D-Propylene oxide

Extensive studies of stereoselective polymerization of epoxides were carried out by Tsuruta et al.21 s. Copolymerization of a racemic mixture of propylene oxide with a diethylzinc-methanol catalyst yielded a crystalline polymer, which was resolved into optically active polymers216 217. Asymmetric selective polymerization of d-propylene oxide from a racemic mixture occurs with asymmetric catalysts such as diethyzinc- (+) bomeol218. This reaction is explained by the asymmetric adsorption of monomers onto the enantiomorphic catalyst site219. Furukawa220 compared the selectivities of asymmetric catalysts composed of diethylzinc amino acid combinations and attributed the selectivity to the bulkiness of the substituents in the amino acid. With propylene sulfide, excellent asymmetric selective polymerization was observed with a catalyst consisting of diethylzinc and a tertiary-butyl substituted a-glycol221,222. ... 

Fig. 11. Complex piezoelectric strain constant (20 Hz), complex Young s modulus (30 Hz), and complex dielectric constant (1kHz) of uniaxially drawn poly(D-propylene oxide) film plotted against temperature. Draw-ratio = 1.5. Degree of crystallinity=40%. Drawn after Furukawa and Fukada [Nature 221,1235 (1969)] by permission of Macmillan (Journals) Ltd.

Polymer Poly(D- propylene oxide) Cellulose triacetate Cellulose diacetate Polyfy-methyl L-glutamate) (a-helix)... 

Landau, R., Brown, D Russell, J.L., Kollar, J Epoxidation of Olefins, presented at Symposium on New Concepts and Techniques in Oxidation of Hydrocarbons, 7th World Petroleum Congress, Mexico City, April 1967 Landau, R., Sullivan, G.A., Brown, D., Propylene Oxide by Co-Product Processes, C/iem/pc/i, Oct. I979, p. 602... 

Bloor D M, Wan-Yunis W M Z, Wan-Badhi W A, Li Y, Hoizwarth J F and Wyn-Jones E 1995 Equilibrium and kinetio studies assooiated with the binding of sodium dodeoyl sulfate to the polymers poly(propylene oxide) and ethyl-(hydroxyethyl)oellulose Langmuir 3395-400... 

These products are characterized in terms of moles of substitution (MS) rather than DS. MS is used because the reaction of an ethylene oxide or propylene oxide molecule with ceUulose leads to the formation of a new hydroxyl group with which another alkylene oxide molecule can react to form an oligomeric side chain. Therefore, theoreticaUy, there is no limit to the moles of substituent that can be added to each D-glucopyranosyl unit. MS denotes the average number of moles of alkylene oxide that has reacted per D-glucopyranosyl unit. Because starch is usuaUy derivatized to a considerably lesser degree than is ceUulose, formation of substituent poly(alkylene oxide) chains does not usuaUy occur when starch is hydroxyalkylated and DS = MS. 

A suspension of 37.3 g (0.1 mol) of 7/3-amino-3-methoxy-3-cephem-4-carboxylic acid hydrochloride dioxanate in 500 ml methylene chloride is stirred for 15 minutes at room temperature under an argon atmosphere and treated with 57.2 ml (0.23 mol) of bis-(trimethylsilyl)-acetamide. After 45 minutes the faintly yellow slightly turbid solution is cooled to 0°C and treated within 10 minutes with 31.2 g (0.15 mol) of D-Ct-amino-Ct-d, 4-cyclohexadienyl (acetyl chloride hydrochloride. Thirty minutes thereafter 15 ml (about 0.21 mol) of propylene oxide is added and the mixture is further stirred for 1 hour at 0°C. A cooled mixture of 20 ml of absolute methanol in 200 ml of methylene chloride is added within 30 minutes, after another 30 minutes the precipitate is filtered off under exclusion of moisture, washed with methylene chloride and dried under reduced pressure at room temperature. The obtained hygroscopic crystals of the hydrochloride of 7j3-[D-a-(1,4-cyclohexadienyl)acetylamino] -... 

