Reactive polymers, 49. Changes in the porous structure of macroporous copolymers due to successive effects of solvents and temperature

Hradil, J.; Švec, F.

doi:10.1002/apmc.1985.051300106

Cited by 24 publications

(10 citation statements)

References 8 publications

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“…This is because, it enters into a large number of chemical reactions by oxirane ring opening, thus offering the opportunity for chemical modification of the pendant copolymers for various applications such as immobilization of enzymes, DNA, catalysts, and biomolecules. 25,26 In this work, the copolymers of GMA and MTM were prepared in DMF by varying the molar ratios of the monomers in the feed.…”

mentioning

confidence: 99%

Copolymers of Glycidyl Methacrylate with 3-Methylthienyl Methacrylate: Synthesis, Characterization and Reactivity Ratios

Günaydın

Yılmaz

2007

Polym J

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ABSTRACT:Homo-polymers of glycidyl methacrylate (GMA) and 3-methylthienyl methacrylate (MTM) and their copolymers in various compositions were prepared by free radical polymerization in dimethyl formaldehyde (DMF) solution at 60 C using , 0 -azobisisobutyronitrile (AIBN) as an initiatior. The copolymers, poly(GMA-co-MTM), were characterized by 1 H NMR and 13 C NMR spectroscopic techniques. 1 H NMR analysis was used to determine the copolymer compositions. The molecular weights (M w and M n ) and polydispersity indices of the copolymers were determined by gel permeation chromatography (GPC). Thermal behavior of the copolymers was also investigated by thermogravimetrical analysis (TGA) and differential scanning calorimetry (DSC). Monomer reactivity ratios were determined for low conversion using Fineman Ross (FR) (r GMA ¼ 0:9795; r MTM ¼ 0:5641) and Kelen Tüdós (KT) (r GMA ¼ 0:9796; r MTM ¼ 0:5771) graphical methods. In both cases, r 1 r 2 is less than 1, indicating that the copolymer deviates slightly from ideal copolymerization.

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confidence: 99%

Copolymers of Glycidyl Methacrylate with 3-Methylthienyl Methacrylate: Synthesis, Characterization and Reactivity Ratios

Günaydın

Yılmaz

2007

Polym J

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“…The latter behavior has now been well characterized with very light cross-linked (<5 wt % DVB) resins prepared with a poor porogen, and these species have been designated as "reversibly collapsible" porous resins. 12,13 Considering next the extensive series of resins M.T.60-0 to M.T.60-20 prepared with 60 wt % DVB, toluene as the porogen and increasing levels of DDT transfer agent. First there is again good evidence from the S% content for incorporation of residues of the DDT transfer agent into resins.…”

Section: Resultsmentioning

confidence: 99%

“…[9][10][11] We have, however, previously probed the interface between these two morphological extremes and demonstrated that collapsible macroporous resins can be prepared with some of the favorable characteristics of both resin types. 12,13 Inevitably a given morphology imposes some limitations on a resin, the most important in the case of gel-type resins being the requirement to employ solvents which are thermodynamically compatible and hence which swell the gel matrix. In the case of macroporous resins a common limitation is that some functional groups within the highly cross-linked gel phase of the resin are inaccessible or impose some mass transport limitation on their exploitation.…”

Section: Introductionmentioning

confidence: 99%

One-Pot Synthesis of Branched Poly(styrene−divinylbenzene) Suspension Polymerized Resins

