The MW (g/mol) of Poly(methylmethacrylate) (PMMA) for artificial tooth was
calculated by Zimm plot method (batch) and GPC/MALS and the results were compared
between the two.
The Zimm plot method is to calculate the average absolute molar mass directly,
without any separation. On the other hand, GPC/MALS is the method to make
a size exclusion first then detect the absolute molecular weights and calculate
the average.
As a result, both values are almost the same. Zimm plot method can calculate
the second virial coefficient, but it can’t measure the molecular weight
distribution. However, combining these two methods can acquire more information
and facilitate the characterization of high polymer in a steadier way. 2mL
sample loop was used for the Zimm plot analysis and the plateau was measured
by flow injection. This method has less noise and enables the Zimm plot measurement
in a good reproducibility in approximately 30 minutes.
Method Mw(g/mol) RMS radius(nm) second virial coefficient (mol mL/g2)
Zimm Plot 3.679e+5 31.3 4.019e-4
GPC/MALS 3.526e+5 30.4 -
(Zimm plot) (GPC/MALS)
Concentration : 0.09%~0.41% 0.230%
Column : No column Shodex GPC KF-806L (8.0mmID*300mm)
Eluent : THF THF
Flow rate : 1.0 mL/min 1.0mL/min
Injection Vol. : 2mL 100µL
Detector : MALS MALS + Shodex RI
