Chemical and electrochemical synthesis of crosslinked aniline sulfide resin

Abstract

A strategy was used to control the crosslinking of polyaniline (PANi) to allow the synthesis of high-molecular-weight, conductive copolymers. Aniline sulfide resin (ASR) was synthesized by the reaction of aniline and sulfide dichloride. Crosslinked ASR (ASC) was prepared in the presence of ammonium peroxydisulfate and aniline in an aqueous solution as the oxidant and monomer, respectively. The graft copolymer was obtained by oxidizing aniline on ASR in the presence of an initiator and an excess amount of aniline, in which the aniline was oxidized to form PANi through a radical cation mechanism. By changing the ratio of ASR to aniline during the polymerization reaction, it was possible to control the number of crosslinked sites, the electrical conductivity, the molecular weight and the solubility. The structure was characterized by spectroscopic data. The method introduced here describes a strategy for controlling the molecular weight of PANi and in turn its physical properties. This approach may be extended to the synthesis and modification of other polymers. Electropolymerization was carried out by coating ASR on the surface of a glassy carbon disk electrode and then growing this on graft copolymer ASC in the presence of fresh aniline and an acidic solution. The electrical conductivity of ASC was studied by a four-point probe method and produced a conductivity of 8.5 × 10 3 S cm-1. © The Society of Polymer Science, Japan (SPSJ).