Conducting nanocomposites of polyacrylamide with acetylene black and polyaniline

A conducting nanocomposite of polyacrylamide (PAA) with acetylene black was prepared via Na₂AsO₃‐K₂CrO₄ redox initiated polymerization of acrylamide in water containing a suspension of acetylene black. FTIR analyses confirmed the presence of PAA in the nanocomposites. The composite possessed lower thermal stability than AB and exhibited three stages of decomposition upto 430°C. DSC thermogram revealed three endotherms due to minor thermal degradation (at ∼100°C), melting and decomposition (at ∼230°C) and major decomposition (at ∼430°C). TEM analyses indicated the formation of globular composite particles with sizes in 30–70 nm range. In contrast to the very low conductivity of the base polymer the composite showed a dramatic increase in conductivity (0.19–6.0 S/cm) depending upon AB loading. Log (conductivity) –1/T plot showed a change in slope at ∼127°C indicating the manifestation of an intrinsic conductivity region and an impurity conductivity region. The activation energy for conduction as estimated from the slope of region I was 0.008 eV/mol. The C–V plot was linear showing a metallic behavior. For comparison in conductivity PAA‐polyaniline composite was also prepared which however displayed much lower conductivity values. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers