Macroreticular Cation-exchange Resin Research Articles

Reaction Equilibrium for the Liquid-Phase Simultaneous Decomposition of Methyl tert-Butyl Ether and tert-Butyl Alcohol over Ion-Exchange Resin

Using a macroreticular cation exchange resin (Amberlyst 35) as catalyst, reaction equilibrium for the simultaneous splitting of methyl tert-butyl ether and tert-butyl alcohol were conducted in the temperature range of 50–110 °C at 2.0 MPa. When the initial charged methyl tert-butyl ether to tert-butyl alcohol molar ratios were varied and no other reagents were used, the composition effect on activity coefficient calculation was evaluated. As compared with theoretical thermodynamic values, the modified UNIFAC method with proper model parameters is better than the UNIFAC and UNIQUAC methods for calculating the activity-based equilibrium constants of the quinary reaction system. Introducing the best model, the modified UNIFAC method, the determined standard enthalpy and entropy changes for the formation of methyl tert-butyl ether are −36.1 ± 2.6 kJ/mol and −73.8 ± 0.9 J/mol/K, and those for tert-butyl alcohol are −34.2 ± 2.8 kJ/mol and −86.5 ± 1.0 J/mol/K, respectively. These results are comparable to literature data.

Catalysis Studies of Macroreticular Polystyrene Cation‐exchange Resin with Terminal Perfluoroalkanesulfonic Acids

AbstractMacroreticular p‐(ω‐sulfonic‐perfluoroalkylated) polystyrene (FPS) resin with the advantages of both sulfonic polystyrene (such as macroreticular Amberlyst‐15) and perfluoroalkanesulfonic resin (such as superacidic Nafion NR50) has exhibited excellent catalytic selectivity and activity in cyclization of pseudoionone and condensation of indole. In this paper, FPS was characterized by XPS, nitrogen sorption technique, FESEM and Hammett indicator method, and employed as the solid acid catalyst in the esterification, acylation and alkylation reactions. The FPS resin showed better activity than commercial solid acid catalysts (Amberlyst‐15 and Nafion NR50) owing to its high surface area and strong acidity close to superacidity.

Integration of ion exchange and electrodeionization as a new approach for the continuous treatment of hexavalent chromium wastewater

Mining and electroplating wastewaters contain many harmful ions, which are discharged into waterways and water bodies and cause significant environmental damage. Hexavalent chromium (Cr(VI)) is an ion that is commonly present in these effluents, which has been proven as toxic to humans. In the present work, continuous ion exchange and electrodeionization are proposed as a new hybrid technology for the effective treatment of Cr(VI) wastewater as well as the recovery of chromium ions. We have systemically studied a strong basic macroreticular anion exchange resin (Amberlite® IRA900) for the removal of Cr(VI). The ion exchange isotherm and kinetics of the resin were determined, showing that the IRA900 anionic ion exchange resin has a high capacity for ion exchange with hexavalent chromium (116mg Cr(VI) per gram of resin). When the anionic resin was combined with a strong acidic macroreticular cation exchange resin (Amberlite® 200C) and employed in continuous electrodeionization, over 98.5% of Cr(VI) was continuously removed from the dilute compartment with an energy consumption of less than 0.07kWh/m3, while Cr(VI) was recovered in the concentrate compartment.

Alkylation of toluene with aliphatic alcohols and 1-octene catalyzed by cation-exchange resins

The catalytic activity of macroreticular cation-exchange resin (Amberlyst-15) was evaluated for the reaction of toluene with isopropanol, 1-octanol, 2-octanol and 1-octene at 80°C, in the liquid phase. The best results were achieved with octene. The reaction yielded only monoalkylation products. The conversion of octene was 75% after 4 h of reaction. In the reaction with isopropanol the main product was propene. In the reaction with 1-octanol and 2-octanol the conversion was very low and the main products were the octyl ethers.

