CONDUCTING THERMOSET POLYMERS - A COMPARATIVE-STUDY OF SCHIFF-BASE PRECURSORS WITH DIFFERENT END-GROUPS

Five different Schiff base monomers were used to form thermoset polyme rs by hot-melt processing. The study included three monomers with the same backbone structure but terminated with acetylene, vinyl or epoxy end groups, respectively, as well as two additional monomers with acet ylene end groups but having different backbone structures. In this way we have compared the effect of the backbone and the crosslink structu res on the electrical conductivities following p-type doping by molecu lar iodine. Two thermosets formed from acetylene-terminated monomers e xhibited conductivities which were approximately a factor of ten highe r than that measured in the thermosets formed from either vinyl- or ep oxy-terminated monomers. The iodine dopant showed a non-Fickian Case I I type of diffusion behavior in all thermosets. Electron spin resonanc e and optical spectroscopy showed evidence for the existence of polaro ns.