Determination of functionality and molecular weight distributions in α‐hydroxy‐ω‐benzyloxyoligo(1,3,6‐trioxocane)s using HPLC methods

Krüger, Hartmut; Much, Helmut; Schulz, Günter; Wehrstedt, Carla

doi:10.1002/macp.1990.021910417

Cited by 13 publications

(4 citation statements)

References 6 publications

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“…Other examples of successful combinations with MALDI-MS are given by Krüger et al [20,64]. Linear and cyclic fractions of polylactides can be separated.…”

Section: Chemical Composition Of Polymersmentioning

confidence: 97%

MALDI-TOF mass spectrometry in the analysis of synthetic polymers

1998

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“…Other examples of successful combinations with MALDI-MS are given by Krüger et al [20,64]. Linear and cyclic fractions of polylactides can be separated.…”

Section: Chemical Composition Of Polymersmentioning

confidence: 97%

MALDI-TOF mass spectrometry in the analysis of synthetic polymers

1998

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“…For fractions 2 and 3 by determining the degree of polymerization of the oligomer peaks oligomer calibration curves were obtained, which were used for the molar mass calculation of the fractions. Other examples of successful combinations of liquid chromatography and MALDI-TOF have been reported by Krüger et al who separated linear and cyclic fractions of polylactides by LC-CC [184]. Just et al were able to separate cyclic siloxanes from linear silanols and to characterize their chemical composition [185].…”

Section: Coupling With Mass Spectroscopymentioning

confidence: 98%

Hyphenated Techniques in Liquid Chromatography of Polymers

Pasch

2000

New Developments in Polymer Analytics I

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Complex polymers are distributed in more than one direction of molecular heterogeneity. In addition to the molar mass distribution, they are frequently distributed with respect to chemical composition, functionality, and molecular architecture. For the characterization of the different types of molecular heterogeneity it is necessary to use a wide range of analytical techniques. Preferably, these techniques should be selective towards a specific type of heterogeneity. The combination of two selective analytical techniques is assumed to yield two-dimensional information on the molecular heterogeneity.The present review presents the principle ideas of combining different analytical techniques in two-dimensional analysis schemes. Most promising protocols for hyphenated techniques refer to the combination of two different chromatographic methods and the combination of chromatography and spectroscopy. This review will discuss the basic principles of two-dimensional chromatography and the hyphenation of liquid chromatography with selective detectors.

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“…Besides the determination of the functionality-type distribution, LC in the critical mode has also been applied to separate polymer blends (Pasch, 1993), to study AB and ABA block copolymers (Pasch et al, 1993; Pasch and Augenstein, 1993) to study branching or grafting (Gorschkov et al, 1988) to separate linear macromolecules from cyclic analogous (Entciis et al, 1986;Kruger et al, 1990) o r to separate block from random copolymers (Gorshkov et al, 1990). A pictural overview (Skvortsov and Gorbunov, 1990) of the different types of macromolecules which can be studied with critical LC is shown in Fig.…”

Section: The Critical Mode In Polymer Liquld Chromatographymentioning

confidence: 99%

Microcolumn liquid chromatography of macromolecules in the critical mode

Damme¹,

Streck²

1995

Biomedical Chromatography

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THE CRITICAL MODE IN POLYMER LIQUlD CHROMATOGRAPHYIt is well known that by changing the eluent composition in the liquid chromatographic (LC) analysis of macromolecules, one can go from the exclusion mode to the adsorption mode, resulting in an opposite elution order of the studied macromolecules. In between this exclusion and adsorption region, there is a so-called 'Critical Region' wherc the polymer backbone does not contribute to retention (Entelis et al., 1986). By employing the specific eluent composition and temperature corresponding to this critical region, the retention of macromolecules will be determined by the number and polarity of the chain-endgroups only. The polymer backbone has become 'invisible' to the adsorbent and the macromolecule elutes as if it were a point-like molecule with the endgroups being responsible for retention only. An example of this phenomenon (Entelis et al., 1986), for polystyrene standards in a CHClJCC1, eluent, is given in Fig. 3 .By applying such conditions for a telechelic polymer, the resulting chromatogram will thus show the diversity of the number and nature of functional endgroups attached to the polymer backbones, i.e. the Functionality-type distribution-FTD (Entelis el al., 1986). This distribution, ideally two-dimensionally linked to the molecular weight distribution (MWD), is Exclusion Critical Adsorption IgM t 7.0 6.0 5.6 5.C 5.35 5.3 5.2 %CHC13 3.0) 2 .o 3.0 k.0 V,Id Figure 1. Transition from the exclusion to the adsorption separation mode through critical conditions for polystyrene standards (Entelis et a/., 1993). Column: LiChrosorb Si-100, 0.5 rnUmin; T, 27 "C; UV-275 nrn. / -I Figure 2. (a) Types of macromolecules (Skvortsov and Gorbunov, 1990) which can be studied by critical LC independent of the adsorbent's pore size (R>D or RD (17, macromolecular size; D, pore size).Dashed lines: polymer parts invisible at critical conditions.of key importance as it determines the overall reactivity and performance of a reactive polymer. Besides the determination of the functionality-type distribution, LC in the critical mode has also been applied to separate polymer blends (Pasch, 1993), to study AB and ABA block copolymers (Pasch et al., 1993; Pasch and Augenstein, 1993) to study branching or grafting (Gorschkov et al., 1988) to separate linear macromolecules from cyclic analogous (Entciis et al., 1986;Kruger et al., 1990) o r to separate block from random copolymers (Gorshkov et al., 1990). A pictural overview (Skvortsov and Gorbunov, 1990) of the different types of macromolecules which can be studied with critical LC is shown in Fig. 2. The dashed lines in the figures represent the polymer parts which are being made invisible by applying critical conditions for these

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Determination of functionality and molecular weight distributions in α‐hydroxy‐ω‐benzyloxyoligo(1,3,6‐trioxocane)s using HPLC methods

Cited by 13 publications

References 6 publications

MALDI-TOF mass spectrometry in the analysis of synthetic polymers

MALDI-TOF mass spectrometry in the analysis of synthetic polymers

Hyphenated Techniques in Liquid Chromatography of Polymers

Microcolumn liquid chromatography of macromolecules in the critical mode

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