Chemical preparation of conductive elastomeric blends: Polypyrrole/EPDM. I. Oxidant particle‐size effect

The preparation of polypyrrole and EPDM rubber blends, PPy/EPDM, by the sorption of pyrrole (vapor phase) in an EPDM matrix containing CuCl 2 is described. The effect of the oxidant particle size on the sorption and polymerization equilibrium, electrical conductivity, and mechanical properties of the blends is investigated. Independently of the CuCl 2 concentration and polymerization time, the polypyrrole weight fraction in the blend, X PPy , increases when the oxidant particle-size is changed from 150-250 μm to smaller than 106 μm. For blends containing 50 phr of CuCl 2 , obtained following 72 h of exposure to pyrrole, an increase in the Young's Modulus (from 2.2±0.2 to 3.9±0.6 MPa) and an increase in the electrical conductivity (from 10 -9 to 10 -7 S cm -1 ) was observed when the oxidant particle-size was decreased