The certification of a polyethylene standard reference material, SRM 2885, is described. The Mw of SRM 2885 by light scattering was determined to be 6.28 x 10+3 g/mol with a sample standard deviation of 0.39 x 10+3 g/mol. A combined expanded uncertainty for this light scattering Mw determination, including systematic and random uncertainties, was estimated to be 0.57 x 10+3 g/mol. The limiting viscosity number of SRM 2885, by solution viscosity, in 1,2,4-trichlorobenzene was determined to be 24.6 mL/g with a sample standard deviation of 0.45 mL/g. The expanded uncertainty on the mean value was 0.45 mL/g. A combined expanded uncertainty for this limiting viscosity number determination, including systematic and random uncertainties, was 0.48 mL/g. The bottle-to-bottle variation of the SRM was checked by size exclusion chromatography (SEC) and found to be negligible.
Citation: NIST Interagency/Internal Report (NISTIR) - 6454Report Number:
NIST Pub Series: NIST Interagency/Internal Report (NISTIR)
Pub Type: NIST Pubs
certification, limiting viscosity number, molecular mass, narrow fraction, polydispersity index, polyethylene, standard reference material