New proton conducting polymers based on poly(silamine) (PSA) were synthesized by complexing the polymer and H3PO4, and the proton conduction of these materials was investigated. The PSA/H3PO4 complex was thermally stable up to 200 degrees C, as indicated by TG/DTA analysis. The conductivity of 10(-5) S cm(-1) was observed at 160 degrees C for anhydrous PSA/H3PO4 complexes with a concentration of 0.8 H3PO4 per repeat unit. The carrier ion was proven to be proton on the basis of the H/D isotope effect on conductivity for PSA/H3PO4 and PSA/D3PO4 complexes. (C) 2000 Elsevier Science Ltd. All rights reserved.