Divinyl benzene styrene/divinylbenzene copolymer

Tatsuzawa et aq 36,37,45,59 separat.ed cold drugs and neuroleptics by using a styrene-divinyl benzene-methyl methacrylate copolymer as stationary phase. The best results were obtained with methanol - ammonia (99 1) as mobile phase. The effect of the pH and of the composition of the mobile phase on the separation were discussed. Aramaki et al.70 analyzed a series of alkaloids on a macroporous styrene-divinylbenzene copolymer with alkaline acetonitrile - water mixtures as mobile phase (Fig. 7.10). The columns showed excellent stability, and also under the strong basic conditions used for the analysis of the alkaloids. 

Styrene, divinyl-benzene (DVB), dioxane, methanol and cyclohexane were purified according to published methods [ 12] Styrene-divinylbenzene copolymer (X AD-8) was procured from Fluka... 

J. W. Kelly and J. T. Stewart, Separation of selected beta lactam antibiotic epimers on gamma cyclodextim ion exchange ethylvinyl benzene divinylbenzene copolymer and poly(styrene-divinyl benzene) copolymer stationary phases, J. Liquid Chromatogr., 14 2235(1991). 

Similar to the case of styrene, the copolymers of alkylstyrenes and arylstyrenes are common. The copolymerization is done for the same purposes as for polystyrene, namely to improve/modify certain properties. Copolymerization with divinylbenzene is probably the most frequently utilized. This copolymerization improves mechanical resistance, decreases solubility, and improves thermal resistance. For example, thermal decomposition of poly(vinyltoluene-co-divinyl benzene) 10-50% DVB starts at a higher temperature than that of poly(vinyl toluene). The decomposition at 560° C generates C1-C4 hydrocarbons, benzene, toluene, ethylbenzene, styrene, ethyltoluene, a-methylstyrene, vinyltoluene, divinylbenzene, naphthalene, and ethylstyrene, with a distribution that varies with copolymer composition [71, 118]. 

Both anion and cation hydrocarbon-type exchange membranes (styrene-divinyl-benzene copolymer type) are generally stable in ordinary concentrations of acid solutions (about 40% sulfuric acid, 10% hydrochloric acid, 20% nitric acid, 50% acetic acid) and in alkali solutions such as sodium hydroxide (5%), ammonia (4%), etc.64 However, ion exchange membranes using ethylene glycol dimethacrylate, sulfoethyl methacrylate, and other acrylic and methacrylic esters, are less stable than styrene-divinylbenzene type membranes. 

Figure 10 illustrates the result of a swelling of crosslinked polymer particles. In this case 2 ym particles of styrene-divinyl benzene copolymer (5 % divinylbenzene) were first swollen with dioctyl adipate (20 % by volume) and then in the second step with chlorobenzene (125 times the volume of the polymer). It is seen that the cores all seem to lie at the side of the droplets. However, this position is an artefact in the way that it apparently is caused by rotational movements of the droplets under the microscope. 

A divinylbenzene-ethylene-styrene copolymer is sulfonated by 3.5-10% solutions of chlorosulfonic acid in organic solvents, e.g. chloroform or 1,2-dichloroethane at RT to yield cation-exchange resins. Porous st)rrene-divinyl-benzene-ethylvinylbenzene copolymers have also been treated with the reagent and hydrazine hydrate to form ion-exchange resins containing sulfonyl hydrazide groups. ... 

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