Separation of stereospecific polymers with respect to their steric isomerism by thin layer chromatography

Inagaki, Hiroshi; Miyamoto, Takeaki; Kamiyama, Fumio

doi:10.1002/pol.1969.110070501

Cited by 46 publications

(19 citation statements)

References 10 publications

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“…[39] Berek et al attempted to separate PMMA with regard to tacticity using LC at limiting conditions on bare silica stationary phases. While there were slight differences in the curves of different stereoregular PMMAs, unfortunately, the Figure 5.…”

Section: Microstructure Analysis By Column-based Fractionationsmentioning

confidence: 99%

Advanced fractionation methods for the microstructure analysis of complex polymers

Pasch

2015

Polymers for Advanced Techs

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This review discusses some recent work on the microstructure analysis of complex polymers using advanced fractionation methods. Complex polymers are distributed in a number of molecular parameters including molar mass, chemical composition, molecular architecture, and microstructure. Molar mass and chemical composition analysis is typically conducted by a range of spectroscopic and chromatographic methods, size exclusion chromatography and high-performance liquid chromatography (HPLC) being the most important fractionation methods. It is shown that HPLC is also very sensitive regarding polymer microstructure and can be used for the fractionation of e.g. polymethacrylates, polyisoprene, and polybutadiene. The best approach to the quantitative analysis of microstructure distributions is the on-line coupling of the fractionation with 1 H nuclear magnetic resonance spectroscopy. The spectroscopic analysis of chromatographic fractions provides concentration profiles of the tactic units as a function of the chromatographic separation and can be used for both HPLC and size exclusion chromatography. Apart from column-based fractionations, channel-based fractionations such as thermal field flow fractionation are powerful tools for microstructure analysis of complex polymers. It has been shown very recently that thermal field flow fractionation is capable of fractionating polyisoprene and polybutadiene according to microstructure.

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Section: Microstructure Analysis By Column-based Fractionationsmentioning

confidence: 99%

Advanced fractionation methods for the microstructure analysis of complex polymers

Pasch

2015

Polymers for Advanced Techs

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“…The addition of 1-% THF to the polymerization in toluene caused a decrease of isotacticity accompanied with an increased syndiotacticity, and the polymer obtained at -78°C, was found to be a mixture of isotactic and syndiotactic polymers by the thin-layer chromatogram of the PMMA derived from it. 10…”

Section: Polymerization Of Dmbmamentioning

confidence: 99%

“…The isotacticity of Part I was lower than that of Part II, particularly for the polymers obtained at -40 and 0°C. It was found from thin-layer chromatography 10 that Part I, which originated from the copolymer prepared at 0°C, was a mixture of isotactic and syndiotactic polymers, while Part II appeared to be rather homogeneous in stereoregularity. The copolymerization of MMA and DMBMA in THF was also carried out by n-BuLi (Table IV).…”

Section: Copolymerization Of Mma and Dmbma By N-bulimentioning

confidence: 99%

Polymerization of α,α-Dimethylbenzyl Methacrylate and Its Copolymerization with Methyl Methacrylate by Anionic Initiators

Yuki

Ohta

Hatäda

1977

Polym J

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a,a-Dimethylbenzyl methacrylate (DMBMA) was polymerized by anionic initiators and the tacticities of the polymers were determined from the PMR spectra of poly(methyl methacrylate)s derived from them. By butyllithium (11-BuLi), an isotactic polymer was obtained in toluene and a syndiotactic one in tetrahydrofuran (THF). Grignard reagents gave isotactic polymers in good yields. DMBMA was copolymerized with methyl methacrylate (MMA) by n-BuLi in toluene and THF. The copolymerization in toluene produced two kinds of copolymers: one was the usual copolymer, and the other predominantly consisted of MMA over 90% and was a mixture of isotactic and syndiotactic polymers. The stereoregularity of the copolymer obtained in THF was close to that of the homopolymer of DMBMA. KEY WORDS

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“…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)(5)(6)(7)(8). From these investigations occasional molec ular weight effects were noted (8).…”

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

confidence: 99%

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 |

show abstract

Separation of stereospecific polymers with respect to their steric isomerism by thin layer chromatography

Cited by 46 publications

References 10 publications

Advanced fractionation methods for the microstructure analysis of complex polymers

Advanced fractionation methods for the microstructure analysis of complex polymers

Polymerization of α,α-Dimethylbenzyl Methacrylate and Its Copolymerization with Methyl Methacrylate by Anionic Initiators

Thin-Layer Methods for Determining Molecular Weight Distribution

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