Reactive Polymers

Lukáš, J.; Švec, František; Votavová, E.; Kálal, J.

doi:10.1016/s0021-9673(00)95497-9

Cited by 17 publications

(2 citation statements)

References 4 publications

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“…To evaluate the polarity of the modifi ed calcium aluminate and its capacity for certain kinds of intermolecular interactions, with benzene, methyl ethyl ketone, and pyridine as test compounds, we calculated Kovach's retention indices and Rohrschneider polarity coeffi cients with respect to Carbopack B [13]. The values of the coeffi cients for benzene (2.2), methyl ethyl ketone (6.1), and pyridine (5.3) indicate that modifi ed calcium aluminate has a substantial total polarity and tends to be involved in orientation and π-π interactions to form hydrogen bonds with sorbates, which is correlated with the results of the acid-base analysis of the surface of this sorbent.…”

Section: Resultsmentioning

confidence: 99%

Sol-gel synthesis and sorption properties of calcium monoaluminate

et al. 2016

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Method for synthesis of calcium aluminate and sorbents based on this compound was developed on its basis of the sol-gel technology. The method makes it possible to obtain the target product with specifi c surface areas in the range from 7 to 120 m 2 g -1 . The compounds obtained were characterized by scanning electron microscopy, X-ray phase analysis, and X-ray fl uorescence microanalysis. It was found that the main phase of the sorbents is rhombohedral calcium monoaluminate CaAl 2 O 4 . The method of Hammett indicator adsorption was used to determine the content of active centers on the surface of the sorbents and the distribution of these centers over ionization constants. It was shown that the surface characteristics of the sorbents depend on their synthesis method. The retention parameters, polarities, and thermodynamic characteristics were determined for organic compounds of various classes. The possibility of using calcium aluminate modifi ed with sodium chloride for gas-chromatographic separation of aliphatic and aromatic hydrocarbons and carbonyl compounds was demonstrated.The synthesis of calcium aluminate-based materials with prescribed structure and surface morphology attracts researchers' attention owing to the high thermal stability, mechanical strength, resistance to solvents of varied nature, and hydrolytic stability of these materials [1][2][3][4][5]. The sol-gel technique is one of promising ways to obtain oxide materials with certain size and shape of particles, with this method capable of varying the specifi c surface area and porosity of the substances being synthesized [6][7][8]. The possibility of forming porous substances with certain surface characteristics enables development of new promising functional materials with various properties and, in particular, sorbents for gas chromatography and supports modifi ed with inorganic substances.The goal of our study was to examine the structural and acid-base characteristics of the surface of calcium aluminate synthesized by the sol-gel method and the possibility of its application as a sorbent for gaschromatographic separation. EXPERIMENTALBased on an analysis of the experimental and published data [9, 10], we synthesized calcium aluminate of composition CaAl 2 O 4 by the sol-gel method with aluminum (Al 3+ ) nitrate nonahydrate, calcium (Ca 2+ ) nitrate tetrahydrate, and citric acid (H 4 Cit) monohydrate as starting substances. The amount of the reagents was calculated on the basis of the stoichiometric ratio Ca 2+ : Al 3+ : H 4 Cit = 1 : 2 : 3; all the components were of chemically pure grade. The starting substances were dissolved in the minimum amount of twice-distilled water and the solution was agitated for 1.5 for the complexation reaction to be complete. The resulting solution was heated until a gel was formed, and the gel was thermally treated at 130°C (SNOL 58/350 drying box) to remove the liquid phase and to form a xerogel. The fi nal stage of this synthesis consisted in calcination of the resulting precursor in an SNOL 6/1300 muffl e ...

