Preparation and Characterization of Conductive HDPE/LLDPE/Polyaniline Blends

The electrical properties of conducting polymer and insulating polymer matrix combined with attractive mechanical properties and processing advantages of the polymers has now attained a level of maturity consistent with a new set of opportunities to develop a wide range of application based conducting polymer composites. Polyaniline has been widely investigated due to its low cost, easy synthesis and high electrical conductivity. The purpose of this work was to prepare high density polyethylene (HDPE)/linear low density polyethylene (LLDPE)/polyaniline (PANI) blends with 5, 10, 15, 20 and 40 wt% of polyaniline by melt compounding in a torque rheometer. The final blends were prepared with a blend ratio of 1:1 HDPE/LLDPE. The PANI was synthesized by a following a well-established method for the synthesis of the emeraldine base form using HCl as dopant. The HDPE/LLDPE/PANI blends were analyzed by FTIR, mechanical, thermal and electrical properties. Usually, polymer blends with PANI were prepared by solution or compression of powders. In this work the composites were successfully prepared by melt compounding and it was observed an increase in the equilibrium torque with addition of polyaniline and there was no degradation of the polymer matrix or PANI. FT-IR spectrum analysis was performed to identify the bonding environment of the synthesized material and was observed that simply physically mixture occurred between PANI and HDPE/LLDPE blend. Tensile tests showed reduction of Young's modulus only for the blend with 40 wt% of PANI, however a decrease in elongation at break was observed. On the other hand, the addition of polyaniline increased the electrical conductivity. The HDPE/LLDPE blend showed a conductivity of 6.5x10(-11) S/cm and the addition of 40wt% of PANI increased the electrical conductivity for 3.7x10(-6) S/cm.