Characterization of antioxidant low density polyethylene/polyaniline blends prepared via extrusion

Blends of linear low density polyethylene (LLDPE) and nanorod-polyaniline (NR-PANI), formed by a falling pH synthesis, were prepared by dispersing NR-PANI in the melt of LLDPE at 150 degrees C. The blends had 5, 10,15 and 20 wt% loading of NR-PANI. ESEM images revealed an even dispersion of NR-PANI in the LLDPE matrix. Coalescence of NR-PANI particles and an increase in electrical conductivity was observed at higher loading of NR-PANI. The blends were characterized further using FTIR, XPS, ESR, XRD and DSC. The blends exhibited characteristic vibrational bands due to both LLDPE and NR-PANI, but did not show any chemical interaction between the components. With an increased loading of NR-PANI in the blends, the amount of NR-PANI present on the surface of the samples increased, and the crystallinity of LLDPE decreased. The tensile strength and elongation at break of LLDPE also declined suggesting a lack of interfacial adhesion between the NR-PANI particles and the LLDPE matrix. The Young's modulus, however, increased with higher loading of NR-PANI. The blends also demonstrated very good free radical scavenging activity, dependent upon the amount of NR-PANI included in the blends. (C) 2012 Elsevier B.V. All rights reserved.