The synthesis, thermal, and conduction properties of blends prepared from poly(4-vinyl-imidazole), P-4VI, and phosphoric acid are reported. The number of moles of phosphoric acid per polymer repeat unit, x, was varied from 0 less than or equal to x less than or equal to 2. These blends can be cast into homogeneous films. Thermogravimetric analysis (TGA) illustrates that these blends are chemically stable up to about 150 degreesC. Differential scanning calorimetry (DSC) shows that the softening temperature of the blends decrease from 77 degreesC for x = 1 to - 8 degreesC for x = 2. The DC conductivity increases with x and reaches similar to 10(-4) S/cm for x = 2 at ambient temperature. (C) 2001 Elsevier Science B.V. All rights reserved.