Propylene glycol carbonate

The third type of reaction for polyester polyols synthesis is the ring opening polymerisation of cyclic esters, such as -caprolactone (reaction 8.4) or cyclic carbonates, such as ethylene glycol carbonate, propylene glycol carbonate, neopentyl glycol carbonate, etc., (reaction 8.5) initiated by diols (or polyols) and catalysed by specific catalysts [7, 16]. 

Poly(ethylene glycol-co-propylene glycol) carbon dioxide 2002DRO... 

Poly [(ethylene glycol) mono-dodecyl ether-()-propylene glycol] carbon dioxide HPPE 300-301... 

Poly(propylene glycol) carbon dioxide carbon dioxide 2000SAR 2007K1L... 

Silva, E.D. Dayoub, W Mignani, G. Raoul, Y Lemaire, M. Propylene Carbonate Synthesis from Propylene Glycol, Carbon dioxide and Benzonitrile by AlkaU Carbonate Catalysts. Catal. Comm. 2012,29, 58-62. 

Lactones are piepaied from formaldehyde and carbon monoxide by cyclocondensation with propylene glycol in the presence of a strong acid and a Cu(l) or Ag carbonyl catalyst (20). 

CycHc carbonates are made by treating 1,2-diols with dialkyl carbonates using an alkyl ammonium and tertiary amine catalyst. The combination of propylene glycol and dimethyl carbonate has been reported to result in a 98% yield of propylene carbonate (21). 

Propylene glycol, dipropylene glycol, and tripropylene glycol all have several isomeric forms. Propylene glycol has one asymmetric carbon and thus there are two enantiomers (R)-I,2-propanediol and (3)-1,2-propanediol. 1,3-Propanediol is a stmctural isomer. Dipropylene glycol exists in three stmctural forms and since each stmctural isomer has two asymmetric carbons there are four possible stereochemical isomers per stmcture or a total of twelve isomers. These twelve consist of four enantiomer pairs and two meso- compounds. Tripropylene glycol has four stmctural isomers and each stmctural isomer has... 

Other possible chemical synthesis routes for lactic acid include base-cataly2ed degradation of sugars oxidation of propylene glycol reaction of acetaldehyde, carbon monoxide, and water at elevated temperatures and pressures hydrolysis of chloropropionic acid (prepared by chlorination of propionic acid) nitric acid oxidation of propylene etc. None of these routes has led to a technically and economically viable process (6). 

In another method, phosgene is gradually passed into 1,2-propylene glycol (9). The chloroformate is washed, dried, and distilled at 266 Pa (2 mm Hg) and added slowly to a mixture of aHyl alcohol and pyridine below 15°C. The purified monomer 1,2-propylene glycol bis(aHyl carbonate) (C H O ) heated with lauroyl peroxide at 70°C gives a hard clear, polymer. 

Propylene oxide is also produced in Hquid-phase homogeneous oxidation reactions using various molybdenum-containing catalysts (209,210), cuprous oxide (211), rhenium compounds (212), or an organomonovalent gold(I) complex (213). Whereas gas-phase oxidation of propylene on silver catalysts results primarily in propylene oxide, water, and carbon dioxide as products, the Hquid-phase oxidation of propylene results in an array of oxidation products, such as propylene oxide, acrolein, propylene glycol, acetone, acetaldehyde, and others. 

Hydrolysis to Glycols. Ethylene chlorohydrin and propylene chlorohydrin may be hydrolyzed ia the presence of such bases as alkaU metal bicarbonates sodium hydroxide, and sodium carbonate (31—33). In water at 97°C, l-chloro-2-propanol forms acid, acetone, and propylene glycol [57-55-6] simultaneously the kinetics of production are first order ia each case, and the specific rate constants are nearly equal. The relative rates of solvolysis of... 

Higher alcohols have more than three carbon atoms. Examples are the dihydric alcohol, ethylene glycol used for antifreeze, brake fluids and as derivatives in resins, paints " " osives, and polyester fibers. Reactions with propylene make propylene glycol, a moistening ag foods and tobacco. 

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