1. Solvent Sorption and Ethylenediamine Cross-Linking of Matrimid Films
This material is based upon work supported and funded by the
Department of Chemical Engineering at Kansas State University.
Lauren McDonald, John Stanford, and Mary Rezac
Kansas State University – Department of Chemical Engineering
Introduction
References and Acknowledgements
Cross-Linking Technique
Results and Conclusions
Motivation
Liquid Sorption in Matrimid
Cross-Linking
Time (min) Initial Mass of
Filter (mg)
Final Mass
of Filter
(mg)
Percent Mass
Left (mg)
30 2763 2765 1.7
30 2764 2766 1.4
30 2763 2765 1.8
60 2760 2771 5.3
60 2755 2764 4.1
60 2756 2764 8.2
• This research involves investigating a non-traditional
approach for chemically cross-linking Matrimid
membranes and films
• Membranes used are cast from a 16 wt% solution of
Matrimid in tetrahydrofuran, gamma-butyrolactone, and
butanol
• Films are made from Matrimid and dichloromethane at
a 2wt% solution
• The 2wt% solution is cast into metal O rings on a glass
plate and covered until the solution dries into a film
• After the films are carefully removed, they are put into the
vacuum oven until they are ready to cross link
• The purpose of the approach is to increase chemical
stability of the dense top-layer surface without
adversely affecting the porous substructure of the
Matrimid membranes
• Beginning studies to determine the extent of cross-
linking, changes in surface properties, and extent of
added chemical resistance
• EDA vapor only comes in contact with dense surface
layer of membrane
• Using EDA as opposed to other diamines allows the
avoidance of diamine solvents (methanol), which
commonly swell Matrimid
• The longer cross-linking time builds chemical resistance on
the membrane
• Because of the added chemical resistance, the 60 minute
cross-linked membranes can be used to resist harsher
environments as opposed to 30 minute cross-linked film
• The liquid sorption shows that solvents like DMF and
furfuryl alcohol swell the membranes too much, as
opposed to the alcohols
Liquid Sorption
Mass Uptake
gsolute/gpolymer
Mass Uptake
gsolute/gpolymer
Mass Uptake
gsolute/gpolymer
• Took initial mass of each film and submerged them in
jars of their respective solvent
• Over time (approximately every week), took the film
out of solvent, quickly patted it dry, and reweighed it
• Took measurements until the mass evened out (no
more mass uptake)