Separation analysis of polyisoprenes regarding microstructure by online LCCC-NMR and SEC-NMR

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dc.contributor.authorHiller W.
dc.contributor.authorSinha P.
dc.contributor.authorHehn M.
dc.contributor.authorPasch H.
dc.contributor.authorHofe T.
dc.date.accessioned2011-05-15T15:59:55Z
dc.date.available2011-05-15T15:59:55Z
dc.date.issued2011
dc.description.abstractIt is shown that online coupling of liquid chromatography at critical conditions (LCCC) and 1H NMR spectroscopy can be used to separate and analyze polyisoprenes with respect to their isomeric microstructures. It was possible to separate blends of copolymers consisting predominantly of 3,4- and 1,4-isoprene units by using critical conditions of 1,4-PI. Critical conditions of 1,4-PI were established such that polymers containing predominantly 3,4-PI elute in the size exclusion mode. Furthermore, on-flow NMR detection allows for the complete eluate analysis and the detection of all three isomeric species, such as 1,2-, 1,4-, and 3,4-isoprene, in the eluting fractions. These three individual moieties were correctly quantified in the individual blend components. It was also found that the 3,4-PI samples were random terpolymers of 1,2-, 1,4-, and 3,4-isoprene, whereas the 1,4-PI samples were copolymers of 1,4- and 3,4-isoprene. In addition, SEC-NMR allowed for a fast and precise molar mass calibration and the calculation of the relevant molar mass parameters Mw and Mn. © 2011 American Chemical Society.
dc.description.versionArticle
dc.identifier.citationMacromolecules
dc.identifier.citation44
dc.identifier.citation6
dc.identifier.issn249297
dc.identifier.other10.1021/ma102750s
dc.identifier.urihttp://hdl.handle.net/10019.1/11428
dc.subjectBlend components
dc.subjectCritical condition
dc.subjectH NMR spectroscopy
dc.subjectIsomeric species
dc.subjectLiquid chromatography at critical conditions
dc.subjectMass calibrations
dc.subjectMass parameter
dc.subjectOn-line coupling
dc.subjectSeparation analysis
dc.subjectSize exclusion mode
dc.subjectChromatography
dc.subjectCopolymerization
dc.subjectMicrostructure
dc.subjectNuclear magnetic resonance spectroscopy
dc.subjectTerpolymers
dc.subjectGel permeation chromatography
dc.titleSeparation analysis of polyisoprenes regarding microstructure by online LCCC-NMR and SEC-NMR
dc.typeArticle
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