Fractionation of Polymers by Thin-Layer Chromatography. III. Phase Separation and Thin-Layer Gel Permeation Chromatography

Otocka, E. P.; Hellman, M. Y.; Muglia, P. M.

doi:10.1021/ma60026a024

Cited by 17 publications

(6 citation statements)

References 2 publications

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“…Recently efforts in three separate laboratories have been successful in determining the molecular weight distribution of a polymer sample by TLC techniques (9)(10)(11)(12). An explana tion of the facility and high resolving power observed has been sought through a number of continuing experiments (11)(12)(13)(14)(15)(16). The purpose of this report is to review the results of these studies and to comment on the fractionation mechanisms postulated.…”

Section: Thin-layer Chromatography (Tlc) Is a Common Laboratory Technmentioning

confidence: 93%

“…More recently, Otocka measured the Rf* values for several polysty renes using dioxane-methanol and dioxane-2-propanol θ solvents (16). The results shown in Table I The adsorption concept of fractionation cannot account for the fact that samples reach a constant position from the dip line or that the nature of the substrate is unimportant in determining the retardation of sample migration.…”

Section: Polymer Journalmentioning

confidence: 96%

“…Recent work has indicated that thin-layer gel permeation chroma tography (TLGPC) is possible on wet plates (16). The resolution is much less than for the conventional TLC approach.…”

Section: Polymer Journalmentioning

confidence: 99%

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Thin-Layer Methods for Determining Molecular Weight Distribution

Otocka¹

1973

Polymer Molecular Weight Methods

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Thin-layer chromatography (TLC) is a common laboratory technique for separating complex mixtures of solutes, usually by an adsorbtion mechanism. Several laboratories have applied the technique to the separation of polymer fractions and characterization of polymer molecular weight distribu tions. This work reviews the experimental results and theoretical approaches to the fractionation mechanisms.^phin-layer chromatography (TLC) is a well-known technique for the separation of mixed solutes by adsorption. Compared with related techniques in column chromatography, TLC offers several advantages. The use of adsorbents having large surface area ( particle size ~10 μ vs. 50 μ) results in excellent resolution. Separation and analysis time are reduced because many samples can be run simultaneously and material need not be eluted for quantitation. Several references provide a com prehensive background on TLC ( 1-3 ).TLC has been a widely accepted technique in biochemistry and or ganic chemistry for a number of years. With modern quantitation TLC is being used today in such diverse applications as air pollution analysis and clinical medicine.The initial applications of TLC to problems in polymer chemistry were directed to the separation of polymer blends, stereoisomers, and a variety of copolymers ( 4-8 ). From these investigations occasional molec ular weight effects were noted (8). Recently efforts in three separate laboratories have been successful in determining the molecular weight distribution of a polymer sample by TLC techniques (9-12). An explana tion of the facility and high resolving power observed has been sought through a number of continuing experiments (11)(12)(13)(14)(15)(16). The purpose of this report is to review the results of these studies and to comment on the fractionation mechanisms postulated. 55Downloaded by UCSF LIB CKM RSCS MGMT on December 2, 2014 |

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Section: Thin-layer Chromatography (Tlc) Is a Common Laboratory Technmentioning

confidence: 93%

Section: Polymer Journalmentioning

confidence: 96%

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Thin-Layer Methods for Determining Molecular Weight Distribution

Otocka¹

1973

Polymer Molecular Weight Methods

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“…Differences in thermogravimetric analysis decomposition of a urethane polymer derived from 2,4-toluene diisocyanate and a polyol at different heating rates were confirmed by the appearance of a second DTA peak at the higher heating rates (74). Methacrylate polymers were separated by TLC (70) and polyethylene by TLC-gel permeation (87). A computer program was established .which served to identify unknown materials using six major IR absorption bands for a series of vinyl polymers and copolymers (52).…”

Section: General Analytical Schemesmentioning

confidence: 99%

Coatings

Esposito¹,

Adams²

1975

Anal. Chem.