A way to anh-configurated a-amino-/ -hydroxycarboxylic acids is opened by the aldol addition of oxazolidine amides 7a and 7b. The method1061 is illustrated by a synthesis of (2R,3R)-p-hydroxyleucine (9) which is available from the major diastereomeric adduct 8 (d.r. 92 8) upon successive treatment with 1 N HC1 (30 min). 5 N HCl (100 C, 12 h), and propylene oxide (reflux in ethanol, 30 min). 

Propanediol (1,2-Propylene glycol, 1,2-Dihydroxy propane, Methyl glycol). CH3.CHOH.CH2OH mw 76.09 colorl, viscous, stable, hygr liq bp 187.3°, d 1.0381g/cc at 20/20° RI 1.4293 at 27° fl pt (open cup) 210°F autoignition temp 780°F. Misc with w, ales, and many org solvents in all proportions. Can be prepd by hydration of propylene oxide. On nitration it yields the exp] 1,2-Propanediol Dinitrate (see below)... 

Dragunski, D. C. and PawHcka A. (2001). Preparation and characterization of starch Grafted with Toluene Poly (propylene oxide) diisocyanate. Mater. Res., 4, 77-81. 

Carcinogenic compounds, 9 448 aromatic amine, 9 450 in dye production, 9 296 Carcinogenic elements, in ferrites, 11 59 Carcinogenicity. See also Cancer of acetaldehyde, 25 561 classification scheme for, 13 311 of herbicides, 13 311 hydrazine, 13 590-591 methanol, 16 314 of propylene oxide, 20 811 testing, 25 221-223 of 2,4-D, 13 315 Carcinogenic potential, 25 222 Carcinogenic risk, of nickel compounds, 17 120... 

Hydrolyzes in water forming l-chloro-2,3-hydroxypropane which may hydrolyze forming HCl and the intermediate l-hydroxy-2,3-propylene oxide or l-chloro-2,3-hydroxypropane. The oxide may continue to hydrolyze forming glycerol (Kollig, 1993). The estimated half-life for this reaction at 20 °C and pH 7 is 8.2 d (Mabey and Mill, 1978). 

Biological. Bridid et al. (1979) reported BOD and COD values of 0.17 and 1.77 g/g using filtered effluent from a biological sanitary waste treatment plant. These values were determined using a standard dilution method at 20 °C for a 5 d period. When a sewage seed was used in a separate screening test, a BOD value of 0.20 g/g was obtained. The ThOD for propylene oxide is... 

Chemical/Physical. The reported hydrolysis half-life for the conversion of propylene oxide to 1,2-propanediol in water at 25 °C and pH 7 is 14.6 d (Mabey and Mill, 1978). The second-order hydrolysis rate constant of propylene oxide in 3.98 mM perchloric acid and 36.3 °C is 0.124/M-sec (Kirkovsky et ah, 1998). 

Chisholm MH, Navarro-Llobet D (2002) Poly(propylene carbonate). 1. More about poly (propylene carbonate) formed from the copolymerization of propylene oxide and carbon dioxide employing a zinc glutarate catalyst. Macromolecules 35(6) 6494—6504... 

Liu Y, Huang K, Peng D, Wu H (2006) Synthesis, characterization and hydrolysis of an aliphatic polycarbonate by terpolymerization of carbon dioxide, propylene oxide and maleic anhydride. Polymer 47(26) 8453-8461... 

Wang JT, Shu D, Xiao M, Meng YZ (2006) Copolymerization of carbon dioxide and propylene oxide using zinc adipate as catalyst. J Appl Polym Sci 99 200-206... 

Kestenbaum H, de Oliveira AL, Schmidt W, Schiith F, Ehrfeld W, Gebauer K, Lowe H, Richter T, Lebiedz D, Untiedt I, Ziichner H (2002) Ind Eng Chem Res 41 710-719 Devanney MT, Kumamoto T (2009) Propylene oxide. SRI Consulting, Menlo Park, CA. Available at http //www.sriconsulting.eom/CEH/Public/Reports/690.8000. Accessed 30 May 2011... 

Temperature Programmed Reaction. Examination of another redox system, propylene oxidation on M0O3, provides further insight. It is well accepted that propylene oxidation on molybdenum-based catalysts proceeds through formation of allylic intermediates. From isotopic studies it has been demonstrated that formation of the allylic intermediate is rate-determining (H/D effect), and that a symmetric allylic species is formed ( C labelling). 

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