Polymerization Of Divinylbenzene Research Articles

Soybean Metal-Binding Proteins: Calmodulin Purification by Hydrophobic Interaction with Polymer 3520

Polymer 3520, a non-polar styrene divinylbenzene polymer, provides a simple way to purify calmodulin (CAM) from soybeans. This polymer, which selectively adsorbs CAM by hydrophobic interaction within the polymer matrix, contains no exchangeable groups; thus, interaction with CAM requires no Ca++ ions, and elution is achieved with 50% ethanol. Purification by this form of reversed-phase liquid chromatography is a substantial improvement over the conventional method, which requires high salt in elution buffers. CAM in soybean meal is first extracted with 80% ethanol in the presence of EGTA at room temperature and then chromatographed directly on a polymer 3520 column to yield pure CAM. Addition of non-ionic detergent (Nonidet P-40) to the ethanolic extract helps to separate extraneous proteins, lipids, sugars, and isoflavones. Such isolated CAM migrates as a single band during polyacrylamide gel electrophoresis and reversed-phase HPLC, and it retains activity stimulatory to phosphodiesterase.

The crystallization of calcium carbonate on polymeric substrates

Sulfonated polystyrene and polystyrene divinylbenzene polymers were found to be substrates, suitable for the growth of calcium carbonate monohydrate, slowly converting into the thermodynamically stable calcite. The nature of the calcium carbonate polymorph forming was confirmed as being calcium carbonate monohydrate. Kinetics analysis has shown that the apparent order of the crystal growth reaction is 2.0, pointing out a surface controlled mechanism. Analysis of the initial rates of reaction as a function of the solution supersaturation, according to the classical nucleation theory, yielded a value of 29 mJ/cm2 for the surface energy of the growing phase and a size of 4 ions in the ion cluster forming the critical nucleus. In all cases, a well-defined induction period preceded the onset of calcium carbonate monohydrate overgrowth, reflecting the time required for the formation of the critical nucleus. The induction times were inversely proportional with respect to the solution supersaturation while the rates of the concomitant crystal growth increased with supersaturation.

Fischer-Tropsch synthesis catalyzed by iron catalyst supported on porous polymers: I. Synthesis of the supported catalyst and study of the repartition of the catalyst in the polymeric support

Macroporous styrene-divinylbenzene and 4-vinylpyridine divinylbenzene polymers were used as supports for an iron Fischer-Tropsch catalyst. The catalyst was based on iron in the zero-valent state. Two methods of preparation were tested: reduction of the catalyst after or before introduction into the polymeric support. In both cases, the dispersion of the catalytic species in the polymeric support was determined by electron probe X-ray microanalysis. It was shown that reduction of the catalyst after diffusion into the polymeric support gives a homogeneous distribution of the catalyst in the beads, whereas the diffusion of already reduced catalyst into the support leads to a heterogeneous mixture of species.

Application of packed column supercritical fluid chromatography to the analysis of barbiturates

The analysis of barbiturates using packed column supercritical fluid chromatography (SFC) has been investigated. The separations were carried out on either an ODS bonded silica or polystyrene—divinylbenzene polymer column with carbon dioxide as the mobile phase and flame ionisation detection. All the barbiturates were strongly adsorbed on the ODS-silica column, but reasonable separations were obtained by using the polymer column.

Effect solvatant des copolymères styrène–macromère a chaîne polyoxyéthylène. Influence du support polymère

AbstractPolyoxyethylene macromers were used to prepare functionalized linear and crosslinked copolymers with styrene and divinylbenzene. Gel or macroporous resins were prepared. These copolymers and resins were used as anionic activators for the Williamson reaction of potassium phenoxide and alkyl bromides under solid–liquid or solid–liquid–liquid (triphase) conditions. In contrast to similar resins obtained from chemical grafting of polyoxyethylene onto chloromethylated styrene–divinylbenzene polymers, the activity factors were strongly dependent on the composition of the resins and their morphology: an optimum activity was obtained for a 0.05M fraction of macromers in soluble copolymers and crosslinked resins. In addition, a macroporous resin with large pores was more efficient than a gel‐type resin of similar composition. These effects are discussed in terms of accessibility of the activating group and compatibility of the support with the medium.

