Investigation of charge transport properties in conducting copolymers of aniline with 3-aminobenzenesulfonic acid for their applications as antistatic encapsulation materials blended with low-density polyethylene

The electrostatic charge dissipative (ESD) properties of conducting self‐doped and PTSA-doped copolymers of aniline (AA), o‐methoxyaniline (methoxy AA) and o‐ethoxyaniline (ethoxy AA) with 3‐aminobenzenesulfonic acid (3‐ABSA) blended with low‐density polyethylene (LDPE) were investigated in the presence of external dopant p‐toluenesulfonic acid (PTSA). Blending of copolymers with LDPE was carried out in a twin‐screw extruder by melt blending by loading 1.0 and 2.0 wt% of conducting copolymer in the LDPE matrix. The conductivity of the blown polymers blended with LDPE was in the range 10−12–10−6 S cm−1, showing their potential use as antistatic materials for the encapsulation of electronic equipment. The DC conductivity of all self‐doped homopolymers and PTSA‐doped copolymers was measured in the range 100–373 K. The room temperature conductivity (S cm−1) of self‐doped copolymers was: poly(3‐ABSA‐co‐AA), 7.73 × 10−4; poly(3‐ABSA‐co‐methoxy AA), 3.06 × 10−6; poly(3‐ABSA‐co‐ethoxy AA), 2.99 × 10−7; and of PTSA‐doped copolymers was: poly(3‐ABSA‐co‐AA), 4.34 × 10−2; poly(3‐ABSA‐co‐methoxy AA), 9.90 × 10−5; poly(3‐ABSA‐co‐ethoxy AA), 1.10 × 10−5. The observed conduction mechanism for all the samples could be explained in terms of Mott's variable range hopping model; however, ESD properties are dependent upon the electrical conductivity. The antistatic decay time is least for the PTSA‐doped poly(3‐ABSA‐co‐AA), which has maximum conductivity among all the samples. © 2013 Society of Chemical Industry Investigations of the antistatic properties of various poly[(3‐aminobenzenesulfonic acid)‐co‐aniline] (poly(3‐ABSA‐co‐AA)) copolymers and doped with p‐toluenesulfonic acid (PTSA) and at loading levels of 1 and 2 wt% in low‐density polyethylene (LDPE) suggest that the electrostatic charge dissipative properties may depend upon the conductivity of the material which is highest for the copolymers.