Certified Polymer Standards for Gel Permeation Chromatography

By: Rainer Walz, AnalytiX Volume 4 Article 3

We now offer a new dimension of polymer analysis: the first certified polymer standards. Polystyrene (broad and narrow), PEO and polylactic acid standards are available.

By Rainer Walz

Knowledge of the molecular structure of polymers, in- cluding chemical composition, branching, average chain length and chain length distribution, is critical to the manufacture of many commercial products, from plas- tic bottles to canopies of fighter jets. One analytical dif- ficulty facing polymer scientists is how to obtain poly- mer standards having a known chain length to calibrate the GPC analysis.

Because of the widespread need for certified polymer standards, and the impact of polymer quality on con- sumer safety, a government project was initiated. The polymer standards certifying process was coordinated by the German National Institute for Material Science and tested in Berlin by the Federal Institute for Materi- als Research and Testing (BAM). The certified parame- ters were carried out by well established round robin experiments done by several independent certified labo- ratories.

Researchers set out to provide polymer ana- lysts with reliable, certified polymer standards that meet the rigorous requirements of the BAM tests. These standards are characterized using a battery of analytical tests, including GPC, GPC with light scatter- ing detection (on-line and off-line) and GPC-viscometry (on-line and off-line). To further characterize our poly- mer standards, we also use MALDI-TOF, NMR, DSC and rheological testing when appropriate.

The data provided by this extensive Quality Assurance testing appears in the Certificate of Analysis for each lot of polymer standards. Some critical results presented in the Certificate of Analysis include the aver- age molecular weight (Mw and Mn), polydispersity (D) and other information about the dimension of poly- mer solutions like intrinsic viscosity (h).

Certified Polymer Standards can be used for calibration of the following analytical instruments: GPC, light scattering, viscometry, rheology, MALDI-TOF, spectroscopy, surface analysis.

 


Figure ......... Gel permeation chromatography

 

They offer the benefits of:

  • Well established and standardized characterization using different, independent analytical methods
  • Round robin experiments that guarantee reliable parameters like Mw and Mn
  • High accuracy
  • Extensive quality documentation

 

The Certified Polymer Standards are supplied in 100 mg quantities, in glass vessels packed in aluminium bags to protect them from air and moisture. The lot-depen- dent average molecular weight is printed on the label.

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