A Study on Synthesis and Properties of Poly(2-(2-carboxylic acid-benzamido)- phenylenevinylene) and Its copolymers

2-phthalimido-1,4-bis(bromomethyl)-phenylene monomer for a novel poly(2-(2-carboxylic acid-benzamido)- phenylenevinylene)(CB-PPV) was synthesized through the photo-bromination under UV exposure. CB-PPV has both amido and carboxylic acid side groups. Thus, CB-PPV is a polyelectrolyte, but can be dissolved into the organic solvents to form a light yellow thin film by spin-coating. The carboxylic acid-benzamido side group induces strong blue shift to the UV and PL spectra of PPV, and thus decreases the absorption in visible light. In addition, the carboxylic acid in side group exhibits a similar effect of self-doping. Accordingly, the conductivity of CB-PPV thin film can achieve an order of 10-6 S/cm. Therefore, the CB-PPV introduces a chance for fabricating a transparent conducting thin film. Besides, the copolymers of blue emissive CB-PPV and red emissive MEH-PPV in different composition ratios are synthesized and their photoluminescence properties are basically dependent on their compositions. Furthermore, the preliminary study reveals that the copolymers can also be applied to solar cells.