Styrene-divinyl benzene

Pendent vinyl groups in styrene-DVB copolymers have been analysed by infrared and Raman spectroscopy [72-83] and by wet chemical methods [71, 82, 84] after extents of reaction varying from before gelation to after nearly complete conversion of monomers. Ford and co-workers [85] report a new analytical approach to the problem. Copolymers of styrene with methane- C-labelled p-DVB were analysed by liquid state and solid state cross-polarisation magic angle spinning (CP-MAS) C-NMR methods. 

The residual vinyl groups of all labelled samples were analysed quantitatively from peak areas in the NMR spectra by two methods. First, the area of the 137 ppm vinyl peak was compared with the area of all of the aromatic carbon signals in the spectrum due to styrene and DVB carbons in natural abundance. Second, the area of the 137 ppm peak was compared with the area of all of the aliphatic carbon signals in the spectrum, which includes signals from both polymerised labelled carbons of the DVB and from all other aliphatic carbons at natural abundance. It was assumed that all carbon atoms in the sample are equally detectable in each NMR spectrum. Results are shown in Table 12.6. All of the labelled polystyrene networks were also analysed by the bromination of residual vinyl groups. 

The i C-NMR and bromination methods were applied to several commercial crosslinked polystyrenes prepared with unlabelled DVB, which usually consists of a 2 1 meta/para 

Ford and co-workers [85] concluded that all common styrene-DVB copolymers, containing even as little as 1% DVB, contained unreacted DVB vinyl groups. No method is available yet for accurate, quantitative analysis of residual vinyl groups. Wet chemical methods do not detect vinyl groups in the most hindered parts of the highly crosslinked, heterogenous networks. Infrared and C-NMR analyses may contain systematic errors in peak area determinations. 

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Novolacs are often modified through alkylations based on reactions with monomers other than, and in addition to, aldehydes during their manufacture. Examples might be inclusion of styrene, divinyl benzene, dicyclopentadiene, drying oils, or various alcohols. Despite significant production of all of these variants, most novolac volume is produced using phenol and formaldehyde. 

Table 9.7 summarizes the comparison of SEC column performance with regard to particle size of the packing material. The author tried to create this table using the test results of different manufacturers of styrene-divinyl-benzene columns. 

P-p-C H4Ph2CCl, Pyr, 25°, 5 days, 90%, where P = styrene-divinyl-benzene polymer. Triarylmethyl ethers of primary hydroxyl groups in glucopyranosides have been prepared using a polymeric form of triphenylmethyl chloride. Although the yields are not Improved, the workup is simplified. 

Polymetric matrix Polydiallyldimethylammonium bromide [9] Polypyrrole [10[ Poly (MA -dimethyb-S -pyrrolidinium bromide [11J Styrene-divinyl benzene copolymers [4] Polyacrylamide [12]... 

The Separation of Some Phthalate Esters by Exclusion Chromatography on Styrene-Divinyl Benzene Based Gel... 

Poly(styrene-divinyl benzene) H Reversed phase, gel permeation... 

Figure 4 Crossover of peak retention times as a function of gradient rate in the separation of peptides. (Previously unpublished data are drawn from Swadesh, J. K., Tryptic fingerprinting on a poly(styrene-divinyl benzene) reversed phase column, /. Chromatogr., 512, 3215, 1990.92)...

Swadesh, J. K., Tryptic fingerprinting on a poly(styrene-divinyl benzene) re-versed-phase column,. Chromatogr., 512, 315, 1990. 

Superheated water at 100°-240 °C, with its obvious benefits of low cost and low toxicity, was proposed as a solvent for reversed-phase chromatography.59 Hydrophobic compounds such as parabens, sulfonamides, and barbiturates were separated rapidly on poly(styrene-divinyl benzene) and graphitic phases. Elution of simple aromatic compounds with acetonitrile-water heated at 30°-130 °C was studied on coupled colums of zirconia coated with polybutadiene and carbon.60 The retention order on the polybutadiene phase is essentially uncorrelated to that on the carbon phase, so adjusting the temperature of one of the columns allows the resolution of critical pairs of... 

