Examination of the Universality of the Calibration Curve of Size Exclusion Chromatography by Using Polymers Having Complex Macromolecular Architectures

Stogiou, Maria; Kapetanaki, Cleopatra; Iatrou, Hermis

doi:10.1080/10236660213162

Cited by 11 publications

(6 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In 1979, Roovers found that polystyrene linear and model comb polymers obey [η] M -based universal calibration but did not discuss the issue of R g . Similarly in 2002, Stogiou et al showed that μ-stars, H-shaped, π-shaped, and linear tetrablock copolymers obey [η] M -based universal calibration, but they also did not discuss R g . On the other hand, Chance et al showed in 1995 that the [η] M correlation fails for low molecular weight linear polymers of different species .…”

Section: Introductionmentioning

confidence: 99%

A Study of the Separation Principle in Size Exclusion Chromatography

et al. 2004

View full text Add to dashboard Cite

Size exclusion chromatography (SEC) separates polymer molecules according to their size in dilute solution, but what size to use has been a matter of debate for 35 years. In 1967, Benoit and co-workers found an excellent correlation between elution volume and a dynamically based molecular size, the hydrodynamic volume V H, for a wide range of species and large-scale molecular architectures. However, both theory and simulations assume a thermodynamic separation principle. This assumption is based on experimental observations that elution volumes are independent of flow rates. Thus, one might surmise that the radius of gyration R g is a more appropriate size measure for purposes of universal SEC calibration, although the calculations of Casassa and co-workers on star polymers suggest some other thermodynamically based size may be required. In an attempt to resolve this dilemma, we undertook an extensive study of SEC with three groups of nearly monodisperse polymerslinear polystyrenes, linear polyethylenes, and polyethylenes with several types of long chain branching. Measurements of R g, molecular weight M, intrinsic viscosity [η] (V H = [η]M), and the elution volume on these various samples demonstrate that R g correlates the partitioning of linear chains more satisfactorily than does V H, while the reverse is true for branched chains. Extending the theoretical calculations of distribution coefficients for star polymers to other types of branched architectures may be necessary to settle the matter.

show abstract

Section: Introductionmentioning

confidence: 99%

A Study of the Separation Principle in Size Exclusion Chromatography

et al. 2004

View full text Add to dashboard Cite

show abstract

“…Although Φ is mostly treated as a constant, in reality its value can vary almost by ± 100%. These facts question the universality of the UC and indicate why for some polymers the UC concept may apply whereas to some others it does not 8, 9. For statistically branched polymers, such as those characterized in the present study, the molecular weight, the degree of branching and the breadth of the molecular weight distribution increase with conversion.…”

Section: Introductionmentioning

confidence: 57%

Number‐average molecular weight of branched polymers from SEC with viscosity detection and universal calibration

Netopilı́k¹,

Podešva²,

Lokaj³

et al. 2008

Polymer International

View full text Add to dashboard Cite

BACKGROUND: Number-average molecular weight, M n , is an important characteristic of synthetic polymers. One of the very few promising methods for its determination is size-exclusion chromatography (SEC) using on-line viscometric detection and assuming the validity of the universal calibration concept. RESULTS:We have examined the applicability of this approach to the characterization of statistically branched polymers using 22 copolymers of styrene and divinylbenzene as well as 3 homopolymers of divinylbenzene with various degrees of branching. SEC with three on-line detectors, i.e. concentration, light scattering and viscosity, enables us to evaluate experimental data by various computational procedures yielding M n and weight-average molecular weight, M w . Analysis of the results has shown that the universal calibration theorem has limited validity, apparently due to the dependence of the Flory viscosity function on the molecular shape, the molecular weight distribution and the expansion of molecules. CONCLUSION: For complex polymers, the universal calibration, i.e. the dependence of the product of intrinsic viscosity and molecular weight, [η]M, on elution volume, can differ in values of [η]M from those obtained for narrow molecular weight standards by 10-15%. The method studied is helpful for the determination of M n of polymers, in particular of those with very broad molecular weight distribution, such as statistically highly branched polymers.

show abstract

“…UC is based on the fact that V H ∝ [η]M, where [η] is the intrinsic viscosity, for a wide range of polymers and complex architectures including, for example, dendritic, H, star, comb, and copolymers 14–16. This versatility makes UC a useful tool for measuring molecular weight because neither the architecture nor chemical composition of the analyzed compounds have an effect on the result.…”

Section: Resultsmentioning

confidence: 99%

Synthesis and characterization of 2,2‐bis(methylol)propionic acid dendrimers with different cores and terminal groups

Malkoch

Claesson

Löwenhielm

et al. 2004

J. Polym. Sci. A Polym. Chem.

View full text Add to dashboard Cite

Three sets of aliphatic polyester dendrimers based on 2,2-bis(methylol)propionic acid (bis-MPA) were synthesized. Two of the sets had benzylidene terminal groups and either a trimethylolpropane or triphenolic core moiety. The last set had acetonide terminal groups and a triphenolic core moiety. Benzylidene-[G#1]-anhydride and acetonide-[G#1]-anhydride were used as the reactive building blocks in the construction of all dendrimers. The large excess of building blocks used in the coupling reactions initially resulted in considerable material loss. This waste was eliminated through the development of a recycling method. 1 H and 13 C NMR and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) analysis were used to verify the purity of all compounds. Size exclusion chromatography (SEC) was used, as well as MALDI-TOF, for molecular weight determinations. The SEC measurements were conducted with a universal calibration method and an online right-angle laser light scattering detector. Measured dendrimer molecular weights were close to their theoretical molar masses. Observations were also made of the hydrodynamic radius and intrinsic viscosity for the different dendrimers.

show abstract

Examination of the Universality of the Calibration Curve of Size Exclusion Chromatography by Using Polymers Having Complex Macromolecular Architectures

Cited by 11 publications

References 14 publications

A Study of the Separation Principle in Size Exclusion Chromatography

A Study of the Separation Principle in Size Exclusion Chromatography

Number‐average molecular weight of branched polymers from SEC with viscosity detection and universal calibration

Synthesis and characterization of 2,2‐bis(methylol)propionic acid dendrimers with different cores and terminal groups

Contact Info

Product

Resources

About