Surface Complexation/Gouy−Chapman Modeling of Binary and Ternary Cation Exchange

The two-layer surface complexation model combined with the Gouy−Chapman model (SCGCM) was applied to describe and predict experimental data for cation adsorption and exchange on a synthetic resin. Knowledge of the surface properties of the sulfonate macroreticular cation-exchange resin was incorporated in the model. The data set included single, binary, and ternary cation adsorption involving Na, Mg, and Zn in single anionic media of chloride, perchlorate, and sulfate at 0.05 and 0.2 N in total cation concentration (TCC) and in their 1:1 binary mixtures at TCC = 0.05 N. The SCGCM exhibited reasonably good agreement with binary and ternary cation exchanges in the different anionic backgrounds and ionic strengths, based on constants extracted from fits of single cation adsorption data and a small set of binary exchange data. Specific adsorption was predicted to be dominant for the cation adsorption and exchanges on the resin studied in this work. Na was specifically adsorbed on the sulfonate group of the re...

Microscale Dehydration of Cyclohexanol Using a Macroreticular Cation Exchange Resin as Catalyst

There are few experiments for the undergraduate laboratory involving ion exchange resins as catalysts. In this experiment, cyclohexanol is dehydrated to cyclohexene using Amberlyst 15 macroreticular resin as an acid catalyst. The procedure is carried out with partners, one student using phosphoric acid-sulfuric acid catalyst, the other student using the resin. Yields and ease of manipulation between the two options are compared.

Intraparticle transport of amino acids in a cation exchanger

Intraparticle transport of amino acids, phenylalanine and tyrosine, in a macroreticular cation-exchange resin, Amberlite 200, was investigated in a finite batch adsorber. A transport model was developed based on the consecutive diffusion of the amino acids through liquid-filled macropores and microspheres. The latter was further simplified by the linear driving force approximation (LDFA) since the microspheres are quite small. The model was used satisfactorily for simulating and predicting the performance of finite batch operations.

Cation exchange resins in the synthesis of tert-alkyl ethers of 2-phenylethanol

Two useful perfumery compounds, tert-butyl ether and tert-amyl ether of 2-phenylethanol (PEA) were synthesized by the etherification of PEA with isobutylene gas and isoamylene, respectively, in the presence of macroreticular cation exchange resin as catalyst. A low reaction temperature and a clean method of synthesis and separation of the perfumery compounds have been shown by this work.

Synthesewege zu neuen ionischen Ozoniden

Synthetic Routes to New Ionic OzonidesNew synthetic routes to tetraorganylammonium ozonides involving exchange reactions with alkali metal ozonides were investigated. The previously reported reaction between tetraalkylammonium hyperoxides R4N+O2‐ (R = Me, Et) and alkali metal ozonides in liquid ammonia is severely hampered by the difficult synthesis of these hyperoxides; they are unknown for other quaternary ammonium cations. A similar reaction between the easily accessible chlorides of trialkylbenzylammonium ions and KO3 yields mixed ozonides/chlorides due to some solubility of KCl in liquid ammonia. The new compounds BzlMe3N+ (O3‐)0.6Cl‐0.4 (3), BzlEt3N+ (O3‐)0.8Cl0.2‐ (4) and Bzl(nBu)3N+(O3‐)0.5Cl0.5‐ (5) were prepared by this route. – The by far superior route to new ozonides utilizes macroreticular cation exchange resins in liquid ammonia. Batch equilibration between an excess of the appropriate ionic form of the resin and CsO3 produced Me3PhN+O3‐ (6), BzlMe3N+O3‐ (7), Bzl(nBu)3N+O3‐ (8), and (nPr)4N+ O3‐ (9) in almost quantitative yield. Compounds 4, 6, and 7 were studied by single‐crystal X‐ray analysis; the shortening of the ozonide bond length and the widening of the bond angle in comparison to the alkali metal ozonides as well as the possibility of C–H…O hydrogen bonding are discussed. Thermal stabilities were determined by DTA/TG methods, rapid decomposition starts at 59–79°C for 3, 6, and 7 and at 28–56°C for the remaining new ozonides which contain detachable β‐H atoms.

