Diethylene glycol formal

The copolymerization between trioxane and suitable comonomers (ethylene oxide, 1,3-dioxolane, diethylene glycol formal, 1,4-butane diol formal in amounts of 2-5% by weight) is performed using cationic initiators. The cationic initiators could be Lewis acids, such as BF3 or its etherate BF3Bu20 which was used, for example by Celanese (the mechanism of this reaction was studied in detail [163,164]) or protic acids such as perchloric acid, perfluoroalkane sulfonic acids and their esters and anhydrides. Heteropoly acids were used and also a series of carbenium, oxocarbenium salts, onium compounds, and metal chelates. To regulate the molecular weight chain-transfer agents, such as methylal and butylal, are added. 

Accortliiig to Seymour the plithalate ester of diethylene glycol formal is useful as a plasticizer for cellulose derivati es. This formal is prepared by condensing two niols of diethylene glycol with one mol of paraformalde-hj de in the presence of sulfuric acid. 

Stoddart and his coworkers have reported syntheses of the trans-syn-trans and the trans-anti-trans isomers of dicyclohexano-18-crown-6 The synthesis of these two compounds from trans-l,2-cyclohexanediol was accomplished in two stages. First, the diols were temporarily linked on one side by formation of the formal, and this was treated with diethylene glycol ditosylate and sodium hydride to form the hemi-crown formal. Removal of the formal protecting group, followed by a second cychzation completed the synthesis. The synthesis of the trans-anti-trans compound is illustrated below m Eq (3 12) and the structures of the five possible stereoisomers are shown as structures 1—5. 

A Division of Pharmacology had been formally set up in the Food and Drug Administration in 1935, composed mostly—as one of its members, Edwin P. Laug, remembered—of "biochemists who then changed sails and became pharmacologists" (7] ). To study the toxicity of lead and arsenic pesticide residues formed the division s initial purpose, but the Elixir Sulfanilamide crisis brought an almost total shift of effort to diethylene glycol. 

Mixing of the crystalline ingredients of oxidant, fuel elastomer binder (butadiene-2-methyl-5 vinyl-pyridine copolymer plasticized with the formal of diethylene glycol monobutyl ether) 26% by vol is done in a sigma blade mixer. The completed mix is blocked in a hydraulic press to form a chge suitable for extrusion. The extruded strand is cut into grain blanks which are cured at... 

The cyclic formal of diethylene glycol, i.e. 1,3,6-trioxocane, shows a very interesting temperature-dependent nmr spectrum, especially at 251 MHz. > ) The C-2 proton band changes from a single line at room temper-... 

Butyl Carbitol acetate n-Butyl Carbitol acetate Butyl Carbitol Acetate. See Diethylene glycol butyl ether acetate Butylcarbitol formal... 

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