M0726(2):LMFI Series 5000 Lab Melt Flow Indexer
27
English 02/2014
Any inaccuracies in the melt density will be propagated proportionally along to the MFR
values. Thus a 1% error in the melt density means a 1% accuracy error in the MFR the
value.
Calculating PET Intrinsic Viscosity (I.V.) from the Melt Indexer
This feature allows the Melt Indexer to correlate Melt Flow Rate (g/10 min.) to Intrinsic Viscosity
(dl/g). Intrinsic Viscosity (IV, ASTM D3835) is a "wet chemistry" technique used to assess the
specific volume of an isolated polymer chain, when dissolved in a good solvent. This value is
directly related to the molecular weight of the polymer. Melt viscosity or MFI measurement is
another, empirical (non-absolute like I.V.), way to assess molecular weight. Melt Viscosity and
Intrinsic Viscosity are related in such a way that IV can be directly calculated from Melt Index
values. This is described in greater detail in the applications brief, "Correlating Melt Rheology of
PET to Solution Intrinsic Viscosity" by J. Reilly and P. Limbach, available from DYNISCO
POLYMER TEST on request
.
MFR
Melt Flow vs.
IV PET Homopolymer
1000
100
10
(g/10min)
1
.30
.40
.50
.60
.70
.80
.90
1.00
1.10
I.V. (dl/g) (OCP 25C)