A Comparative Study of Gel-Type and Macroreticular Cation Exchange Resins for the Separation of Rare Earth Elements

Abstract Owing to the macro- and micro- pores in the matrix, macroreticular resins have larger micro-void volume ratio in the ion exchange column chromatography. It is advantageous in the ion exchange kinetics resulting from the quicker mass transfer. By means of EDTA displacement column chromatography for the Pr-Nd separation study, we have found that macroreticular cation exchange resins have higher separation efficiency in HETP, single stage time, and the pure Pr production rate, e. g. for AG 50W-X8, 200∼400 mesh resin (gel-type) and AG MP-50, 200∼400 mesh resin (macroreticular), the HETP values are 0.40 cm and 0.24 cm; the single stage times are 3.11 min and 1.30 min; the pure Pr production rates are 0.19 and 0.68 m mole/hr, respectively. Because both types of resins contain the same functional group, the single stage separation factors for Pr-Nd separation have the same value of 2.0±0.1 at 92°C. The cation exchange resins which were prepared in our laboratory with higher micro-void volume ratio could...

Ion exchange studies of U(VI), Th(IV), Pu(IV) and Eu(III) on a macroreticular resin in TBP-Shell Sol-T solutions

Ion exchange studies of uranium(VI), thorium(IV), plutonium(IV) and europium(III) ions on a macroreticular cation exchange resin, Amberlyst A-15, from solutions of 30% and 5% TBP—Shell Sol-T have been carried out. The metal ions were extracted into TBP Shell Sol-T phase from 8M NH4NO3 at different nitric acid concentrations. Ion exchange distribution ratios as a function of organic phase acidity of 30% and 5% TBP have been computed. Separation factors computed from the observed Kd values are plotted as a function of organic phase acidity.

Studies on selective adsorption resins. XXI. Preparation and properties of macroreticular chelating ion exchange resins containing phosphoric acid groups

AbstractMacroreticular cation exchange resins containing phosphoric acid groups (RGP) were prepared by the reaction of glycidyl methacrylate–divinylbenzene copolymer [or poly(glycidyl methacrylate)]beads (RG) with phosphoric acid or phosphorous oxychloride, and the adsorption behavior of metal ions on the RGP was investigated. The phosphorylation of the polymer beads could be effectively carried out by treatment of the polymer beads with 85% phosphoric acid at 80°C for 3 h. The RGP obtained from glycidyl methacrylate–divinylbenzene (2 mol %) copolymer beads showed high cation exchange capacity, salt splitting capacity, and adsorption capacity for Cu2+, Zn2+, Cd2+, Ca2+, and Ag+. On the other hand, the RGP obtained from poly(glycidyl methacrylate)beads had high adsorption capacity for Al3+, Fe3+, and UO22+. The RGP prepared by treating the RG with phosphoric acid had a higher selective adsorption for Li+ than for Na+.

Distribution coefficients and ion exchange behavior of 46 elements with a macroreticular cation exchange resin in hydrochloric acid

A systematic study of distribution coefficients in aqueous HCl using the macroreticular resin AG MP-50 was undertaken, and the results are here presented and discussed. Because cation exchange distribution coefficients are influenced quite strongly by the degree of cross linkage of the resin and this influence varies considerably depending on the size of the hydration shell of the cation in question, the rigid macroreticular resin with its very high effective cross linkage (about 25%) in the exchange region should show some marked differences in the distribution coefficients of some elements as compared with a 8% cross-linked gel-type resin. It has been shown that the distribution coefficient of magnesium when plotted against percentage of cross linkage shows a maximum at about 12% cross linkage and then slightly decreases again, while that for calcium shows an increase up to 25% cross linkage. As a result, the separation factor between Mg and Ca in 1M aqueous HCl increases from a value of about 2 with an 8% cross-linked gel-type resin to about 8 for the AG MP-50 macroreticular resin. It seems reasonable to assume that some other spectacular increases in separation factors are also possible.