Figure 10 Separation of monochloroacetate, dichloroacetate, and trichloroacetate on a sulfonated poly(styrene-divinyl benzene) column with suppressed conductivity detection. Column 2% cross-linked sulfonated poly(styrene-divinyl benzene) capacity 0.02 meq/g. Flow rate 64 ml/hr. Eluant 15 mM sodium phenate. Suppressor 0.28 x 25 cm Dowex 50W X8 column (200-400 mesh). Detector Chromatronix conductivity cell connected to a Dow conductivity meter. (Reprinted with permission from Small, H., Stevens, T. S., and Bauman, W. C., Anal. Chem., 47,1801,1975. 1975 Analytical Chemistry.)...

HPLC of aqueous simulants or water using an ion exclusion column (styrene divinyl benzene polymer with sulfonated [cationic] ion-exchange groups). Derivitisation with fluorescamine, 4-phenylspiro-[furan 2-(3),... 

The reaction is reversible and therefore the products should be removed from the reaction zone to improve conversion. The process was catalyzed by a commercially available poly(styrene-divinyl benzene) support, which played the dual role of catalyst and selective sorbent. The affinity of this resin was the highest for water, followed by ethanol, acetic acid, and finally ethyl acetate. The mathematical analysis was based on an equilibrium dispersive model where mass transfer resistances were neglected. Although many experiments were performed at different fed compositions, we will focus here on the one exhibiting the most complex behavior see Fig. 5. 

TLC separation of the components of black dye commercial product (BDCP) was performed on silica layers. The chemical structures of the dye components are shown in Fig. 3.17. Dyes were extracted from the effluent of the dye processing plant, from the untreated river water and from the drinking water treatment plant. The organic extracts were further concentrated and purified using a copolymer of styrene divinyl benzene. The mobile phase for TLC separation consisted of toluene-ethyl acetate (8 1, v/v). The Rp values of dye components were 0.43 (C. I. Disperse Violet 93), 0.48 (C. I. Disperse Orange 37) and 0.59 (C. I. Disperse Blue 373), respectively. 

Aromatic electrophilic substitution is used commercially to produce styrene polymers with ion-exchange properties by the incorporation of sulfonic acid or quaternary ammonium groups [Brydson, 1999 Lucas et al., 1980 Miller et al., 1963]. Crosslinked styrene-divinyl-benzene copolymers are used as the starting polymer to obtain insoluble final products, usually in the form of beads and also membranes. The use of polystyrene itself would yield soluble ion-exchange products. An anion-exchange product is obtained by chloromethylation followed by reaction with a tertiary amine (Eq. 9-38) while sulfonation yields a cation-exchange product (Eq. 9-39) ... 

Williams [105] investigated the effect on stability of water-in-styrene/divinyl-benzene HIPEs, stabilised with nonionic surfactants, on addition of a range of cosurfactants. Generally, stability was reduced, with higher degrees of coalescence being observed with cosurfactant addition. The stability appeared to be inversely related to the HLB number of the cosurfactant. 

Apparent values calculated on the basis of the extrapolated polystyrene calibration curve for 106A pore-size 20/i particle poly(styrene-divinyl-benzene) column. 

The sorbents, Chromosorb 102 and XAD-2, which are styrene-divinyl benzene cross-linked porous polymers, proved to be most useful in our studies. Capacity of the sorbent sampling tubes was not a problem with the pesticides we studied since most were not extremely volatile. Sampling humid atmospheres of the pesticides also did not affect the sorbent capacity since these porous polymers are hydrophobic. 

PCB ADSORPTION. PCBs are practically insoluble in water because of a very weak solute-water interaction PCBs will have a strong solute-polymer interaction if a polymer such as styrene-divinyl-benzene is used water will have a weak interaction with styrene-divinylbenzene thus, conditions for effective adsorption are present. Therefore, large volumes of water can be passed through a column packed with a styrene-divinylbenzene polymer, and the PCBs will be adsorbed (partitioned) efficiently. 

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