The certification of a polyethylene standard reference material, SRM 2887, is described. The Mw of SRM 2887 by light scattering was determined to be 196.4x10+3 g/mol with a sample standard deviation of 6.7 x10+3 g/mol. A combined expanded uncertainty for this light scattering Mw determination, including systematic and random uncertainties, was estimated to be 13.4 x10+3 g/mol. The limiting viscosity number of SRM 2887, by solution viscosity, in 1,2 4-trichlorobenzene was determined to be 273.5 mL/g with a sample standard deviation of 3.7 mL/g. The standard deviation on the mean value was 0.4 mL/g. A combined expanded uncertainty for this limiting viscosity number determination was 4.0 mL/g. The bottle-to-bottle variation of the SRM was check by size exclusion chromatography (SEC) and found to be negligible.
Citation: NIST Interagency/Internal Report (NISTIR) - 6456Report 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