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Propylene Oxide Polymerization in the Presence of Layered Double Hydroxides

Abstract

Propylene oxide polymerization in the presence of layered double hydroxides with different concentration of basic sites on their surface has been studied. It is shown that the polymerization can be catalyzed by both basic and acidic sites. On the basis of kinetic experiments the mechanisms of reaction undergoing were proposed.

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Formation of environmentally friendly chloroorganic compounds technology by sewage and by-products utilization

Formation of environmentally friendly chloroorganic compounds technology by sewage and by-products utilization

The processes presented in the study enables the separation and disposal of the chloroorganic compounds as by-products from the vinyl chloride plant by using the dichlorethane method and also from the production of propylene oxide by the chlorohydrine method. The integrated purification method of steam stripping and adsorption onto activated carbon allows a complete removal and recovery of the chloroorganic compounds from waste water. Waste distillation fraction is formed during the production of vinyl chloride. 1,1,2-trichloroethane separated from the above fraction, can be processed to vinylidene chloride and further to 1,1,1-trichloroethane. 2,3-Dichloropropene, 2-chloroallyl alcohol, 2-chloroallylamine, 2-chlorothioallyl alcohol or bis(2-chloroallylamine) can be obtained from 1,2,3-trichloropropane. In the propylene oxide plant the waste 1,2-dichloropropane is formed, which can be ammonolysed to 1,2-diaminopropane or used for the production of β-methyltaurine. Other chloroorganic compounds are subjected to chlorinolysis which results in the following compounds: perchloroethylene, tetrachloromethane, hexachloroethane, haxachlorobutadiene and hexachlorobenzene. The substitution of the milk of lime by the soda lye solution during the saponification of chlorohydrine eliminates the formation of the CaCl2 waste.

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Direct synthesis of dimethyl carbonate and propylene glycol using potassium bicarbonate as catalyst in supercritical CO2

, epoxides, and methanol using heterogeneous basic metal oxide catalysts with high activity and selectivity. Appl. Catal. A: Gen. 219 (1-2), 259-266. DOI: 10.1016/S0926-860X(01)00698-6. 18. Chang, Y.H., Jiang, T., Han, B.X., Liu, Z.M., Wu, W.Z., Gao, L., Li, J.C., Gao, H.X., Zhao, G.Y. & Huang, J. (2004). One-pot synthesis of dimethyl carbonate and glycols from supercritical CO2, ethylene oxide or propylene oxide, and methanol. Appl. Catal. A: Gen. 263 (2), 179-186. DOI: 10.1016/j.apcata.2003.12.012. 19. Fan, B., Qu, B., Chen, Q.C., Wen, Y

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Soft-templating synthesis of nanoporous carbons with incorporated alumina nanoparticles

Soft-templating synthesis of nanoporous carbons with incorporated alumina nanoparticles

Soft-templated microporous-mesoporous carbons with embedded alumina nanoparticles were synthesized using resorcinol and formaldehyde as carbon precursors, different inorganic acids as a catalyst and poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymer as a soft template. The carbons studied have very good adsorption properties such as high specific surface area, uniform pore size distribution and a large total pore volume. The choice of catalyst seems to play an important role for the incorporation of aluminum species to the carbon framework, which after thermal treatment form aluminum oxide nanoparticles. This simple approach seems to be very promising for the design of carbon-based materials for a broad range of applications.

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Multifunctional oligoetherols and polyurethane foams with carbazole ring

Abstract

A new method of preparation of multifunctional oligoetherols containing carbazole ring is presented. The oligoetherols were obtained in the reaction of 9-(2,3-epoxypropyl)carbazole with sorbitol and oxiranes like ethylene and propylene oxide. The structure of obtained oligoetherols was determined by IR, H-NMR and MALDI-ToF spectroscopies. Physical properties of the products render them good candidates for preparing polyurethane foams. The foams were obtained and their properties were examined. It has been found that the foams are rigid at room temperature and their apparent density was 50–70 kg/m3. The water uptake was low, maximum to 6.5 mass%. Obtained foams have high thermal resistance. Dynamic thermal analysis of these foams showed that 5% mass loss was initiated at 250–300°C, while temperature of 50% mass loss was 370–404°C. Concomitantly the increase of compression strength was observed.

