Novel Polyimide Architectures: Towards Membranes with

Tunable Transport Properties

PhD Candidate: Zeljka MadzarevicDepartment: ASMSection: Novel Aerospace MaterialsSupervisor: Theo DingemansPromoter: Theo DingemansStart date: 01-10-2011Funding: DPICooperations: MST group, UTwente

Aero

space

En

gin

eeri

ng

[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).

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.

The mixed gas permeation

behaviour of P1-ODPA II membrane, using 50/50 CO2/CH4 feed composition at

40 bar

GPC results:Average Molecular Weight Table

Thermal analysis results:DSC and TGA

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

O O

O

OO

O

O

O

O

O

O

O

O

O

O

O

O

O

O

OOH2N NH2

OOH2N NH2

O ON

O

O

O

N

O

On

para

ortho

meta

P1M1

O1

PMDA

BTDA

ODPA

BPDA

Selectivity of P1 based membranes

𝛼= 𝑌𝐶𝑂2/𝑌𝐶𝐻4𝑋𝐶𝑂2/𝑋𝐶𝐻4

Solution-diffusionmechanism

Feed

Permeate

Retentate

CO2 Permeability of P1 based membranes

N Ar

O O

N R

OO n

a 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. d Degradation temperature.e Tg is not visible in the DSC scan, to be determined by DMTA.

PolymerMn

a Mwa PDI=Mw/Mn

P1-ODPA 52,930 98,619 1.86

P1-BPDA 102,261 191,369 1.87

P1-BTDA 108,700 211,700 1.95

P1-PMDA 108,500 154,500 1.43

M1-ODPA 63,100 151,500 2.40

M1-BPDA 58,700 153,400 2.62

M1-BTDA 86,900 168,800 1.94

M1-PMDA 69,300 174,100 2.51

O1-ODPA 29,900 53,900 1.81

O1-BPDA 27,800 83,200 2.99

O1-BTDA 41,700 91,000 2.18

O1-PMDA 45,800 148,007 3.24

Polymer Tg (oC)b Tm(oC)c 5% weight loss (oC)d

P1-ODPA 247.6   514.8

P1-BPDA 271.6 457.2 535.7

P1-BTDA 285.7   508.9

P1-PMDA -e   533.4

M1-ODPA 220.7   529.5

M1-BPDA 231.9 393.7 536.7

M1-BTDA 237.7 341.8 510.5

M1-PMDA -e 539.8

O1-ODPA 216.7   500.6

O1-BPDA 247.8   538.8

O1-BTDA 238.8   529.4

O1-PMDA -e   509.3