Polymer Characterization

Why should Polymer Characterization be important?

Are you interested to measure and determine the extent of the differences in the physical properties of a batch of polymer you receive from the previous batch?

Take two samples of polymer. They may both have the same chemistry (for instance, they may both be polyethylene), and yet may differ with one another in physical characteristics, such as in tensile strength, toughness, brittleness, melt viscosity, etc. These differences in physical characteristics are due to the difference in the distribution of molecular chain lengths. Each polymer sample will contain a distribution of molecules of different lengths, and it is the variation in the molecular weight distribution that account for their differences in physical characteristics.

This makes it important to measure the molecular weight distribution of polymers. Gel Permeation Chromatography/Size Exclusion Chromatography (GPC/SEC) is a reliable technique to characterize the molecular weight distribution of polymers. It is therefore a powerful and convenient analytical technique to help understand polymer performance.

Protein characterization

An essential part of the characterization of any protein is the determination of its molecular weight. Proteins can be separated according to their size and molecular weight, using Size Exclusion Chromatography (SEC). SEC with Multi-angle light scattering detector has increasingly become the technique that is used for the quantification of protein aggregation, the determination of protein conjugate stoichiometry and the confirmation of the oligomeric state of a protein.

Different Approaches in Analytical GPC/SEC

While recognizing that GPC/SEC is most effective method to measure molecular weight distribution of polymers, there is nonetheless a need to realize that there are a number of different approaches in GPC/SEC to do so, and these differences lie mainly in the detectors and calibration options:

  • Conventional GPC/SEC with a concentration detector (RI, UV, ELSD) and a narrow/broad/integral calibration curve constructed from matching molecular weight reference standards and materials.
  • GPC/SEC-light scattering with a concentration detector and a light scattering detector. If only a RALLS (right angle 90° laser light scattering) detector is available, in most cases a viscometer is needed to overcome the limitations of 90° light scattering (Triple detection approach).
  • GPC/SEC-viscometry with a concentration detector and a viscometer and a universal calibration curve constructed from any molecular weight reference standards and materials.

Complete turn-key solution

We offer complete turn-key systems for GPC/SEC with all detection methods:

  • Analytical GPC/SEC system with concentration detectors (RI, UV, ELSD), and/or Multi-angle Light-Scattering detectors, and/or Viscometer.
  • Semi-micro GPC/SEC. To save solvent and time semi-micro GPC/SEC using columns with a reduced inner diameter can be used. Semi-micro GPC/SEC instruments, with low dead volumes, have the advantage of saving on solvents as well as increased resolution.
  • Semi-preparative GPC/SEC. We offer a full turn-key semi-preparative system inclusive of an automated fraction collector and operated by WinGPC UniChrom GPC/SEC software, as well as a wide range of preparative columns for aqueous and organic solvents.
  • WinGPC Unichrom software solution to integrate all resources and to streamline laboratory processes:
  • from single instrument up to Client/Server solutions,

  • from one detector and conventional calibration up to multi-detection systems with advanced analysis methods.

  • GPC columns. We offer the widest range of column materials optimized for aqueous or organic solvents alike.
  • GPC standards. We offer a wide range of molecular weight GPC/SEC calibration standards, including certified standards that meet DIN, ASTM and ISO/EN 13885 requirements.
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