1,4-Butanediol analysis

Specifications and Analytical Methods. Butanediol is specified as 99.5% minimum pure, determined by gas chromatography (gc), sohdifying at 19.6°C minimum. Moisture is 0.04% maximum, determined by Kad-Fischer analysis (dkecdy or of a toluene a2eotrope). The color is APHA 5 maximum, and the Hardy color (polyester test) is APHA 200 maximum. The carbonyl number is 0.5 mg KOH/g maximum the acetal content can also be measured dkecdy by gc. 

Figure 15.11 (a) Total ion clnomatogram of a Grob test mixture obtained on an Rtx-1701 column, and (b) re-injection of the entire clnomatogram on to an Rtx-5 column. Peak identification is as follows a, 2,3-butanediol b, decane c, undecane d, 1-octanol e, nonanal f, 2,6-dimethylphenol g, 2-ethylhexanoic acid h, 2,6-dimethylaniline i, decanoic acid methyl ester ], dicyclohexylamine k, undecanoic acid, methyl ester 1, dodecanoic acid, methyl ester. Adapted from Journal of High Resolution Chromatography, 21, M. J. Tomlinson and C. L. Wilkins, Evaluation of a semi-automated multidimensional gas chromatography-infrared-mass specti ometry system for initant analysis , pp. 347-354, 1998, with permission from Wiley-VCH. 

An optically pure polyester has been synthesized by PPL-catalyzed enantioselective polymerization of bis(2,2,2-trichloroethyl) frans-3,4-epoxyadipate with 1,4-butanediol in anhydrous diethyl ether (Fig. 4) [47]. The molar ratio of the diester to the diol was adjusted to 2 1 so as to produce the (-) polymer with enantiomeric purity of > 96 %. From end group analysis, the molecular weight was calculated to be 5.3 x 103. 

Synthesis of 2,3-butanediol enantiomers syn-hydroxylation of trans-2-butene. Retrosvnthetic Analysis... 

Compared to 1,4-butanediol, which forms tetrahydrofuran byproduct in PBT polymerization, PDO is difficult to cyclize into oxetane because of the high ring strain. Oxetane was not found in the byproduct analysis [23],... 

The FD mass spectra provide qualitative distribution of various species in HTE polymers. Most importantly, the spectra also provide the structural information to prove the incorporation of one unit of modifier, ethylene glycol or water, in HTE polymers. This is also the first analysis that distinguishes HTE polymers synthesized in conjunction with ethylene glycol and water. The incorporation of one unit of modifier into the polymer chain has been estimated semi-quantitatively with H NMR method for the copolymerization of tetrahydrofuran and propylene oxide in conjunction with 1,4-butanediol as a modifier (7). 

Figure 4. Differential thermal analysis results (1) benzene-water-HCl on Z200H, (2) butanediol-water on Z500, (3) butanediol-water on Z200H...

Acrylic Crosslinkers. Butanediol diacrylate (IV) (BDDA) is a popular crosslinker used in the preparation of many polymers used for inks, paints, and plastics. Low-levels of impurities can adversely affect product properties. As previously discussed, K+IDS provides a powerful qualitative technique, but yields poor quantitative data when analyzing volatile chemicals. BDDA is amenable to analysis by GC, unfortunately any higher-molecular-weight adducts exceed the volatility range amenable to GC. Moreover, BDDA is not chromophoric thereby HPLC characterization is also difficult. 

Butanediol is specified as 99.5% minimum pure, determined by gas chromatography, solidifying at 19.6°C minimum. Moisture is 0.04% maximum, determined by Karl Fischer analysis (directly or by a toluene azeotrope). 

The GC separation of esters and the selection of the stationary phase represent problems of varying degrees of complexity in individual cases. An acceptable separation can usually be obtained on different polyester stationary phases (EGA, butanediol succinate polyester, EGS, etc.), Carbowax-type phases, OV-17, OV-225 and SE-30. Non-selective and non-specific stationary phases are preferred. The supports should not be acidic, and they are sometimes modified by silanization. In particular instances, when other groups are also derivatized prior to the analysis the selection of the stationary phase may be very difficult. These problems are discussed for individual types of compounds in Chapter 5. 

Enantiomers of carboxylic acids may sometimes be separated by GC as methyl esters, but special derivatives are mostly prepared for this purpose. Ackman et al. [188] resolved enantiomers of isoprenoid fatty acids after their conversion into L-menthyl esters. The acids under analysis were chlorinated by refluxing with distilled freshly prepared thionyl chloride and the chlorides produced were treated with L-menthol in the presence of pyridine under strictly anhydrous conditions. GC separation was carried out in a capillary column coated with butanediol succinate polyester. Annett and Stumpf [189] made use of L-menthyloxycarbonyl derivatives for the separation of enantiomers of methyl esters of hydroxy acids. The derivatization reagent, L-menthyl chloroformate, was prepared by the reaction of L-menthol with phosgene, with cooling with ice. Diastereoisomers of different hydroxy acids were thus separated on 1.5% OV-210. 

Jones AW, Nilsson L, Gladh SA, Karlsson K, Beck-Friis J. 2,3-Butanediol in plasma from an alcoholic mistakenly identified as ethylene glycol by gas-chromatographic analysis. Clin Chem 1991 1453-5. 

Finally, the stereospecificity of the phosphorane-promoted cyclodehydration is adequately demonstrated in the reaction of d,Z-2,3-butanediol (9) with DTPP in CD2CI2 (35 C, 10 h). The stepwise nature of the cyclodehydration process gives exclusively d5-2,3-epoxybutane (10 >99%) by NMR analysis [6 12.9 (CH3) and 52.4 (CHO)] (76). This latter result is consonant with the previous findings of Denney etal. 24) where a mixture containing 88% d,/- and 12% zne5o-4,5-dimethyl-2,2,2-triethoxy-1,3,2X5-dioxaphospholanes (11) gave a mixture of 85% cis- and 15% /rans-2,3-butene oxides (10), respectively, during tiiermolysis (117°C, 42 h) (equations 2 and 3). Polymeric Dioxaphospholanes. 

Unless otherwise noted, the reaction was carried out using 1.0 mmol of Michael acceptors and donors (1 1) in 1.0 mL of solvent. The molar ratio of acceptor donor ruthenium is 50 50 1 (S/C = 50). Isolated yield after flash chromatography on the silica gel. Determined by HPLC analysis. dS/C = 100. eNot determined. -Determined by 13C NMR of the ketals derived from the products and (2R,3 )-butanediol. 

All packings were commercial products 1, 1,4-butanediol succinate polyester 2, diethylene glycol succinate polyester 3, diethylene glycol succinate polyester that had heen used extensively for analysis of fatty acid esters. 

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