Thesis presented in partial fulfillment of the requirements for
the degree of Master of Technology (MTech)
at
Department of Chemistry, Faculty of Applied Science,
Cape Peninsula University of Technology
2011 / Aromatic polyamides (PAs) are widely used as high-performance polymers in technical
applications due to their unique combination of outstanding thermal, optical, mechanical
and chemical properties. Although PAs are mostly utilized where strength or heat
resistance is of primary concern, they also find use in other important applications such
as in NOMEX membranes for desalination of brackish water or seawater.
PAs do however have some disadvantages such as high melting points, high glass
transition temperatures (T 9) and a limited solubility in most organic solvents, wh.ich
makes their processing difficult. Polyureas (PUs) are generally known for their excellent
thermal stability and high chemical resistance due to the presence of thermally stable
bonds of aromatic or heterocyclic ring systems along their backbone.
Both polymer systems are poorly researched when it comes*' the introduction of furan
units into the chains. The same is valid for cases where two or more different diacids or
diamines are incorporated. The aim of this study was therefore to investigate the
influence of furan units in the polymer chains and the change in properties if the
composition of starting materials is varied further.
Nineteen PAs were prepared via the interfacial polymerization method and the
homogeneous phase polymerization method. These polymers were prepared either with
furan- or isophthalic acids in their chains and then compared with the copolymers,
containing both diacids in different ratios. Products were characterized by various
analytical techniques.
Furanoyl-2,5-dichloride (FDC) and different amounts of isophthaloyl chloride (IPDC)
- 0, 10, 30 and 50% - as the basic starting monomers were reacted individually with four
diamines: m-phenylen diamine (MPD), 4,4'-diamino diphenylsulfone (DDS), 4,4'-diamino
diphenylether (ODE) and 2,4-bis(4-aminophenyl)-6-phenyl-1,3,5-triazine-2,4,6-triamine
(BAT) by interfacial or homogeneous polycondensation reactions.
Two polyureas, starting with furanoyl-2,5-diazide (FDZ) and transformed into the
diisocyanate were prepared by reaction with two diamines, namely MPD and DDS in
homogeneous solution.
The PAs and PUs were characterized by Fourier-Transform Infrared Spectroscopy
(FTIR), Proton NMR CH), Carbon NMR C3C), Gel Permeation Chromatography (GPC),
Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC).
The water up-take per polymer unit (mol water I repeat unit of the polymer) was
measured. The values for 70% Relative Humidity (RH) were between 0.87 and 1 ~80
moles of water per repeat unit and for 43% RH between 0.40 and 1.35 mols.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:cput/oai:localhost:20.500.11838/736 |
| Date | January 2011 |
| Creators | Rashwan, Osama |
| Contributors | Hugo, V., Prof, Weber, W.G., Dr |
| Publisher | Cape Peninsula University of Technology |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Rights | http://creativecommons.org/licenses/by-nc-sa/3.0/za/ |
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