Title: Molecular characterization
of polyamides 6, 11 and 12
Completion Date: 2004 - project
Step 1 - Comparison of SEC methods for characterization of polyamides
6, 11 and 12. The preferred method for this characterization uses
benzyl alcohol at 130 C as an eluent. Other methods are welcome:
HFIP or other solvents, after derivatization. This first step will
be conducted on samples of PA 6, PA 11 and PA 12, mainly commercial
samples, covering a wide range of molecular weights. It will allow
the comparison of different methods (experimental conditions, data
treatments...). The round robin test is restricted to three above
mentioned polyamides due to the lack of solubility of other common
polyamides (such as PA 6.6 and PA 6.12) in pure benzyl alcohol.
Step 2 - This second step will be dedicated to a deeper insight
into SEC method using benzyl alcohol with the objective to fix particular
parameters such as the nature of calibrants and the value of Mark-Houwink
constants used in the method. In this step, the same kind of work
as for benzyl alcohol will be done with another solvent (e.g. HFIP).
Also in this step, additional techniques will be used to assess,
true molecular weights: viscometry (off line or on line with SEC)
and light scattering. This is also an RRT project on commercially
important and difficult-to-measure materials. The first round has
been finished, and presently six participants have sent results.
The scatter of results is large but not as bad as initially anticipated.
Project completed - IUPAC Technical report published
76(11), 2009-2025, 2004
Last update: 11 November 2004