Formation of non-graphitizable isotropic spherulitic carbon from poly-divinylbenzene by pressure pyrolysis

Isotropic spherulites of carbon stable at 2000° C were synthesized by the pressure pyrolysis of divinylbenzene polymer sealed in a capsule. The morphology of the synthesized carbon was pressure and temperature dependent being influenced by the state of polymerization of the starting polymer. Using a polymer prepared at atmospheric pressure and 150° C without catalyst, isolated spherulitic carbon was formed at 700° C and pressures of 1000 to 1250 kg cm−2. These spherulitic carbons were optically isotropic, hard and non-graphitizable after heat treatment at 2000° C. Such carbons originate in the co-existence of higher and lower molecular weight products of pressure pyrolysis and the survival cross-linkages in the original polymer.

Preparation of homogeneous "living" polyvinyl gels with application to solvent purification

Abstract : A method is presented for maintaining a high level of purity in organic solvents to be used in anionic polymerizations. The development of this technique has entailed synthesis of structurally unique polyvinyl gels which are labile to anionic initiation. Preparation of macroscopic homogeneous gels from divinylbenzene (DVB) and ethylstyrene (ES) is shown to result in the immobilization of a significant amount of residual vinyl groups. Conditions necessary for eliminating unwanted syneresis during the gelation include initiation of the reaction with butyllithium and polymerization in a nonpolar solvent (e.g. benzene) to which an appropriate amount of tetrahydrofuran (THF) has been added. The success of this method in obtaining the desired product is attributed to the influence of the THF on the polymerization of DVB; a mechanism is proposed and experimentally supported which accounts for the observed results. (Author)

Contribution de la chromatographie en phase liquide à haute performance à la séparation des lanthanides trivalents sur résine cationique en présence d'edta : I. Synthèse et propriétés générales des résines pelliculaires polystyrène-divinylbenzǹe sulfonates

High-performance liquid chromatographic separation of trivalent lanthanides on cationic exchanger with EDTA. I. Synthesis and general properties of polystyrene-divinylbenzene sulphonate pellicular ion exchangers The synthesis of pellicular ion exchangers by incomplete sulphonation of a styrene—divinylbenzene polymer following the method described by Hansen and Gilbert is controlled by scanning electron microscopy. The thickness of the ion-exchange shell is obtained by measuring the exchange capacity and the swelling due to the sulphonation. The exchange properties of homogeneous and thick-shell ion exchangers are similar if referred to the weight of exchanger. On the contrary, for thin shells, the behaviour seems to be that of a homogeneous ion exchanger of higher crosslinking.

Styrene divinylbenzene-based strong acid ferromagnetic cation exchanger

A strong acid ferromagnetic cation-exchange resin based on styrene divinylbenzene polymer has been prepared and characterized.

The Change of Pore Structure of Various Hard Carbons by Heat Treatment

The BET surface area and pore size distribution were determined by physical adsorption-desorption measurement of carbon dioxide at 195K on various hard carbons, prepared from divinyl benzene polymer (DVBP), copolymer of divinyl benzene and acrylic acid (IRC-50), phenol-formal-dehyde resin (P-F) and carbon fiber (C-F), and change of pore structure in carbons with heat treatment temperature (HTT) was discussed.Each carbon was heat treated at various temperatures between 1173-2273K (900-2000°C)Below the heat treatment temperature of 1473K, the isotherms for all carbons were those of Langmuir-type.Above 1673K, however, the isotherms were BET-II-type, except the carbon fiber. The surface area of IRC-50 and C-F carbons decreased from relatively large value (ca.300m2/g) below 1473K to small value, less than 100m2/g, above 1673K.On the DVBP carbon, however, rather large area, few hundreds square meters per gram, was maintained over the temperature range examined. The area of P-F carbon was 31.5m2/g at 1273K, increased to 59.7 at 1773K and then decreased to 27.5m2/g at 2273K.The pores in these carbons were micro pores and transitional pores.In the carbons with HTT of 1473K, almost all of pores had the diameter less than about 30 A.With the increase in HTT, the maximum of the pore diameter shifted to larger side.The temperature programmed desorption (TPD) method was proved to be a promising way to show an outline of the pore size distribution in carbons.

