Gas Chromatographic Detection of Impurities in Commercial Divinylbenzene R a y E. Hannah, M a r y L. Cook, and Joseph A. Blanchette Foster Grunt Co., Inc., Leominster, Muss. ~~~
GASCHROMATOGRAPHIC ANALYSES of 55-60 divinylbenzene solutions have been reported by several workers (1-3) using thermal conductivity detectors with only a limited number of components detected. We have analyzed this material with a flame ionization detector and have found several impurities not previously reported. Divinylbenzene (DVB) is produced by dehydrogenation of diethylbenzene. Commercial material usually contains about 55-60x meta and para DVB with the remainder being a number of saturated and unsaturated aromatics in varying amounts. Accurate analysis of the material by wet techniques is difficult and time consuming ( 4 ) . Wolf and coworkers (1) analyzed DVB by gas-liquid chromatography using dinonyl phthalate as the liquid phase. They reported that 12 compounds were detected and nine identified in the finished (55-6Ox) sample they analyzed. Blasius and Beushausen ( 2 ) reported the analysis of DVB using several different phases. Tricresyl phosphate was reported to give the best separation between diethylbenzene (DEB), ethylvinylbenzene (EVB) and DVB while Apiezon L and High Vacuum oil R gave better resolution of the isomers of DEB and DVB. No relative retention times o r resolution data were given. Recently, Wiley and Dyer (3) reported the analysis of two commercial samples of DVB using polypropylene glycol. Relative retention values for 10 known compounds were given. Since the polymerization characteristics of DVB are affected not only by the ratio of meta and para isomers of DVB (5,6) but also by some of the impurities, it was of interest to develop techniques for analyzing trace components. The flame ionization detector was chosen for this work because it was reported to be more sensitive than the thermal conductivity detector.
EXPERIMENTAL Apparatus. Perkin Elmer chromatographs, model 154 with thermal conductivity detector and model 811 with flame ionization detector, were used in this work. Sample injections were made with 10-pl Hamilton syringes. The column descriptions and operating conditions are given in the text and Table I. Procedure. The optimum conditions for separating the DVB components were determined by injecting a standard sample at different column temperatures, carrier gas flow rates, and liquid phase concentrations. This procedure was repeated for each liquid phase studied and the optimum con-
(1) F. Wolf et al., Abkandl. Deut. Akad. Wiss. Berlin, KI. Chem. Geol. Biol., No. 1, 513-23 (1962) C.A., 59, 6571h. (2) E. Blasius and J. Beushausen. 2. Anal. Cliem. 197, 228-36 (1963). (3) R. H. Wiley and R. M. Dyer. J. Polymer Sci., Part A , No. 2, 3153-8 (1964). (4) E. N. Luce. in “High Polymers,” Vol. XI1 “Analytical Chemistry of Polymers,” Part 1;p. 430, G. M. Kline, editor, Interscience, New York, 1959. ( 5 ) R. H. Wiley and G. Devenuto, J . Polymer Sci., Part A. Vol. 2, 5347-53 (1964). (6) R. H. Wiley and G. Devenuto, Zbid., Vol. 3, 1959-67 (1965). ’
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ANALYTICAL CHEMISTRY
Table I. Isomer Resolution Data
Liquid phase Apiezon L, 15 % on Chromsorb
Resolution of Meta and Para Isomers EthylDiethylvinylDivinylbenzene benzene benzene
Wa 1 .oo 0.89 1.16 DC 200 Silicone Oil, 20% on 0.52 0.0 0.74 Gas Pack Fb Di-2-ethylhexyl Sebacate, 20 on Chromsorb W“ 0.98 0.81 1.48 Polyethyleneglycol (Carbowax 1500), 20% on G C 2 2 ~
