Synthesis of polymers by using divalent metal salts of mono(hydroxyethyl) phthalate: Metal-containing polyurethanes

As difunctional compounds containing an ionic bond in the molecule, divalent metal salts (I) of mono(hydroxyethyl) phthalate were prepared in high purity and high yield. Mg and Ca were selected as divalent metal. Metal-containing polyurethanes containing ionic links in the main chain were synthesized by the polyaddition reaction of I or, I–glycols with diisocyanates. The polyurethane obtained were glassy materials or white powders, depending on the species of diisocyanates and glycols. Close agreement between observed and calculated values of metal content of the polyurethanes were obtained. The viscosities (in dimethyl-formamide) of the polyurethanes decreased markedly with increasing of metal content. Moreover, the decomposition temperatures were lowered by introduction of metals into the polyurethanes. However, the decomposition rates of metal-containing polyurethanes were lower than those of polyurethanes not containing metal.     

Synthesis of polyesters by using divalent metal salts of monohydroxyethyl phthalate: Metal-containing polyesters from such metal salts,anhydride, and epoxide

Synthesis of metal-containing polyesters by reactions of the divalent metal salts of monohydroxyethyl phthalate with phthalic anhydride and epoxide were investigated. It was found that the metal carboxylate groups of these metal salts catalyze the above reactions. These reactions were further studied in model reactions with the use of the Ca salt of monoethyl phthalate. Products obtained were linear metal-containing polyesters containing ionic links in the main chain; they were yellow or slightly yellow glassy materials; yields were generally high. Molecular weights obtained by the end-group analyses were generally low; with increase in content of the metal salts in the feed the molecular weight of the polyesters decreased. Inherent viscosities (in DMF at 30°C) of the metal-containing polyesters were low, ranging from 0.033 to 0.052. Elemental analyses are generally in good agreement with the calculated values. Thermogravimetric analyses of the polyesters were also discussed.     

Synthesis of polymers by using divalent metal salts of mono(hydroxyethyl) phthalate: Metal-containing polyurethane-ureas

A series of metal-containing polyurethane-ureas containing ionic links in the main chain was synthesized by the polyaddition reaction of hexamethylene diisocyanate with mixtures of metal salts of mono(hydroxyethyl) phthalate and bisureas containing two hydroxyl groups which were obtained from monoethanolamine and diisocyanates. The polyurethane-ureas obtained were generally yellowish powders or solids. Close agreement between observed and calculated values of metal content of the metal-containing polyurethane-ureas was obtained. The viscosities (in dimethylformamide) of polyurethane-ureas decreased markedly with increase of metal content. Moreover, the decomposition temperatures were lowered a little by introducing metals into the polyurethane-ureas. Dimethylformamide, m-cresol, and dimethyl sulfoxide were comparatively good solvents for the metal-containing polyurethane-ureas; however, the polymers were insoluble in all other solvents.     

Properties of isocyanurate-type crosslinked polyurethanes

Polyurethane elastomers containing isocyanurate rings as crosslinking structure were prepared by crosslinking the prepolymers in N,N-dimethylformamide solution with sodium cyanide catalyst. Physical properties such as gel fraction, swelling ratio, density, glass transition temperature, Young's modulus, tensile strength, and elongation at break were measured. The effects of diisocyanate structure, the degree of crosslinking, and the crosslinking structure on the properties of polyurethanes were studied. The stress–strain curves of isocyanurate-type crosslinked polyurethanes prepared from poly(oxytetramethylene)glycol rose at lower extensions and gave higher tensile properties than those of triol-cured and diamine-cured polyurethanes. The observed high tensile properties were attributed to the rigid crosslinking structure of isocyanurate ring.     

Metal-containing crosslinked polyester resins by combined polyesterification and polymerization of curable mixtures based on divalent metal salts of mono(hydroxyethyl)phthalate

Preparations of metal-containing crosslinked polyester resins based on divalent metal salts of mono(hydroxyethyl)phthalate were investigated by the cure, by combined polyesterification and polymerization, of curable mixtures prepared from above metal salts, maleic anhydride, glycidyl methacrylate, and methyl methacrylate. The curable mixtures containing Ca showed lower viscosity than those containing Mg. They were subjected to curing reactions in the presence of peroxide and under photoirradiation, respectively. In the cure, polyesterification and polymerization proceeded simultaneously smoothly, giving metal-containing cured resins. Generally, the peroxide-cured resins showed better physical properties than the photo-cured resins. Especially, the former resins with high metal content showed high compressive strength and Rockwell hardness. Further, resistance to chemical attack and boiling water and thermal behavior are also discussed.     

