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.  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. 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  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).  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).  Simons, K. et al. CO2 sorption and transport behavior of ODPA-based polyetherimide polymer films. Polymer 51, 3907-3917 (2010).