Polydimethylsiloxane and poly(ethylene oxide) randomly grafted polyamide (PA-g-SE) and poly(amide-imide) (PAI-g-SE) were prepared by a macromonomer method, and the effect of the backbone structure on the thermal property and the solubility of the graft copolymers was investigated. Glass transition temperature (Tg) of PAI-g-SE was observed in the range of 160 -170°C, whereas Tg of PA-g-SE was not observed in the range of 0 -300°C. The obtained PAI-g-SE was soluble in some solvents such as DMSO, DMF, THF and chloroform, whereas PA-g-SE was soluble only in NMP just after precipitation when it was swollen in methanol. In addition, the solubility of PAI-g-SE was depended on the components, where the affinity of polymer against THF and chloroform increased with the increase of PDMS content in the polymer.

Polydimethylsiloxane (PDMS) grafted polyimides with different backbone structures were prepared by polycondensation of 3,5-bis(4-aminophenoxy)benzyloxypropyl-terminated PDMS with 4,4'-oxydiphtalic dianhydride (ODPA) and 4,4'-hexafluoroisopropylidene diphthalic anhydride (6FDA) followed by chemical imidization to afford PI-g-PDMS and FPI-g-PDMS, respectively. Another PDMS-grafted polyimide, MPI-g-PDMS, was also prepared by similar procedure from 3,5-bis(4-amino-3-methylphenoxy)benzyloxypropyl-terminated PDMS and ODPA.1 H-NMR and FT-IR spectra clearly demonstrated that the desired PDMS-grafted polyimides were successfully synthesized. FPI-g-PDMS and MPI-g-PDMS exhibited the high solubility, which were soluble in chloroform, THF, DMF, NMP, toluene, benzene as well as acetone, while PI-g-PDMS was soluble only in chloroform. Therefore, the membranes could be prepared by solvent-casting method using chloroform. Interestingly, the obtained membranes became insoluble in any solvents after the thermal imidization at 200℃ in vacuo for 24 h.

Poly(ethylene oxide) graft copolyamides (PA-g-PEO and PA-g-PEOC) were prepared by a macromonomer method, and the effect of the PEO segment lengths or the polar end group of the graft copolymers on the CO 2 permselectivity was investigated. In addition, poly(ethylene oxide) and polydimethylsiloxane randomly graft copolyamide (PA-g-SEr) were prepared by a macromonomer method, and the effect of copolymer composition on the gas permeability was also investigated. The obtained polymers were soluble in aprotic polar solvents, such as DMF, NMP and DMSO. Then, the tough and flexible membranes could be prepared by solvent-casting method using NMP as solvent. The CO 2 permselectivity of the polymer membranes was evaluated. The CO 2 permeability coefficient of PA-g-PEO membrane containing the longer PEO segment was 32.6 Barrer, and the selectivity of CO 2 /N 2 was nearly 50. It was also found that the moderate introduction of polydimethylsiloxane side chain was effective to increase the CO 2 permeability coefficient to 39.2 Barrer while maintaining the selectivity of CO 2 /N 2. On the other hand, the introduction of the polar diethylcarbamoyl group into PEO chain end caused the decrease of the CO 2 permeability coefficient to 5.96 Barrer.