The kinetics and mechanisms of thermal degradation of some divalent metal salts of mono(hydroxyethyl) phthalate

The thermal decomposition of lead and manganese salts of mono(hydroxyethyl) phthalate was studied by thermogravimetry and differential scanning calorimetry. The kinetic parameters for the various stages of decomposition of these salts were calculated by different methods and mechanisms are proposed to explain the results.     

Polymers based on divalent metal salts of p-aminobenzoic acid: a review

Divalent metal salts of p-aminobenzoic acid are useful starting materials for syntheses of ionic polymers into which metal is firmly incorporated. This paper is a review of a series of polymers that have been prepared using the metal salts. The salts can react with compounds having functional groups capable of reacting with amino groups. By polyaddition reactions of the salt–aromatic diamine with diisocyanate, and with isocynate-terminated adducts of diisocyanate and dialkylene glycol, halatotelechelic polyureas and polyurethane-ureas are obtained. By amine–epoxy reactions of systems of the salt–diamine–bisepoxide, and addition reactions of systems of the salt–dicarboxylic acid anhydride–bisepoxide, metal-containing cured resins are obtained. In this case, the metal carboxylate groups of the salts have catalytic activities for the curing reactions, and also for etherification of epoxy groups as a side reaction. Therefore, crosslinking of bisepoxide with the salts, and with adducts of the salts and the anhydride, has been investigated by taking advantage of the catalytic activity of the metal carboxylate groups for the etherification of epoxy groups. Interestingly, the metal-containing cured resins obtained by crosslinking by etherification of bisepoxide with the adducts show very high impact strength. © 1997 John Wiley & Sons, Ltd.     

Thermoelastic properties of crosslinked polyurethanes

Thermoelastic (stress–temperature) measurements in elongation have been carried out on polyurethane elastomers obtained from poly(ethylene adipate), poly(ethylene maleate), poly(ethylene glycol), and 4,4′-diphenylmethane diisocyanate. The elastomers were crosslinked by an excess of diisocynate and some of them were additionally crosslinked by dicumyl peroxide. Values of the temperature coefficient d ln r /dT of the unperturbed dimensions of the network chains and the fraction f_e/f of the stress, which is due to energetic effects, were calculated from measurements of unswollen samples and samples swollen in benzene to a constant volume fraction ν₂ of about 0.6. The coefficient d ln r /dT and the ratio f_e/f for unswollen samples were positive but dependent on the extension ratio α and crosslinking density. The f_e/f ratio displayed a tendency to decrease with increasing α and this decrease was smaller for elastomers of higher crosslinking density. Additional crosslinking due to dicumyl peroxide reduced the dependence of f_e/f on α. Swollen samples had lower positive values of f_e/f; which were somewhat independent of α and crosslinking density. Departures from the molecular theories of rubberlike elasticity are explained by intermolecular effects, which, in general, are influenced by crosslinking.     

Thermogravimetric study of some divalent metal chelate polymers of dithiooxamide

The thermal properties of polymeric chelates of dithiooxamide with divalent copper, cobalt, zinc and nickel have been investigated. The order of thermal stability is Ni>Co～Zn>Cu, which is the same as that observed for previously studied naphthazarin and rhodizonic acid chelates. The procedural decomposition temperatures indicate that the dithiooxamide chelates, which are not aromatic, are about as stable as the aromatic naphthazarin and rhodizonic acid chelates. Several unsuccessful attempts were made to prepare beryllium and manganese (II) chelates.     

Synthesis and rheology of methacrylic acid-ethyl acrylate crosslinked polymers

The rheological behaviour of methacrylic acid-ethyl acrylate copolymers (MAA 61.9–78.5 mol%) and terpolymers with two crosslinking agents, i.e. ethylene glycol dimethacrylate (EGDM, 0.23–4.83 mol%) or N, N′-methylene bisacrylamide (MBAM, 0.29–1.48 mol%) has been studied. The effect of pH, shear rate, solid content of the solution, and the addition of electrolyte on the viscosity has been reported. As the viscosity is a function of neutralization of carboxylic acid groups, it was found to be highly dependent on pH. Addition of electrolytes (0.5–1.5%) led to a drastic drop in the viscosity. The influence of different crosslinking agents on the viscosity was also studied and N, N′-methylene bisacrylamide was found to be more efficient than ethylene glycol dimethacrylate. The gel content of the crosslinked polymers was determined to obtain an idea of the degree of crosslinking of the polymers.     

