Application of statistical design strategies to optimize the conductivity of electrosynthesized polypyrrole

Fractional factorial design (FFD) and response surface methodology (RSM) coupled with central composite design (CCD) were used to optimize the electrical conductivity of polypyrrole (PPy) synthesized through an electrochemical route and constant current electrolysis. Current density of polymerization, monomer concentration, electrolyte (lithium perchlorate) concentration and temperature were selected as variables to study the effect on electronic conductivity of PPy through FFD. The temperature and concentration of the electrolyte are identified as the key variables which influence the conductivity of PPy. An empirical equation for the conductivity of PPy with variables is obtained via regression analysis. A contour plot is generated which predicts that a high value for the conductivity for PPy (ca. 34.3 S cm⁻¹) can be obtained with the LiClO₄ concentration of 0.826 M and a temperature of 14.9 °C. The results from confirmation experiments justify the prediction from the statistical approach.