Carboxylated poly(phenylene oxide) was synthesized by organometallic reaction. The presence of carboxyl group was verified by FT-IR spectrum showing the characteristic carbonyl stretching peak at $1720cm^{-1}$ and also verified by $^1H$ NMR spectrum at 3.4 ppm.
The glass transition temperature of carboxylated PPO increased slightly with increasing degree of carboxylation around 220℃.
Carboxylated PPO phase inversion membranes were prepared with varying the preparation conditions. Increasing THF content in the casting solution caused increase in the solute rejection and decrease in the permeate flux and with increasing the evaporation period, it was shown that solute reject was decreased and permeate flux was increased in the mixture solvents of THF and DMF.
Brominated PPO was synthesized by radical reaction using flood lamp and it was characterized by FT-IR and NMR. The glass transition temperature of brominated PPO decreased slightly with increasing degree of bromination and dense membranes prepared from brominated PPO showed hydrophobic nature.
Aromatic polyamide was synthesized by low temperature polycondensation reaction. Glass transition temperature of aromatic polyamide was observed at 260℃ and its melting temperature was also observed around 420℃.
In case of aromatic polyamide phase inversion membranes, solute rejection was increased with increasing evaporation period at 100℃ and NMP content in coagulation bath.
Carboxylated PPO/Aromatic polyamide blend membrane was prepared with compatibilizer, but it showed no salt rejection because of immicibility of two polymers.
