scholarly journals Separation of Poly(styrene-block-t-butyl methacrylate) Copolymers by Various Liquid Chromatography Techniques

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Tina Šmigovec Ljubič ◽  
David Pahovnik ◽  
Majda Žigon ◽  
Ema Žagar
Keyword(s):  
Liquid Chromatography ◽  
Block Copolymers ◽  
Molar Mass ◽  
Small Difference ◽  
Reversed Phase ◽  
Butyl Methacrylate ◽  
Critical Conditions ◽  
Chromatographic Techniques ◽  
Methacrylate Copolymers ◽  
Gradient Liquid Chromatography

The separation of a mixture of three poly(styrene-block-t-butyl methacrylate) copolymers (PS-b-PtBMA), consisting of polystyrene (PS) blocks of similar length andt-butyl methacrylate (PtBMA) blocks of different lengths, was performed using various chromatographic techniques, that is, a gradient liquid chromatography on reversed-phase (C18 and C8) and normal-phase columns, a liquid chromatography under critical conditions for polystyrene as well as a fully automated two-dimensional liquid chromatography that separates block copolymers by chemical composition in the first dimension and by molar mass in the second dimension. The results show that a partial separation of the mixture of PS-b-PtBMA copolymers can be achieved only by gradient liquid chromatography on reversed-phase columns. The coelution of the two block copolymers is ascribed to a much shorter PtBMA block length, compared to the PS block, as well as a small difference in the length of the PtBMA block in two of these copolymers, which was confirmed by SEC-MALS and NMR spectroscopy.

Limited sample recovery in coupled methods of high-performance liquid chromatography of synthetic polymers

2006 ◽  
Vol 60 (3) ◽  
Author(s):  
D. Berek ◽  
A. Russ
Keyword(s):  
Liquid Chromatography ◽  
High Performance ◽  
Retention Mechanism ◽  
Model Systems ◽  
Critical Conditions ◽  
Chromatographic Methods ◽  
Enthalpic Interaction ◽  
Sample Recovery ◽  
Gradient Liquid Chromatography ◽  
Liquid Chromatographic

AbstractComplex polymer systems, which exhibit multiple distributions in their molecular parameters can be characterized by coupled liquid chromatographic methods. The latter combine entropic (exclusion) and enthalpic (interaction) retention mechanisms. However, recent experimental results suggest that some coupled liquid chromatographic methods may suffer from incomplete sample recovery. This refers, for example, to liquid chromatography under critical conditions of enthalpic interactions and to eluent gradient liquid chromatography. Sample recovery in both latter methods was investigated for selected model systems applying adsorption retention mechanism. Reduced sample recovery was confirmed for both methods. It was revealed that even very high final strength of mobile phase may be insufficient for complete elution of polymer samples in eluent gradient polymer liquid chromatography.

scholarly journals Temperature Gradient Interaction Chromatography: A Perspective

2021 ◽  
Author(s):  
Lian R. Hutchings ◽  
Antonella Pagliarulo
Keyword(s):  
Liquid Chromatography ◽  
Temperature Gradient ◽  
Molar Mass ◽  
Reversed Phase ◽  
Normal Phase ◽  
Branched Polymers ◽  
Size Exclusion ◽  
Advanced Technique ◽  
High Molar Mass ◽  
Exclusion Chromatography

AbstractThe application of temperature gradient interaction chromatography (TGIC) as an advanced technique for the characterisation of polymers is discussed, in comparison to other liquid chromatography techniques and in particular the ubiquitous size exclusion chromatography. Specifically, the use of reversed-phase TGIC for the interrogation of complex branched polymers and normal-phase TGIC for characterisation of high-molar mass end-functionalised polymers is highlighted.

Sign in / Sign up

Export Citation Format

Share Document