Acetylene-norbornene copolymers

Abstract

Metathesis ring opening polymerization has been used to copolymerize norbornene and 7,8-bis(trifluoromethyl)tricyclo[4,2,2,0^2,5]deca-3,7,9-triene. Subsequent thermal elimination of the precursor copolymers yielded acetylene-norbornene copolymers. The undoped copolymers were found to have electrical conductivity, spin concentration, and EPR linewidths which vary with composition. The location of the trans-C-H out-of-plane vibration, however, was invariant at 1010cm^-1 indicating that conjugation length of n > 4 are present even at 40% acetylene content in the copolymer. The copolymers containing 79 mol % of acetylene units attained a doped conductivity of 0.02 S/cm with a dopant concentration of 6 mol % of I̅₃ per sp² carbon.