High intrinsic conductivity in ladder type polymers: Pyrolyzed BBB

Abstract

Through electrical conductivity and ESR measurements of ' heat treated BBB-rigid-rod ladder polymers, we provide evidence for the existence of an irreversible transformation to another cross-linked ladder polymer with high intrinsic conductivity. The transformation occurs at a pyrolysis temperature, Ts = 680°C. The results suggest a novel transport mechanism.

Rigid‐Rod Polymers: Synthesis, Processing, Simulation, Structure, and Properties

“…Investigations have been made in regard to the effect of heat treatment on electrical conductivity in poly(benzimidazobenzophenanthroline) (BBL)323,324 The conductivity of BBL films were found to increase from roughly 10 −9 S/cm to 10 −8 S/cm on annealing at temperatures less than 580 °C. However, at temperatures above 630 °C, the conductivity rose to 1 S/cm.…”

Some Heterocyclic Polymers and Polysiloxanes

“…Some poly(/7-phenylene-l,3,4-oxadiazole) (POD) [143,144], and polybisbenzimidazobenzophenanthroline (BBB) [145]. For the pyrolysis method, it has been demonstrated that the transformation procedure of insulator to semiconductor or conductor is accompanied by a structural change, that is, a graphite-like structure, which is a large, planar, dense heterocyclic network with ^-conjugation and strong ir-orbital overlapping formed after pyrolysis [141].…”