Synthesis, Characterization, and Conductivities of Poly(2-Vinylpyridine)-graft-Polyoxyethylene using a Macromer Technique

Poly(2-vinylpyridine) (P2-VP) with uniform polyoxyethylene (PEO) grafts was synthesized using a macromer technique. 2-Vinylpyridine was copolymerized with PEO macromer in solution by using azobisisobutyronitrile (AIBN) as the initiator. The effects of the amount of AIBN, the concentrations of 2-vinylpyridine and macromer, the number-average molecular weight of macromer, and the charging ratio of macromer to 2-vinylpyridine in the copolymerization were studied. The copolymerization rate of the PEO macromer with 2-vinylpyridine was also investigated. The grafting efficiency reached about 56%. The crude graft copolymer was purified by extraction and precipitation, and it was characterized by IR, ^!H-NMR, and Bruss membrane osmometry. The PEO grafts were doped with LiC10₄ and showed ionic conductivity around 4.10 × 10“⁶ S.cmat -1 25°C whereas the P2-VP main chains were complexed with TCNQ to obtain electronic conductivity around 5,50 × 10 ^{- 6} S’cm’¹ at 25 °C. The mixed (ionic and electronic) conductivity of the doped copolymer could reach about 5.40 × 10 ^{- 5} S-cm^-1 at 25 °C and showed a synergistic effect.