Synthesis of fusible and soluble conducting polyfluorene derivatives and their characteristics

Conducting polyfluorene derivatives with alkyl chains—poly(9‐alkylfluorene)s and poly‐(9,9‐dialkylfluorene)s—have been synthesized by chemical polymerization utilizing FeCl 3 as an oxidizing agent. The polymers obtained are found to be soluble in conventional organic solvents such as chloroform and have been characterized by 1 H‐ and 13 C‐NMR. The results indicate that the fluorene moeities are mainly linked in the 2,7′‐fashion to yield the straight chain polymer. The degree of polymerization is estimated (by gel permeation chromatography) to be of the order of 10. The polymers are found to be fusible and the thermal properties of the polymers have been characterized by differential scanning calorimetry. The glass transition temperature is found to decrease with an increase of the alkyl chain length.