SYNTHESIS, CHARACTERIZATION, AND STABILITY OF POLY(3,4-DIBUTOXYTHIOPHENEVINYLENE) COPOLYMERS

Poly(3,4-dibutoxythiophenevinylene) was prepared in two steps using nickel-catalyzed Grignard coupling reactions with 1,2-dichloroethylene to yield a high molecular weight polymer that could be cast into tough free-standing films. The visible spectrum showed an absorption maximum of 607 nm and a band gap of 1.62 eV. Doping with FeCl3 turned the deep blue film to transparent light gray and resulted in a conductivity of 1 S cm-1 using the four-probe technique. DSC measurements revealed no T(g) but showed a T(m) at 168-degrees-C. The unusual partial crystallinity was confirmed by wide-angle X-ray diffraction. The polymer exhibited good thermal stability but was susceptible to photooxidation and to reaction with ambient levels of ozone. Poly-[bis(3,4-dibutoxythienylene)vinylene] was also prepared and characterized.