Synthesis and characterization of poly(o-methoxyaniline)–lignosulfonate composites

[Display omitted] ► Poly(o-methoxyaniline)-lignosulfonate (POMA-LGS) composites were synthesized. ► Effect of LGS content on physical and chemical properties was investigated. ► Composite formation mechanism was proposed. ► Sulphate from oxidant was found to serve as the main dopant instead of LGS. Poly(o-methoxyaniline)–lignosulfonate (POMA–LGS) composites were synthesized through oxidative chemical polymerization of o-methoxyaniline by ammonium persulfate (APS) in the presence of sodium lignosulfonate (NaLGS). The structure of the composites was investigated using FTIR, UV–vis spectroscopies and SEM. The AC conductivity and free radical scavenging of the composites were also tested. The LGS content was found to have a strong influence on the structure and properties of the composites. A higher LGS content led to composites with a higher AC conductivity, a higher specific surface area, as well as a greater radical scavenging capacity. A new composite formation mechanism was proposed, with the sulfate group dissociated from the oxidant of APS as the main dopant, POMA particles as adsorbate and LGS as the adsorbent.