| 초록 |
Partially sulfonated block copolymers for proton exchange membranes were synthesized by three steps: synthesis of telechelic polymers, synthesis of block copolymers with these telechelic polymers, and partially sulfonation of block copolymers as following. A series of block copolymers were prepared by coupling reaction through two types of telechelic polymers, polystyrene (PS) and poly(arylene ether)s (PAE). PS end-functionalized with anhydride group was synthesized by living anionic polymerization and PAE end-bifunctionalized with amino group was synthesized by condensation polymerization. The molecular weights of telechelic polymers were controlled from 6000 to 30 000 g/mol for various compositions of block copolymers. The new kind of block copolymers, PS-PAE-PS, showed high thermal stability due to existence of phenyl ether and sulfone groups of PAE blocks. The phase behavior characterized by AFM showed the various conformations with different composition of PAES domains in block copolymers. PS-PAE-PS triblock copolymers were partially and selectively sulfonated by introducing sulfonic group in PS blocks for proton exchange membranes, which were prepared at various sulfonation levels and compositions of PS and PAES blocks. Effects of sulfonation levels and composition of blocks on proton conductivity and thermal stability were investigated. Methanol permeability and water uptake were measured for application as direct methanol fuel cell (DMFC). |