Synthesis of the sequence of oxytocin on a hydroxymethylstyrene‐divinylbenzene polymer

AbstractThe preparation of a hydroxymethylstyrene‐2%‐divinylbenzene polymer is described.The optimal method for the esterification of this polymer with N‐t‐butoxy‐carbonyl amino acids was found by using N,N′‐carbonyldiimidazole, the remaining hydroxyl groups being protected by formation of their acetates.On this polymer the nonapeptide sequence of the hormone oxytocin was synthesized and then split off in two ways. Tertiary base‐catalysed methanolysis (found in this Laboratory) gave the nonapeptide methyl ester: Z‐Cys(BZL)‐Tyr‐Ile‐Gln‐Asn‐Cys(BZL)‐Pro‐Leu‐Gly‐OMe a. L‐Amino acids are meant. b. Abbreviations used here and later: IUPAC, Information Bulletin 25, February 1966, 32‐40; 26, August 1966, 11‐19; 27, December 1966, 16‐18; 30, October 1967, 27‐32. , and ammoniacal methanol gave the carboxy‐terminal amide: Cys(BZL)‐Tyr‐Ile‐Gln‐Asn‐Cys(BZL)‐Pro‐Leu‐Gly‐NH2(H2O · HBr).The usual debenzylation and cyclization of the amide gave biologically active material.

Gas Chromatographic Determination of Ethanol in Pharmaceuticals: Comparison of Polyethylene Glycol 400 and Divinylbenzene Polymer Columns

Gas chromatography with a flame ionization detector was used with an official NF XII and a divinylbenzene polymer (DVBP) column to determine ethanol in pharmaceuticals. The DVBP column separated ethanol from methanol and gave results comparable to the polyethylene glycol 400 (PEG 400) column for various types of pharmaceuticals. Gas chromatography with a flame ionization detector was used with an official NF XII and a divinylbenzene polymer (DVBP) column to determine ethanol in pharmaceuticals. The DVBP column separated ethanol from methanol and gave results comparable to the polyethylene glycol 400 (PEG 400) column for various types of pharmaceuticals.

A kinetic study of catalytic graphitization of hard carbon

The course of catalytic graphitization of hard carbon was studied kinetically. Carbons produced at 800°C from divinyl benzene polymer, Amberlite IRC-50 and furfural-furan resins with added cupric oxide were heat treated at temperatures between 1450 and 1525°C for 30–180 min. Graphitization proceeded abruptly up to a certain degree ( d = 3.36~.37 A ̊ ) and the amount of highly graphitized material gradually increased according to the first order rate equation. Amberlite IRC-50 carbon was most easily graphitized, while divinyl benzene and furfural-furan carbons correspondingly increased in their resistance to graphitization. The energy of activation of the processes for Amberlite IRC-50 and divinyl benzene polymer was approximately 100 kcal per mole and that for furfural-furan resin somewhat higher. It was assumed that copper cleaved the cross-linking carbon-carbon bonds to accelerate graphitization.

Low temperature catalytic graphitization of hard carbon

Artificial resins producing non-graphitizing carbons such as divinyl benzene polymer and condensates of furfuryl alcohol or furfural, were heat treated at temperatures between 1400 and 2300°C with an addition of various kinds of metallic compounds. Using X-ray diffraction it was found that carbons thus obtained were highly graphitized. The catalytic graphitization starts at temperatures between 1400 and 1500°C and is accompanied by an appearance and disappearance of several unidentified diffraction peaks, which may originate from some kind of intermediate complexes of carbon and metals.