Abstract Systematic research on the synthesis, chemical oxidative polymerization of 3, 4- ethylenedithiathiophene (EDTT) in the presence of surfactants or not, and solid-state polymerization of 2, 5-dibromo-3, 4-ethylenedithiathiophene (DBEDTT) and 2, 5-diiodo-3, 4- ethylenedithiathiophene (DIEDTT) under solventless and oxidant-free conditions has been investigated. Effects of oxidants (Fe 3+ salts, persulfate salts, peroxides, and Ce 4+ salts), ...