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Section: Resultsmentioning

confidence: 99%

Sol-gel synthesis and sorption properties of calcium monoaluminate

et al. 2016

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“…[2][3][4] Macroporous hydrophilic copolymers based on glycidyl methacrylate (GMA) produced by radical suspension copolymerization in the shape of regular beads of the required size and porosity are widely used as column packing in GC, for heavy and platinum metal ion sorption, catalysis and biotechnological and biomedical applications. [5][6][7][8][9][10] In spite of this, only a few papers deal with inverse gas chromatography (IGC) investigations on the adsorptive properties of GMA based copolymers. [11,12] The IGC method has been extensively used for the investigation of polymer structure, the interactions of various liquids and gases with polymeric materials and polymer-polymer miscibility.…”

Section: Introductionmentioning

confidence: 99%

Characterization of Glycidyl Methacrylate Based Copolymers by Inverse Gas Chromatography under Finite Surface Coverage

Nastasović¹,

Onjia²,

Milonjić³

et al. 2005

Macro Materials & Eng

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Summary: Inverse gas chromatography under finite surface coverage conditions (IGC‐FC) was used for the investigation of sorption of hexane, benzene, chloroform and tetrahydrofuran on macroporous crosslinked poly[(glycidyl methacrylate)‐co‐(ethylene glycol dimethacrylate)], poly(GMA‐co‐EGDMA), and copolymer modified with ethylene diamine, EDA, poly(GMA‐co‐EGDMA)‐en, in the temperature range 333–363 K. Two poly(GMA‐co‐EGDMA) samples with different porosity parameters were synthesized by suspension copolymerization and modified using a ring‐opening reaction of the pendant epoxy groups with EDA. The specific surface areas of the initial and modified copolymer samples were determined by the BET method from low temperature nitrogen adsorption isotherms (77 K). The adsorption isotherms determined from chromatographic peaks of adsorbates were analyzed using the BET theoretical model and used for estimation of the surface area, isosteric heat of adsorption and the adsorption energy distribution on the surface of the initial and modified copolymer samples. It was observed that the adsorbate nature and the properties of the solid surface of the initial and modified copolymer governed the uptake of adsorbate by the copolymer. The deviations observed for the Sa values obtained by the BET method from the low temperature nitrogen adsorption isotherms and hexane was attributed not only to the difference in molecule size, but also to the specific polymer‐adsorbate interactions. The isosteric heat of adsorption approached a constant value with increasing adsorbate loading. A large variation in the shapes of the qst‐α curves resulted from strong acid‐base interactions, as well as dissolution phenomena. Of the four studied adsorbates, chloroform was shown to have the greatest affinity towards the surface of the investigated polymer samples.Adsorption isotherms of hexane on sample 1 and 1a.magnified imageAdsorption isotherms of hexane on sample 1 and 1a.

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Chelatbildende lonenaustauscher auf Basis makroporöser Glycidylmethacrylat‐Ethylendimethacrylat‐Copolymere: Herstellung, Eigenschaften und Anwendung

Švec¹

1980

Acta Polymerica

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Eine Übersicht über Herstellung, Eigenschaften und Anwendung von chelatbildenden Ionenaustauschern auf Basis makroporöser Glycidylmethacrylat‐Ethylendimethacrylat‐Copolymere wird gegeben. Es wird gezeigt, welche Parameter bei der Herstellung der Matrix zu beachten sind und wie diese auf die Struktur der Copolymere einwirken. An einigen Beispielen werden die zahlreichen Möglichkeiten der Umsetzung der Epoxygruppe demonstriert und die chelatbildenden Eigenschaften der resultierenden Harze beschrieben.

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Reactive Polymers

Cited by 17 publications

References 4 publications

Sol-gel synthesis and sorption properties of calcium monoaluminate

Sol-gel synthesis and sorption properties of calcium monoaluminate

Characterization of Glycidyl Methacrylate Based Copolymers by Inverse Gas Chromatography under Finite Surface Coverage

Chelatbildende lonenaustauscher auf Basis makroporöser Glycidylmethacrylat‐Ethylendimethacrylat‐Copolymere: Herstellung, Eigenschaften und Anwendung

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