Polyfuran

Polyfuran (Pfu) (Figure 1) is a conducting polymer that consists of multiple furan rings connected with each other through carbon-carbon bonds. Polyfuran is synthesized by polymerization of furan monomers. Both chemical and electrochemical strategies have been developed for polyfuran synthesis.

Fig. 1: Chemical structure of polyfuran

A variety of electrochemical approaches have been developed for polyfuran synthesis. Parameters such as the electrolyte and the electrode used, the temperature at which the polymerization reaction proceeds, and the reaction media will all affect the quality and property of the polyfuran polymer. Most important factors are the choice of the solvent and the electrolyte used, because the polymerization reaction is sensitive to the nucleophilicity of the environment near the surface of the electrode. The best condition for electrochemical synthesis of polyfuran is to apply a constant potential to a furan solution with concentration higher than that of electrolyte in aprotic solvent. Different mechanisms have been proposed for the electrochemical polymerization of furan. The mechanism proposed by Diaz involving formation of radical cation is most accepted.

Chemical methods for polyfuran synthesis usually use acidic catalysts. Armour et al were the first to use an acid catalyst (trichloroacetic acid) to catalyze the polymerization of furan, the polymer was produced with 20% yield by applying the catalyst to furan for 170 hours at 20 oC. Other methods have also been developed for polyfuran synthesis using different polymerization approaches such as [[radical polymerization]] and oxidative cationic polymerization.

Electrochemical synthesis of polyfuran is more often used compared to chemical methods. By controlling different parameters during electrochemical polymerization, one can obtain polyfuran polymers with different conductance and processing properties.