Synthesis of phosphorus-containing polyurethanes without use of isocyanates

Phosphorus-containing polyurethanes were synthesized by reacting phosphonic acid diesters (RO)₂P(O)X (X = H, CH₃, Ph) with hydroxycarbamates. These phosphorus-containing polyurethanes were characterized by a combination of molecular-weight determination (GPC) and NMR spectroscopy. The thermal stability of the polymers was evaluated by a combination of TGA and DTA techniques. These polymers are readily soluble in highly polar solvents like DMF and DMSO. The phosphorus-containing polyurethanes are water soluble. © 1996 John Wiley & Sons, Inc.     

Study the electrical conductivity of crosslinked polyester doped with different metal salts

Three crosslinked polymers were prepared via condensation polymerization between triethanolamine and glycerol [(25:75%), (50:50%) and (0:100%) (G:TEA)] with maleic anhydride which produced polymers I, II and III consequently. All the prepared polymers were doped with metal salts (CuCl₂, NiCl₂ and FeCl₂). D.C. conductivity was measured in the temperature range of (298–373 K), the result showed that the electrical conductivity increased several orders of magnitude with increasing temperature, the activation energy decreased with increasing conductivity. A.C. measurement is used to calculate the dielectric constant for the polymers in both pure and doped state.     

Synthesis of polyacrylamide/polyurethane hydrogels by latex IPN and AB crosslinked polymers

Interpenetrating polymer network (IPN) and AB crosslinked polymer (ABCP) hydrogels composed of polyacrylamide (PAAm) and polyurethane (PU) have been synthesized as function of degree of polymerization of PU prepolymer, crosslink density of PAAm domain, and gel composition. Both PAAm/PU IPN and ABCP gels gave synergistic effects in terms of density showing positive deviation from the linear additivity. As a result of this, the strength of swollen gel increased over approximately two times with a small addition of flexible PU (10–20%) to the rigid PAAm.     

Tetracyanomanganate(II) and its salts of divalent first-row transition metal ions

The first known paramagnetic, tetrahedral cyanide complex, [Mn(II)(CN)(4)](2)(-), is formed by the photoinduced decomposition of [Mn(IV)(CN)(6)](2)(-) in nonaqueous solutions or by thermal decomposition in the solid state. In acetonitrile or dichloromethane, photoexcitation into the ligand-to-metal charge transfer band (lambda(max) = 25 700 cm(-1), epsilon = 3700 cm(-1) M(-1)) causes the homolytic cleavage of cyanide radicals and reduction of Mn(IV). Free cyanide in dichloromethane leads to the isolation of polycyanide oligomers such as [C(12)N(12)](2)(-) and [C(4)N(4)](-), which was crystallographically characterized as the PPN(+) salt C(40)H(30)N(5)P(2): monoclinic space group = I2/a, a = 18.6314(2) A, b = 9.1926(1) A, c = 20.8006(1), beta =106.176(2) degrees, Z = 4]. In the solid state Mn(IV)-CN bond homolysis is thermally activated above 122 degrees C, according to differential scanning calorimetry measurements, leading to the reductive elimination of cyanogen. The [Mn(II)(CN)(4)](2-) ion has a dynamic solution behavior, as evidenced by its concentration-dependent electronic and electron paramagnetic spectra, that can be attributed to aggregation of the coordinatively and electronically unsaturated (four-coordinate, 13-electron) metal center. Due to dynamics and lability of [Mn(II)(CN)(4)](2-) in solution, its reaction with divalent first-row transition metal cations leads to the formation of lattice compounds with both tetrahedral and square planar local coordination geometries of the metal ions and multiple structural and cyano-linkage isomers. alpha-Mn(II)[Mn(II)(CN)(4)] has an interpenetrating sphalerite- or diamond-like network structure with a unit cell parameter of a = 6.123 A (P43m space group) while a beta-phase of this material has a noninterpenetrating disordered lattice containing tetrahedral [Mn(II)(CN)(4)](2-). Linkage isomerization or cyanide abstraction during formation results in alpha-Mn(II)[Co(II)(CN)(4)] and Mn(II)[Ni(II)(CN)(4)] lattice compounds, both containing square planar tetracyanometalate centers. alpha-Mn(II)[Co(II)(CN)(4)] is irreversibly transformed to its beta-phase in the solid state by heating to 135 degrees C, which causes a geometric isomerization of [Co(II)(CN)(4)](2)(-) from square planar (nu(CN) = 2114 cm(-1), S = (1)/(2)) to tetrahedral (nu(CN) = 2158 cm(-1), S = (3)/(2)) as evidenced by infrared and magnetic susceptibility measurements. Mn(II)[Ni(II)(CN)(4)] is the only phase formed with Ni(II) due to the high thermodynamic stability of square planar [Ni(II)(CN)(4)](2)(-).     

