Molar-mass dispersity, ÐM
A measure of the distribution of molecular mass, relative molecular mass, or molecular weight of polymer. This is a new term proposed by IUPAC in 2009 to replace the term "polydispersity" or "polydispersity index". "Ð" is pronounced “D-stroke” to minimize confusion over "D", the diffusion coefficient.
Molar-mass dispersity calculation
ÐM = Mw / Mn
- Mw = mass-average molecular weight
- Mn = number-average molecular weight