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This review includes analytical methods of coating interest that have appeared in the literature since the last published survey (112), or were not included in the previous review, and it covers the literature through November 1974. Some selectivity has been exercised to include only those procedures especially pertinent or those, which in the authors' judgment could be adapted easily to analytical coating problems.A number of books on various phases of coating analysis have been published in this two-year period. In previous years, ASTM Standards on paint were included in parts 20 and 21 of the "Annual Book". However, in 1974, all of the ASTM standards on paint and related products were published in volumes 27-29. Part 27 ( 4 ) contains 190 standards of which 37% are new, revised, or changed in status. Part 28 (5) contains 140 standards of which 24% are new, revised, or changed in status. Among the new standards in this volume are a recommended practice for qualitative identification of polymers in emulsions, chemical analysis of phthalocyanine blue and green pigments, and analysis of white zinc pigments. Volume 29 ( 6 ) includes 240 standards, 12% which are new, revised, or changed in status, and contains a new test for aromatics in mineral spirits by gas chromatography (GC).Haken's book, (41), "Gas Chromatography of Coating Materials," covers the GC analysis of a broad range of raw materials and finished coatings. Litchfield published a monograph (62) describing the chromatographic analysis of triglycerides. A book by Crippen (25) emphasized the combination of organic functional group analysis along with GC retention data and solubility studies for the identification of organic compounds, many being of coatings significance. "Experiments in Polymer Science" (21 ) contained experiments for determining molecular weight distribution, morphology, and thermal properties of polymers. Haslam et al. (48) published a second edition of "Identification and Analysis of Plastics." This edition contains a new 80-page chapter entitled, "Instrumentation Methods"; the remaining chapters are similar to those in the first edition. "Gas Chromatography in the Chemistry of Polymers" (10) covered fundamentals of GC, monomer, and solvents analysis. Other chapters deal with kinetics and reactions of high polymer formation, and the determination of unreacted monomers, pyrolytic GC, and the analysis of additives. The GC analysis of terpenes was described in "Advances in Chromatography'' by Giddings and Keller (37).During the period since the previous Coatings Review, very significant advances have been made in high-efficiency liquid chromatography (HELC) using controlled flow at high pressure, continuous detection, and small particle size column packing material. The modes of separation are based on adsorption, partition, ion-exchange, and molecu-Authors have not been supplled with free reprints for free distribution. Extra coples of the revlew issue may be obtalned from Special issues Sales, ACS, 1155 16th St., N.W., Washlngton, DC 2...

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“…In contrast, very few methods have been developed or applied in the last years related to the characterization of polymers themselves [5]. We face a paradox: whilst a reliable HPTLC technology is currently available but there is almost no research activity in polymer characterization, a number of theoretical and experimental applications were proposed in the 70-90s [6][7][8][9][10][11][12][13][14][15][16][17][18], when TLC technology had not yet reached an adequate stage of development.…”

Section: Introductionmentioning

confidence: 99%

Revisiting molecular weight distribution of polystyrenes using adsorption high-performance thin-layer chromatography

Jarne

Cebolla

Membrado

et al. 2013

Journal of Planar Chromatography – Modern TLC

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A repeatable separation of polystyrenes according to MW, from 1920 to 520000 u.m.a, has been obtained under adsorption conditions using a method that comprises the use of Lichrospher HPTLC plates, and a controlled, isocratic elution with a 78:22 (v/v) mixture of cyclohexane (Cy)-tetrahydrofuran (THF).Likewise, UV-densitometric quantification of polystyrenes in mixtures can be achieved, by an intra-plate or an inter-plate procedure, using the corresponding polystyrene calibration curve. In the case or overlapped, unresolved peaks, an average curve of the corresponding polystyrenes can be used. Migration of polystyrenes strongly varies with slight variations in the relative proportion of Cy and THF in the mobile phase. This allows different ranges of MW to be separated as a function of mobile phase composition. Other factors influencing repeatability have been identified. Some reasons have been advanced to explain the current lack of activity in the research on polymer characterization by HPTLC. Old literature results concerning polystyrene separation have also been discussed in the light of modern HPTLC instrumentation.Developed method provides similar information on Molecular Weight Distribution (MWD) to that obtained using Gel Permeation Chromatography (GPC). Advantages and limitations of HPTLC for obtaining polymer MWD have also been discussed.

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Fractionation of Polymers by Thin-Layer Chromatography. III. Phase Separation and Thin-Layer Gel Permeation Chromatography

Cited by 17 publications

References 2 publications

Thin-Layer Methods for Determining Molecular Weight Distribution

Thin-Layer Methods for Determining Molecular Weight Distribution

Coatings

Revisiting molecular weight distribution of polystyrenes using adsorption high-performance thin-layer chromatography

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