Thin-layer chromatography of oligomers

Belenky, B.G.; Valchikhina, M.D.; Vakhtina, I.A.; Gankina, E.S.; Tarakanov, O.G.

doi:10.1016/s0021-9673(00)87774-2

Cited by 42 publications

(17 citation statements)

References 13 publications

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“…Important progress in the separation of parent homopolymers from the diblock copolymers was brought about by the introduction of liquid chromatography under critical conditions of enthalpic interactions, LC CC, by Belenkii et al [6] In the LC CC column, the entropy (exclusion) controlled and the enthalpy (interaction) driven retention mechanisms mutually compensate each other and this results in the molar mass independent elution of macromolecules. The latter become ''chromatographically invisible''.…”

Section: Introductionmentioning

confidence: 99%

Separation of Parent Homopolymers from Diblock Copolymers by Liquid Chromatography under Limiting Conditions of Desorption, 2 ‐ Optimization of Experimental Arrangement

Berek¹

2008

Macro Chemistry & Physics

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The experimental arrangement for liquid chromatography under limiting conditions of desorption was optimized, aiming at separation of the parent homopolymers from diblock copolymers. Measurements with the block copolymer PS‐b‐PMMA have confirmed that the method enables fast and efficient separation of both parent homopolymers PS and PMMA from the copolymers in a single run. The new experimental set‐up also allows the separation of potentially present low molecular or oligomeric admixtures from the polymeric constituents of sample. The peak broadening of the non‐retained macromolecules has been suppressed. The sample recovery is high and can be easily checked by the injection of a large volume of an appropriate displacer.

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Section: Introductionmentioning

confidence: 99%

Separation of Parent Homopolymers from Diblock Copolymers by Liquid Chromatography under Limiting Conditions of Desorption, 2 ‐ Optimization of Experimental Arrangement

Berek¹

2008

Macro Chemistry & Physics

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“…The latter pores likely remain adsorptive in the course of their brief contact with the desorli zone. It is supposed that large macromolecules may decoil and reptate into narrow pores if their walls are attractive enough [39]. This may cause peak broadening and a drop in sample recovery because a part of sample is pulled into the pores and remains trapped within column packing [38].…”

Section: Polymers Injected Solutionsmentioning

confidence: 99%

Liquid chromatography of polymers under limiting conditions of adsorption: III. Role of experimental variables

Šnauko¹,

Berek²

2005

J of Separation Science

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LC of polymers under limiting conditions of adsorption (LC LCA) is a novel method based on different mobility of (pore excluded) macromolecules compared to (pore permeating) solvent molecules. Polymer sample is injected in a solvent preventing its adsorption within the column. Eluent promotes sample adsorption. Under these conditions, macromolecules cannot leave its initial solvent and elute from the column independently of their molar mass. In contrast, a less interactive simultaneously injected polymer leaves its initial solvent zone and is eluted in the size exclusion mode. As a result, chemically different polymer species can be discriminated. The effect of selected experimental conditions was studied on the LC LCA behavior of poly(methyl methacrylate)s eluted from bare silica gel columns. The parameters were packing pore diameter, injected sample volume and concentration, as well as column temperature. The size independent elution was only little affected by the above parameters and LC LCA produced well-focused peaks. The LC LCA mechanism was operative even at a very large sample of both volume and concentration. This makes LC LCA a robust and user-friendly method, likely suitable also for characterization of minor components of polymer mixtures.

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“…For example, liquid adsorption chromatography (LAC) has been studied by Mori [7] and was applied to analyze the chemical composition of statistical poly(styrene-co-methyl methacrylate) copolymers. So-called ''critical conditions'' have also been defined [13] and found to lead to an elution of homopolymers independent of their molar mass. In such experiments, the eluent corresponds to a mixture of a thermodynamically good solvent and a non-solvent for the macromolecules.…”

Section: Introductionmentioning

confidence: 99%

Characterization of Random Copolymers by Liquid Chromatography under Limiting Conditions of Adsorption

Sauzedde

Bartkowiak

Hunkeler

2006

International Journal of Polymer Analysis and Characterization

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Liquid chromatography under limiting conditions of adsorption (LC LCA) can be considered as a new tool to perform, simultaneously, molar mass and composition determination of statistical copolymers and to separate copolymer blends as a function of copolymer composition or microstructure. The suitability of LC LCA has been demonstrated for two series of statistical copolymers, poly(styrene-co-methyl methacrylate), poly(S=MMA), varying either in molar mass or composition. The binary eluent consisted of a mixture of n-hexane and THF, containing either 26 or 30 vol.% of n-hexane, respectively, for low and high LC LCA. Two parameters, the ratio of peak area over height and the ratio of peak area of chromatograms obtained by LC LCA and size exclusion chromatography (SEC), were employed to evaluate statistical copolymer elution through LC LCA. From the peak analyses, macromolecule recovery was complete over the entire composition and the molar mass ranges. LC LCA and SEC were further compared, and off-line fractionation was subsequently performed using a combination of both methods, with different statistical copolymer solutions having narrow, broad, and bimodal composition distributions.

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Thin-layer chromatography of oligomers

Cited by 42 publications

References 13 publications

Separation of Parent Homopolymers from Diblock Copolymers by Liquid Chromatography under Limiting Conditions of Desorption, 2 ‐ Optimization of Experimental Arrangement

Separation of Parent Homopolymers from Diblock Copolymers by Liquid Chromatography under Limiting Conditions of Desorption, 2 ‐ Optimization of Experimental Arrangement

Liquid chromatography of polymers under limiting conditions of adsorption: III. Role of experimental variables

Characterization of Random Copolymers by Liquid Chromatography under Limiting Conditions of Adsorption

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