymeric materials: homopolymerization, copolymerization, living and controlled polymerization, grafting polymerization, electropolymerization, polycondensation, as well as synthesis of dendrimers and hyperbranched polymers based on metal chelate monomers. Special attention is paid to the effect of a metal on both the synthesis mechanism and properties of the products formed. The principal applications of polymeric materials based on metal chelate monomers are considered.

Hybrid polymer-immobilized palladium nanoparticles: Preparation and catalytic properties

A new approach to the synthesis of mixed-type immobilized catalysts was developed: the frontal polymerization of a metal-containing monomer in the presence of a highly dispersed mineral support. The synthesis of an acrylamide complex of Pd(II) nitrate on the surface of SiO2, Al2O3, or C and its subsequent polymerization and reduction resulted in the formation of an organic-inorganic composite that included nanosized Pd particles stabilized by a polymer matrix and an inorganic support. The resulting hybrid nanocomposites are efficient and selective catalysts for the hydrogenation reactions of cyclohexene and alkene and acetylene alcohols.