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Novel Polyimide Architectures:
Towards Membranes with
Tunable Transport Properties
PhD Candidate: Zeljka Madzarevic
Department: ASM
Section: Novel Aerospace Materials
Supervisor: Theo Dingemans
Promoter: Theo Dingemans
Start date: 01-10-2011
Funding: DPI
Cooperations: MST group, UTwente
Membrane technology has proven to be a highly energy efficient technology for the separation of CO2 form natural gas in industrial applications.
Polyimides are attractive materials for gas separation owing to their excellent gas separation (high selectivity for gas pairs such as CO2/CH4) and
physical properties, such as high thermal stability, high chemical resistance, and mechanical strength. [1]
Polyetherimide (PEI) films with ODPA dianhydride moiety (P1-ODPA) have shown high selectivities in experiments at elevated pressures with a
50/50% CO2/CH4 feed gas mixture.[3] Therefore a series of PEIs with slightly different moieties has been designed to be tested and compared to give
more information on the effects of molecular structure on their gas separation properties.
meta
para
Solution-diffusion
mechanism
Feed
PMDA
ODPA
M1
P1
Retentate
ortho
This is a homologous series, which will enable us to
investigate the role of polymer backbone composition
on gas transport behaviour The poly(amic acid)s were
prepared from dianhydride and diamine monomers in NMP
(10 or 15 wt.% solids) at room temperature,
filtered and thermally imidized
BTDA
O1
BPDA
Aerospace Engineering
GPC results:
Average Molecular Weight Table
Permeate
Thermal analysis results:
DSC and TGA
Polymer
Mna
Mwa
PDI=Mw/Mn
Polymer
Tg (oC)b
P1-ODPA
52,930
98,619
1.86
P1-ODPA
247.6
P1-BPDA
102,261
191,369
1.87
P1-BPDA
271.6
P1-BTDA
108,700
211,700
1.95
P1-BTDA
285.7
508.9
P1-PMDA
108,500
154,500
1.43
P1-PMDA
-e
533.4
M1-ODPA
63,100
151,500
2.40
M1-ODPA
220.7
529.5
M1-BPDA
58,700
153,400
2.62
M1-BPDA
231.9
393.7
536.7
M1-BTDA
86,900
168,800
1.94
M1-BTDA
237.7
341.8
510.5
M1-PMDA
69,300
174,100
2.51
M1-PMDA
-e
539.8
O1-ODPA
29,900
53,900
1.81
O1-ODPA
216.7
500.6
O1-BPDA
27,800
83,200
2.99
O1-BPDA
247.8
538.8
O1-BTDA
41,700
91,000
2.18
O1-BTDA
238.8
529.4
O1-PMDA
45,800
148,007
3.24
O1-PMDA
-e
509.3
Tm(oC)c
5% weight loss (oC)d
514.8
457.2
535.7
Compared to a polystyrene standard. b Tg is reported at the inflection point, by DSC (second heat). c Tm is reported as the peak temperature.
temperature.
e T is not visible in the DSC scan, to be determined by DMTA.
g
a
CO2 Permeability of P1 based membranes
d
The mixed gas
permeation behaviour
of P1-ODPA II
membrane, using
50/50 CO2/CH4 feed
composition at 40 bar
Degradation
Selectivity of P1 based membranes
2 /4
=
2 /4
[1] Cecopierigomez, M. et al. On the limits of gas separation in CO2/CH4, N2/CH4 and CO2/N2 binary mixtures using polyimide membranes. Journal of Membrane Science 293, 53-65 (2007).
[2] Xiao, Y.T. et al. The strategies of molecular architecture and modification of polyimide-based membranes for CO2 removal from natural gas — A review. Progress in Polymer Science 34, 561-580 (2009).
[3] Simons, K. et al. CO2 sorption and transport behavior of ODPA-based polyetherimide polymer films. Polymer 51, 3907-3917 (2010).

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