Application of factorial experimental design to study the influence of polymerization conditions on the yield of polyaniline powder

Influences of chemical oxidation polymerization conditions on the yields of polyaniline powder were investigated. These chemical oxidation polymerization conditions included polymerization time, concentration of HNO₃, mol ratio of ammonium persulfate/aniline (APS/AN), and polymerization temperature. If polymerization time, concentration of HNO₃, mol ratio of APS/AN, and polymerization temperature were 60 rain, 1.0 M, 1.0, and 0°C, respectively, then the yield of emeraldine base form polyaniline powder was around 78.1%. The yield of polyaniline powder increased significantly with the polymerization time, concentration of HNO₃, and the mol ratio of APS/AN. A 2³ factorial experimental design was applied to study the main, two-factor interaction, and three-factor interaction effects of polymerization time, concentration of HNO₃, and mol ratio of APS/AN on the yield of polyaniline powder. According to the definition, the sequence of the main effects on the yield of polyaniline powder, in ascending order, is concentration of HNO₃ < mol ratio of APS/AN < polymerization time. The sequence of the two-factor interaction effects on the yield of polyaniline, in ascending order, is concentration of HNO₃ vs. mol ratio of APS/AN < polymerization time vs. concentration of HNO₃ < polymerization time vs. mol ratio of APS/AN. Meanwhile, the prediction equation by definition is: Ŷ = 0.287+0.145X₁+0.091X₂+0.121X₃+0.023X₁X₂+0.111X₁X₃+0.002X₂X₃+0.003X₁X₂X₃.