Model filled polymers. VIII. Synthesis of crosslinked polymeric beads by seed polymerization

Monodisperse crosslinked polystyrene (PS) and polymethacrylate (PMA) beads of sizes greater than 1 μm in diameter are prepared by particle nucleation onto pre-existing polymer seeds in a multistage emulsion polymerization, in the absence of emulsifier. An adequate seed number concentration, which decreases with increasing seed size, is necessary to achieve monodisperse beads. Monodisperse multicomposition beads are prepared by polymerizing styrene onto PMA seeds, but not by polymerizing methyl methacrylate onto PS seeds. Phase separation in growing seed particles or surface polymerization following free radical capture may lead to the formation of asymmetric shaped particles.     

Synthesis and characterization of triphenylmethylphosphonium transition metal salts

Triphenylmethylphosphonium salts, [PPh3Me]aMXn (M=Cu2+, Co2+, Mn2+, Ni2+ Fe3+ Pb2+ and Hg2+; X=Cl or I; a=1 or 2 and n=3 or 4) prepared by reacting PPh3MeX with the metal dihalide in EtOH sol-utions, have been characterized by electronic, Raman, far i.r. and Mo¨ssbaur spectra and by their magnetic properties as well as by elemental analyses. The copper complexes [PPh3Me]2CuCl4 and [PPh3Me]2Cu3Cl8 were characterized by X-ray crystallography and the structures are described. Powder diffraction patterns have shown that the cobalt and manganese tetrachloride complexes are isomorphous. Investigation by d.s.c. measurements showed that the complexes exhibit structural phase transitions.     

Synthesis and characterization of divalent metal complexes with bipyridylamide ligands

Reaction of N-(4-pyridyl)picolinamide (4-ppa), N-(4-pyridyl)nicotinamide (4-pna), N-(4-pyridyl)isonicotinamide (4-pina), and N-(2-pyridyl)isonicotinamide (2-pina) with divalent metal salts led to the formation of six new coordination complexes. The X-ray structure of [Zn(4-ppa)₂Cl₂] (1) shows a mononuclear structure with interesting intermolecular hydrogen bonding interactions. [Zn(4-pna)(OAc)₂]_n (2), Cu(4-pna)(OTf)₂(DMF)₂]_n (3), {[Zn(4-pina)(DMF)₄](OTf)₂}_n (4), {[Fe(4-pina)(DMF)₄](OTf)₂}_n (5), and [Cu(2-pina)(OTf)₂(DMF)₂]_n (6) are one-dimensional coordination polymers with conformational differences caused by the coordination donor disposition, which demonstrates the flexibility of the pyridylamide ligands in polymeric structures. Reflectance UV-visible spectra and thermal properties of the coordination polymers are also reported.     

Synthesis of some novel divalent transition metal complexes as antimicrobials

A novel series of transition metal complexes have been synthesized from the reaction of 5-((3-(methylthio)-5-(pyridin-4-yl)-4H- 1,2,4-triazol-4-ylamino)melhyl)quinolm-8-ol with transition metal salts.The structures of these compounds have been elucidated by elemental and spectral analysis.Furthermore,compounds were screened for in vitro antimicrobial activity against the representative panel of two Gram-positive and two Gram-negative bacteria and two strains of fungus.The various compounds show potent inhibitory action against test organisms.