Researchers from Synpo selected Wyatt's instrumentation over a host of competing equipment to study the characterisation of molar mass distribution of synthetic and natural polymers
Synpo is a research institute for synthetic resins and coatings and the Institute of Polymeric Materials, University of Pardubice, Czech Republic.
The researchers combined Wyatt Technology's Eclipse - a state-of-the-art separation system - with the Dawn Mals photometer, to generate a powerful and versatile A4F (asymmetric flow field fractionation) tool for polymer analysis and characterization.
There is a burgeoning interest in the development of powerful and convenient separation techniques.
A4F is one type of field flow fractionation (FFF) separation technique.
Unlike size exclusion chromatography (SEC) where the development of instrumentation has been driven by other liquid chromatographic techniques, commercially available and reliable FFF instruments were, until recently, largely unavailable.
Knowledge of the properties of polymers, and polymeric systems, is of fundamental importance in the pharmaceutical sciences and the new generation of A4F instruments bring new possibilities for the separation of various polymers, proteins and particles with several advantages over traditionally employed SEC.
For this application, an A4F-Mals instrumental set-up consisting of the Wyatt Eclipse and a Wyatt Dawn photometer was compared with a Sec-Mals set-up composed of a Wyatt Minidawn.
Tetrahydrofuran (THF) was used as the mobile phase for both SEC and A4F experiments, at SEC flow rate and A4F channel flow rate of 1ml/min.
Samples were injected as solutions in THF (for polymers typically 100ul of about 0.2%w/v).
Results demonstrated the ability of A4F to provide a polymer separation quite comparable with SEC.
The cumulative molar mass distribution plots obtained by the two techniques almost overlay, which proves identical separation efficiency of A4F and SEC.
The possible advantages of A4F over SEC include a broad separation range accessible by a single channel, the elimination of polymer interactions with column packing and the efficient separation of branched polymers.
A further important feature of A4F is the ability to separate macromolecules over a very broad range of molar masses without the need to change separation conditions.
Additionaly, various nanoparticles have achieved great popularity among material chemists, as materials with great potential to enhance various polymer properties.
The size distribution of nanoparticles can be determined by A4F-MALS.
This application demonstrates that the A4F-MALS combined technique can serve as a routine method of polymer analysis and characterization.
A4F provides separation efficiency entirely comparable with traditional dominating SEC methods.
In addition, it yields superior separation of branched polymers, polymers containing ultra high molar mass fractions up to at least 108g/mol, and nanoparticles.