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Utilization of waste chloroorganic compounds

Utilization of waste chloroorganic compounds

Efficient methods of utilization of waste chloroorganic compounds coming from waste water and the waste streams formed e.g. in the production of vinyl chloride by dichloroethane method and in the production of propylene oxide by chlorohydrin method have been presented. First the separation of chloroorganic wastes by the adsorption methods has been described in the article. Three valuable methods of chlorocompounds utilization have been then discussed. The first one is isomerization of 1,1,2-trichloroethane to 1,1,1-trichloroethane as the valuable product with less toxicity than a substrate. The second method is ammonolysis of waste 1,2-dichloropropane and 1,2,3-trichloropropane. The third described method is chlorolysis. This method can be used for the utilization of all types of waste chloroorganics.

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Topical and prospective processes of acetoxylation

. 2,345,134. Washington D. C.: U. S. Patent and Trademark Office. Sano, K., Maki, K. & Kamei H. (1991) US Patent No. 5,011,980. Washington D. C.: U. S. Patent and Trademark Office. Hiro, T., Sakurai, K. (2004). US Patent No. 6,743,955. Washington D. C.: U. S. Patent and Trademark Office. Lewandowski, G. & Milchert, E. (2000). Integrated production of propylene oxide, phenol and acetone. Przem. Chem. 79, 410-411. Milchert, E. (1994). Hydrogen peroxide method of

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Development and characterization of thermosensitive pluronic-based metronidazole in situ gelling formulations for vaginal application

. Qi, L. Li, C. Huang, W. Li and C. Wu, Optimization and physicochemical characterization of thermosensitive poloxamer gel containing puerarin for ophthalmic use, Chem. Pharm. Bull.   54 (2006) 1500-1507; DOI 10.1248/cpb.54.1500. A. Cabana, A. Ait-Kadi and J. Juhasz, Study of the gelation process of polyethylene oxide-poly-propylene oxide-polyethylene oxide copolymer (poloxamer 407) aqueous solutions, J. Colloid Interface Sci.   190 (1997) 307-312; DOI: 10.1006/jcis.1997.4880. N. Jain, V. Aswal, P. Goyal and P

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Determination of Selected Volatiles in Cigarette Mainstream Smoke. The CORESTA 2008 Joint Experiment

determination of organic compounds in the gas phase of mainstream cigarette smoke; CORESTA Conference (2002) September, New Orleans Paper ST29. 6. Dong, J-Z: Simultaneous determination of 1,3-buta-diene, ethylene oxide, vinyl chloride, propylene oxide, acrylonitrile, benzene and isoprene in mainstream vapour phase cigarette smoke; Tobacco Science Research Conference, (2008), Nashville, 21-24 September Paper 42. 7. Health Canada: Determination of 1,3-butadiene, iso-prene, acrylonitrile, benzene and toluene in mainstream

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Effect of Pluronics and surfactant adsorption onto dolomite suspension zeta potential and stability

coadsorption of sodium dodecyl sulfate and poly(ethylene oxide)- b-poly(propylene oxide)-b-poly(ethylene oxide) triblock copolymer to silica, Langmuir, 17, 883-890, (2001). [15] D. Tsurumi, T. Yoshimura, K. Esumi, Adsolubilization of 2-naphtol into adsorbed layer of PEO-PPO-PEO triblock copolymers on hydrophilic silica, J. Colloid Inter.Sci., 297, 565-469, (2006). [16] S. J. Zhang, S. Lee, J. W. Lee, Does SDS micellize under methane hydrate-forming conditions below the normal Krafft point, J. Colloid Inter. Sci., 315, 313-318, (2007

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