DIN 55672-2:2016-03

The standard specifies the method and test conditions for determining the molar mass distribution and average molar mass values Mn (number average) and Mw (weight average) of polymers soluble in N,N-dimethylacetamide (DMAC) by gel permeation chromatography (GPC). Even though the chromatograms obtained show good repeatability, it is possible that this method cannot be used with certain polymer types because of specific interactions (such as adsorption) within the sample/eluent/column system. The method is not an absolute one and requires calibration with commercially available unbranched polymethyl methacrylate standards that have been characterized by independent absolute methods. The results for samples of polymers with different chemical structures are therefore only comparable within groups of samples of the same type. The specifications of this standard are not suitable for GPC analyses of polymer samples with Mw values greater than 106 g/mol and/or polymers with elution limits outside the calibration range (see 7.6 and Annex C). This document includes no correction methods (for example, for the elimination of peak broadening). If absolute molar mass values are required, an absolute method (for example, membrane osmometry for Mn or light scattering for Mw) shall be used. The standard DIN 55672-2 has been prepared by Working Group NA 002-00-02-03 AK "Gelpermeationschromatographie" ("Gel permeation chromatography") of Working Committee NA 002-00-02 AA "Lackrohstoffe" ("Raw materials for paints and varnishes") at DIN Standards Committee Coatings and Coating Materials (NAB).