New catalyst systems for the polymerization of acetylene

The catalytic activities of WCI₆Ph₄Sn, MoCl₅Ph₄Sn and tetrabenzyltitanium were examined in the polymerization of acetylene. The structure, morphology and electrical conductivity of the doped and non doped polyacetylene were also studied.     

Corundum hydraulically hardening rammed compounds with a reduced grain size

Conclusions The production and use of rammed hydraulically hardening corundum compounds with different maximum grain sizes (from 1 to 7 mm) permits intermediate repairs of the linings of ladles of a steel ladle treatment unit, increasing their life.It is possible to determine the quantity of binder for obtaining the maximum strength by calculation by use of the coefficient of optimization, which is the portion of binder required per unit of specific surface of the mixture of filler grains. For the corundum hydraulically hardening compounds the optimum value of this coefficient is 0.8–1.2.Translated from Ogneupory, No. 2, pp. 40–43, February, 1987.     

Platinum particle size effect on the oxidative dehydrogenation of aqueous ethanol

The effect of the platinum particle size was investigated for the catalytic oxidative dehydrogenation of aqueous ethanol to ethanal at a temperature of 303 K, an ethanol concentration of 260 mol m^–3, a partial oxygen pressure 60 kPa, a pH of 9, and an ethanal and ethanoate concentration of 20 mol m^–3. A particle size effect on the turnover frequency was observed but only for particle sizes smaller than 2 nm. Hence, the reaction shows a limited structure sensitivity.     

PMMA‐modified divinylester/styrene resins: Phase diagrams and morphologies

Binary and ternary experimental cloud‐point curves (CPCs) for systems formulated with a low molar mass synthesized divinylester (DVE) resin, styrene (St), and poly(methyl methacrylate) (PMMA) were determined. The CPCs results were analyzed with the Flory–Huggins (F‐H) thermodynamic model taking into account the polydispersity of the DVE and PMMA components, to calculate the different binary interaction parameters and their temperature dependences. The St‐DVE system is miscible in all the composition range and down to the crystallization temperature of the St; therefore, the interaction parameter expression reported for a higher molar mass DVE was adapted. The interaction parameters obtained were used to calculate the phase diagrams of the St‐PMMA and the DVE‐PMMA binary systems and that of the St‐DVE‐PMMA ternary system at three different temperatures. Quasiternary phase diagrams show liquid–liquid partial miscibility of the St‐PMMA and DVE‐PMMA pairs. At room temperature, the St‐DVE‐PMMA system is miscible at all compositions. Final morphologies of PMMA‐modified cured St‐DVE materials were generated by polymerization‐induced phase separation (PIPS) mechanism from initial homogeneous mixtures. SEM and TEM micrographs were obtained to analyze the generated final morphologies, which showed a direct correlation with the initial miscibility of the system. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4539–4549, 2006     

Reciprocating flow ion exchange part II: Application to saline water softening

The “hardness” components in sea water can be considerably reduced by means of a new economical fixed bed technique called “Reciprocating Flow Ion Exchange”, when used in conjunction with a closed cycle exchanger-evaporator system. Removal of 87.9% of the calcium and 54.5% of the magnesium in sea water has been obtained with an overall flow rate of 5.0 U. S. g. p. m./sq. ft. Results from bench scale and a 5,000 g. p. d. pilot plant were identical. The virtually continuous cyclic steady-state process requires a small amount of exchanger (0.5 to 2% of the usual ion exchange methods, such as conventional fixed beds or fluidized beds). The effects of variation in operating parameters are discussed.     

Refractories for lining mobile mixers

Conclusions New and effective refractories have been developed whose physicotechnical and working parameters are better than those of existing Soviet and foreign materials. Commercial production of them has been organized.MKFU-83 and KKFU-76 refractories increase mixer lining resistance by substantial factors and reduce the number of repair cycles and the material and labor costs, while increasing the metal output. The refractories are recommended for use in steel-melting processes (electric furnaces and buckets).Translated from Ogneupory, No. 2, pp. 24–26, February, 1991.     

Periclase —spinel products from magnesite powder with high alumina content

Conclusions Periclase-spinel articles with low contents of chromite made from magnesite powder containing magnesia-alumina spinel have a high range of physicochemical properties (except spalling resistance) and completely satisfy the requirements in service for the roofs of open-hearth and walls of electric steel-melting furnaces.With an increase in the content of magnesite in the fine constituent, it is possible to obtain products of the same quality from magnesite powder with a high porosity (up to 20–23%).The change in ratio of chrome spinel and magnesia-aluminous spinel in the periclase-spinel articles toward a certain increase in the latter is worthy of attention and requires further investigation.Translated from Ogneupory, No. 2, pp. 11–15, February, 1966.     

Copper Complexes Obtained from the Schiff Base of Quinoline-2-Aldehyde and Aliphatic Diamines

Schiff base bis (2— quinolidene)- diamine gives a purple-red complex with copper ions with a λ_max at 530 mμ. The optimum pH for production of this complex is approximately 9.5. None of the metallic ions of the analytical groups II and III give rise to red complexes with the above Schiff base. Manganous (Mn²⁺) and stannous (Sn²⁺)ions as well as reducing agents such as hydrazine or hydroxylamine exert a catalytic effect on the rate of formation of these copper complexes. The thermal stability of the copper complex formed from the Schiff bases (2-quinoline-aldehyde with NH₂-(CH₂)_n-NH₂) is greater for diamine for which n = 4–6 than for n = 2–3.