Distribution coefficients and cation-exchange behaviour of 45 elements with a macroporous resin in hydrochloric acid/methanol mixtures

Cation-exchange distribution coefficients are presented for 45 elements with the macroreticular (macroporous) cation-exchange resin AG MP-50 in mixed hydrochloric acid/methanol media, with acid concentrations ranging from 0.5 to 6.0 M, and methanol concentrations from 0 to 90%. The ion-exchange behaviour of the elements is discussed, some possible separations are indicated, and 3 multi-element elution curves are presented, demonstrating the separations of the combinations In-Zn-Ga-Al-Yb; Cd-Li-Cu(II)-Mg-Ca; and Pt(IV)-Te(IV)-V(IV)-Fe(III)-Mn(II).

Ion Exchange of Th(IV), U(VI), and Pu(IV) on Macroreticular Resins in TBP-Shell Sol-T Solutions

Abstract Absorption of thorium, uranium, and plutonium by macroreticular cation and anion exchange resins from solutions of TBP in Shell Sol-T as a function of TBP and HNO3 concentrations in the organic phase has been investigated. The absoiption behavior is compared with that on conventional gel-type resins from TBP medium on the one hand and on macroreticular resins from aqueous nitric acid on the other.

High-performance liquid chromatography of peptides on a macroreticular cation-exchange resin: Application to peptide mapping of Bence-Jones proteins

A high-performance liquid chromatography system has been developed for analytical peptide mapping and preparative peptide separation. The method uses a macroreticular cation-exchange resin of the styrene-divinylbenzene type, having a relatively small particle size (6 ± 1 μm) and a high crosslinkage (35%). Elution was performed with a linear gradient of increasing salt and organic solvent concentration for monitoring the effluent at 210 nm. The system showed remarkable peak resolution and excellent mechanical and chemical stability, and high precision analysis of tryptic digests of S-aminoethyl Bence-Jones proteins was achleved in less than 120 min with nanomolar to micromolar quantities of the samples. The isolated peptides could be subjected to subsequent chemical determinations directly or after simple desslting process.

Cation-exchange chromatography of bismuth(III), cadmium(II), indium(III) and zinc(II) ions with hydrochloric acid in aqueous acetone solution

Trace amounts of bismuth(III), indium(III), cadmium(II) and zinc(II) were separated from each other by stepwise elution chromatography and detected by continuous flow spectromery. A macroreticular cation-exchange resin was used to achieve rapid separation in hydrochloric acid-acetone covering the acid and acetone concentration ranges 0.1–0.64 M and 18–80%, respectively.

Chromatographic separation of metal ions on a macroreticular cation-exchange resin with hydrochloric acid in mixed solvents

Forced-flow chromatography on a cation-exchange resin has been used to obtain separations of metal ions, such as Cu(II), Co(II), Mn(II), V(IV) and Ni(II). The macroreticular resin used provides rapid separations in hydrochloric acid containing organic solvents (tetrahydrofuran, 2-propanol—tetrahydrofuran, dimethyl sulphoxide, dimethylformamide or acetone—dimethylformamide).

Chromatographic separation of metal ions on a macroreticular cation-exchange resin with hydrochloric acid N aqueous acetone solution

Forced-flow chromatography on a cation-exchange resin has been used to obtain rapid separations of metal ions, such as Cd(II), Zn(II), Fe(III), Pb(II), Cu(II), Co(II) and Mn(II). The macroreticular resin used provides rapid separations in hydrochloric acid-acetone media covering acid and acetone concentration ranges of 0.1–1.88 M and 70–96%, respectively. On-stream addition of a colour-forming reagent provides continuous detection and quantitation of the eluted metals.

Transesterification of dmt with ethylene glycol catalyzed by amberlyst 15

AbstractThe catalytic effects of the macroreticular cation exchange resin Amberlyst 15 (H+) on the transesterification of dimethyl terepbthalate with ethylene glycol have been investigated in a batch reactor and at the temperature of 146°C with the aid of extensive chemical analysis. The resin exhibited significant intraparticle diffusion effects for the disappearance of dimethyl terephthalate and promoted the dehydration and subsequent etherification and polymerization reactions of ethylene glycol to a very significant extent. The side reactions of ethylene glycol rendered the transesterification process in the presence of Amberlyst 15 (H+) inefficient.