High Performance Polymers, 2nd Edition

15: POLY(IMIDE)S 351

decreases the conductivity of the membrane electrode

assembly.

Crosslinked sulfonated poly(imide-siloxane) can be

obtained by the radical grafting onto the silylmethyl

group of poly(dimethylsiloxane) [59]. Large, well-

connected hydrophilic domains have been detected by

transmission electron microscopy that are responsible

for the high proton conductivity of the membrane. The

unique phase separated morphology of the membrane

is responsible for the outstanding hydrolytic stability.

Sulfonated PI membranes have been synthe-

sized by the thermal imidization with monomers of

4,4



-(hexafluoroisopropylidene)diphthalic anhydride,

4,4



-diaminodiphenyl ether-2,2



-disulfonic acid, and

3,3



-diaminochalcone [60]. Chalcone is basically pho-

tosensiti ...