Characterization of high molecular weight polyethylenes using high temperature asymmetrical flow field-flow fractionation with on-line infrared, light scattering, and viscometry detection

Mes, E.P.C.; Jonge, H. de; Klein, Thorsten; Welz, Roland; Gillespie, David

doi:10.1016/j.chroma.2007.03.116

Cited by 57 publications

(32 citation statements)

References 51 publications

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“…For that, MALS, differential refractive index (dRI), UV/Vis, and dynamic light scattering (DLS) are commonly applied [177]. Additional information on similar parameters could be delivered by differential viscometer [178], and structure and molecular composition can be further investigated by coupling AF4 to nuclear magnetic resonance (NMR) [179] and FT-IR [180].…”

Section: Separation Principlementioning

confidence: 99%

Size Separation Techniques for the Characterisation of Cross-Linked Casein: A Review of Methods and Their Applications

et al. 2018

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Abstract:Casein is the major protein fraction in milk, and its cross-linking has been a topic of scientific interest for many years. Enzymatic cross-linking has huge potential to modify relevant techno-functional properties of casein, whereas non-enzymatic cross-linking occurs naturally during the storage and processing of milk and dairy products. Two size separation techniques were applied for characterisation of these reactions: gel electrophoresis and size exclusion chromatography. This review summarises their separation principles and discusses the outcome of studies on cross-linked casein from the last~20 years. Both methods, however, show limitations concerning separation range and are applied mainly under denaturing and reducing conditions. In contrast, field flow fractionation has a broad separation range and can be easily applied under native conditions. Although this method has become a powerful tool in polymer and nanoparticle analysis and was used in few studies on casein micelles, it has not yet been applied to investigate cross-linked casein. Finally, the principles and requirements for absolute molar mass determination are reviewed, which will be of increased interest in the future since suitable calibration substances for casein polymers are scarce.

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Section: Separation Principlementioning

confidence: 99%

Size Separation Techniques for the Characterisation of Cross-Linked Casein: A Review of Methods and Their Applications

et al. 2018

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“…The authors mentioned the possibility to separate PE by HT-AF4 [86]. In the SEC measurements a high molar mass shoulder appeared in the chromatogram for the LDPE samples, which was not observed in the associated fractograms (Fig.…”

Section: Field Flow Fractionationmentioning

confidence: 97%

“…Generally, a dissolution time between 1 and 6 h at a temperature of C is recommended. During the dissolution process, the sample may be shaken or stirred [85][86][87][88]. For protection against thermo-oxidative degradation, phenolic antioxidants (e.g., butylated hydroxytoluene) are usually added in concentrations of 0.2 mg/mL [87] up to 1.5 mg/mL [88] to the solvent.…”

Section: Size Exclusion Chromatographymentioning

confidence: 99%

“…Care must be taken to avoid the presence of oxygen, vigorous stirring and sample filtering because this may lead to sample degradation. Polyolefin chains may degrade during sample preparation or during the SEC separation itself [85,86,89]. The thermooxidative degradation and the chain scission due to shear stress in the SEC column are the main sources for the potential reduction of the polyolefin molar masses [85,87].…”

Section: Size Exclusion Chromatographymentioning

confidence: 99%

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Recent Advances in High-Temperature Fractionation of Polyolefins

Pasch

Malik

Macko³

2012

Advances in Polymer Science

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“…[27,[36][37][38][39][40] Now a new AF4 system is commercially available which is able to operate at temperatures above 130 8C. [2,3,17,41] This makes the advantages of FFF applicable for the characterization of POs. In AF4 the polymer is separated by a cross-flow field according to the diffusion coefficient of the macromolecules or particles.…”

Section: Introductionmentioning

confidence: 99%

Visualization of Thermo‐Oxidative Degradation of Polyolefins in Solution Using HT‐SEC and HT‐AF4‐MALS

Otte

Pasch

Brüll³

et al. 2011

Macro Chemistry & Physics

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The molar mass distributions of high‐molar‐mass PE and PP were characterized using HT‐AF4 and HT‐SEC in combination with IR and MALS detection. Calculated molar mass distributions, average molar masses and radii of gyration were compared. It was found that HT‐AF4 can detect the real extent of thermo‐oxidative degradation during dissolution. HT‐SEC is affected by shear and thermo‐oxidative degradation while in HT‐AF4 no shear stress exists. As a consequence, the molar mass averages obtained from HT‐SEC are pronouncedly lower as obtained from HT‐AF4. In addition, branched polyolefins cannot be correctly characterized by SEC‐MALS due to abnormal co‐elution effects. HT‐AF4 is therefore the method of choice for studying the thermo‐oxidative degradation of macromolecules with high molar masses. magnified image

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Characterization of high molecular weight polyethylenes using high temperature asymmetrical flow field-flow fractionation with on-line infrared, light scattering, and viscometry detection

Cited by 57 publications

References 51 publications

Size Separation Techniques for the Characterisation of Cross-Linked Casein: A Review of Methods and Their Applications

Size Separation Techniques for the Characterisation of Cross-Linked Casein: A Review of Methods and Their Applications

Recent Advances in High-Temperature Fractionation of Polyolefins

Visualization of Thermo‐Oxidative Degradation of Polyolefins in Solution Using HT‐SEC and HT‐AF4‐MALS

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