Sage-Tips

What is GPC in polymer chemistry?

Gel permeation chromatography (GPC) is a type of size-exclusion chromatography (SEC), that separates analytes on the basis of size, typically in organic solvents. The technique is often used for the analysis of polymers.

What is the principle of GPC?

GPC is based on separation by molecular size rather than chemical properties. It employs the principle of size-exclusion chromatography (often referred to as SEC) to separate samples of polydisperse polymers into fractions of narrower-molecular-weight distribution.

What is the difference between GPC and HPLC?

The only really relevant difference are the columns and the detectors. For HPLC, UV-Vis detectors are THE standard, for GPC/SEC differential refractive index detector are THE standard. For GPC/SEC viscosimetry and/or light scattering makes sense, too, depending on your analyte also UV-Vis.

Why is DN DC important in multi detector GPC?

Why is dn/dc important? As hinted at earlier, when analyzing samples using a GPC/SEC system with advanced detectors knowing the exact concentration of the sample at each data slice is critical. Ultimately, the dn/dc value is important because it is the link that translates the raw RI signal to sample concentration.

Is gel filtration chromatography sensitive?

The technique is sufficiently sensitive to be influenced by nonpolar groups normally buried within the tertiary structure of the protein, but which are exposed if the peptide chain is incorrectly folded or damaged. This sensitivity is useful for separating the native protein from other forms.

What is the importance of determination of molecular weights of polymers?

The molecular weight of a polymer is directly related to its properties. As the molecular weight increases, mechanical properties generally increase. Every polymer has an ideal molecular weight at which the balance of different properties (such as processability, strength, brittleness etc.) is optimized.

Is GPC quantitative?

Common methods are so-called GPC or size-exclusion chromatography (SEC), but these are not fully applicable to provide generally valid quantitative data.

Is GPC and SEC the same?

GPC, GFC, and SEC are names interchangeably used to describe the same liquid column chromatographic technique. SEC is the most descriptive term and should thus be preferred.

How is DN dc value calculated?

The dn/dc is determined from the slope, which reflects the detector constant multiplied by the dn/dc. For this approach typical RI detectors are very often used independent of the detector light source type.

Why is GPC such an important technique to the polymer chemist?

Controlling the kinetics of the polymerization is extremely important in obtaining a desired molecular weight distribution.That is why GPC is such an important technique to the polymer chemist. Here we show an an overlay of two molecular weight distributions of a polymer (in this case polystyrene):

What is gel permeation chromatography (GPC)?

Gel permeation chromatography (GPC) is one of the most powerful and versatile analytical techniques available for understanding and predicting polymer performance. It is the most convenient technique for characterizing the complete molecular weight distribution of a polymer.

What is the advantage of GPC over other methods?

The preference for GPC is because of its relatively low cost, simplicity, and ability to provide accurate, reliable information about the molecular-weight distribution of a polymer. GPC is based on separation by molecular size rather than chemical properties.

What is the basis for the design of the GPC?

GPC is based on the behaviour of polymer molecules in solution In the solid state polymers can be considered like spaghetti – a confusing mass of intertwined chains In solution, polymer molecules are discrete entities Due to entropic effects all but the most rigid of polymer chains curls up in solution to form a ball like shape