SCIENCE|natural and applied sciences|physical sciences|chemistry
- meán uimhríochtúil an mheáchain mhóilínigh Tagairt Faomhadh an téarma seo mar chuid de Thionscadal Lex
- ga
- Zahlenmittel der Molmasse | Zahlenmittel | Zahlendurchschnitt | Mn
- de
- Sainmhíniú Molekulargewichtsmittelwert fuer Hochpolymere, der mit Hilfe physikalischer Methoden in Verbindung mit isothermischer Destillation und Endgruppenanalyse ermitteit wird Tagairt Fromherz-King
- number-average molecular weight
- en
- Sainmhíniú a way of determining the molecular weight of a polymer. Polymer molecules, even ones of the same type, come in different sizes (chain lengths, for linear polymers), so the average molecular weight will depend on the method of averaging. The number average molecular weight is the ordinary arithmetic mean or average of the molecular weights of the individual macromolecules. Tagairt "Wikipedia http://en.wikipedia.org/wiki/Molar_mass_distribution [19.1.2010]"
- Nóta It is determined by measuring the molecular weight of n polymer molecules, summing the weights, and dividing by n. Mn = ΣNiMi/ΣNi or Mn=Σni=1HiΣni=1Hi/Mi where Hi is the level of the detector signal from the baseline for the retention volume Vi,Mi is the molecular weight of the polymer fraction at the retention volume Vi, andn is the number of data points.