et al. 2002

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Spherical particulate polymer resins have become ubiquitous support materials in both solid phase synthesis and in the heterogenizing of homogeneous catalysts. In the former case lightly cross-linked so-called gel-type species are favored whereas in the latter so-called macroporous species are finding increasing utility. Despite the success of these materials, mass transfer limitations can lead to poor performance, and in this context there is still a need for improvement in the morphology of these species. One potential advancement would be resins with a highly branched backbone architecture since such a molecular level structure would in principle generate a large proportion of functional groups near chain ends or at least on mobile chains anchored to the main matrix by a single linkage. In addition a high level of chain ends relative to that in conventional resins might lead to novel solvation characteristics. We now report a facile one-pot suspension polymerization which allows synthesis of both branched gel-type and branched macroporous resins. The procedure is an adaptation of our earlier reported methodology for producing soluble branched vinyl polymers and involves use of controlled levels of a free radical chain transfer agent which functions in effect to limit chain growth and in combination with a cross-linking comonomer leads essentially to branched backbone architectures. The system styrene/ divinylbenzene/dodecanethiol has been probed in detail, and a range of experimental conditions have been identified which lead to branched gel-type and branched macroporous resins. The structure of these has been evaluated from solvent swelling data, dry state surface area measurements, and inverse size exclusion chromatographic data.

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“…Post-crosslinked resins (so called macronetworks or also termed hypercrosslinked or isoporous polymers) are obtained by crosslinking linear polymers or swelled gel-type or macroporous resins using Friedel-Crafts alkylation or acylation. Typical crosslinking agents for polystyrene or low-crosslinked styrenedivinylbenzene copolymers include chloromethyl methyl (or ethyl) ether (30), (31), chloromethyl polyethers (32), p-xylylene dichloride (33), (34), (36), l,4-bis-(4-chloromethylphenyl)butane (36), sulfur halides (37), and tetrachloromethane (38). As the catalysts, tin(IV), iron(III) and titanium(IV) chlorides are used.…”

Section: Polymer As a Porogen Agentmentioning

confidence: 99%

Packings for Size Exclusion Chromatography: Preparation and Some Properties

Horák

Hradil

Beneš

1996

ACS Symposium Series

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Materials used as packings in size-exclusion chromatography can be divided into organic and inorganic ones. Organic packings include both synthetic and natural products. The preparation of these matrices, the mechanism of porous structure formation, depending on synthesis conditions, as well as the properties of packings, are reviewed.Since the column is the heart of any chromatographic system, the choice of packing greatly affects the success of any analysis. The basic requirements for the packing material for size-exclusion chromatography (SEC) columns include chemical inert ness and minimal adsorption of separated compounds so that the retention may be strictly based on hydrodynamic volume. Further requirements include high porosity which can be either permanent in macroporous resins, or swelling in low-crosslinked polymers. In addition to the chemical properties, the importance of physical pro perties such as the particle size must be stressed to achieve an adequate resolution of the packing. The particles should be spherical and uniform in size to minimize mass transfer limitations. Since the column separation efficiency increases with decreasing particle size, the size should be as small as possible, however, with good flow properties. High-speed, high-resolution chromatography also sets special re quirements for geometrical and mechanical properties. They play a decisive role in the lifetime of the packing and the stability of the flow-rates through the column. It is therefore desirable that all the factors outlined above should be taken into account when choosing the packing. Generally, packings can be divided into universal and those that have a specific effect or "tailor-made" packings. A universal packing covers a broad molecular-weight distribution of the components of an unknown sam ple. Such preliminary assessment allows the subsequent choice of a resin that has the optimum properties for a given separation problem.Chromatographical packings have been already systematically reviewed in many papers and monographs (7-9). The aim of article is to review the synthesis, morphology and other properties of packings which are important for SEC.

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Reactive polymers, 49. Changes in the porous structure of macroporous copolymers due to successive effects of solvents and temperature

Cited by 24 publications

References 8 publications

Copolymers of Glycidyl Methacrylate with 3-Methylthienyl Methacrylate: Synthesis, Characterization and Reactivity Ratios

Copolymers of Glycidyl Methacrylate with 3-Methylthienyl Methacrylate: Synthesis, Characterization and Reactivity Ratios

One-Pot Synthesis of Branched Poly(styrene−divinylbenzene) Suspension Polymerized Resins

Packings for Size Exclusion Chromatography: Preparation and Some Properties

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