Glycol borates

Processes to produce boric acid esters are based on the azeotropic removal of water from a mixture of the appropriate alcohol, phenol, or glycol, and boric acid. A suitable hydrocarbon azeotroping agent is used to help remove the water. The water is removed continuously by using a condenser that allows continuous return of the solvent to the reaction vessel. Eor some borate esters, such as the glycol borates, distillation can result in decomposition. 

In general (19) hydrophobic modifications and methylation decrease Rf, hydrophilic, e.g., succinylations increase Rf, low vs. high negative charges—dependent on TLC and solvent system c/r>glycols— borate retards and periodate oxidizes (sensitive). 

Choi N-S, Lee YM, Cho KY, Ko D-H, Park J-K (2004) Protective layer with oligo(ethylene glycol) borate anion receptor for lithium metal electrode stabilization. Electrochem Common 6 1238-1242. doi 10.1016/j.elecom.2004.09.023... 

U.S. Borax Research Corp., Anaheim, California, markets several borate esters under the trademark BORESTER. These include triethanolamine borate (BORESTER 20), tricresyl borate (m- and p-isomers) (BORESTER 8), and the biborate (4) (BORESTER 7). Whereas the chemical name for (4) is given in Table 1, it is commonly referred to as trihexylene glycol biborate [26545-48-2] and is prepared by the reaction of two moles of boric acid and three moles of hexylene glycol. 

Fig. 3. Oxygen Index Test of Polylite 33-442 Containing Dibromoneopentyl Glycol, ZB - Zinc Borate, Sb - Antimony Oxide. (Reproduced with permission from Ref. 2. Copyright Plastics Compounding 1985).

Japanese workers have described a stable aqueous solution of neomycin with the incorporation of a borate buffer (pH 6) and E.D.T.A.295 The presence of 1-10% of glycerol, propylene glycol or mannitol has been claimed to improve the solution appearance by preventing discoloration29°. The presence of polyols also prevented a decrease in pH value of the solution. Discoloration may also be prevented by addition of 0.1% sodium metabisulphite at a solution pH of 6.6 to 6.8297. 

In the polarography of aqueous formaldehyde solutions the only reducible species is the unhydrated aldehyde, and under suitable conditions the observed current is dependent on the rate of dissociation of methylene glycol. This was first shown by Vesely and Brdidka (1947) and by Bieber and Triimpler (1947a) later work (BrdiiSka, 1955) demonstrated catalysis by borate and hydroxide ions, but no extensive study has been made by this method. An exact mathematical solution of the diffusion problem is difficult to obtain a recent review has been given by Brdi5ka (1960). 

This is analogous to the preferred formation of borate complexes from syn-1,2- and, yyn-l,3-diols rather from their ctntt-isomers (and terminal glycols). The latter observation has... 

Dissolve the Sodium Citrate and sodium borate in approximately 20 ml water. Apply heat if necessary to dissolve. Combine the surfactants, propylene glycol and ethyl alcohol. Add the Sodium Citrate and sodium borate solution to the surfactants mixture. Add the sodium xylene sulfonate. Adjust the pH to 9.5 using TEA or dilute sodium hydroxide. Bring the volume of the mixture to 100 ml using water. 

At pH 10, the 5,6-glycol group of D-glucofuranosides appears to have little importance in formation of borate complexes A. B. Foster and M. Stacey, J. Chem. Soc., 1778 (1955). 

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