Poly[2-methoxy-5-(2';-ethylhexyloxy)-(p-phenylenevinylene)] (MEH-PPV) synthesized via a modified Gilch method and the electrical conductivities of MEH-PPV/MCMB films

Poly[2-methoxy-5-(2'-ethylhexyloxy)-(p-phenylenevinylene)] (MEH-PPV) was obtained via the modified Gilch route. The expected polymer was obtained in an overall yield of 19.5%. The structures of all synthesized intermediates and MEH-PPV fully complied with their respective spectroscopic data using 1 H and 13 C nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) spectroscopies. Thermal properties of the polymer was studied using simultaneous thermogravimetry and differential scanning calorimetry (TGA/DSC) and morphologies by transmission electron microscopy (TEM). The glass transition temperature, Tg, of MEH-PPV was obtained at 85°C. TEM results showed that the material was amorphous. Results showed that pure MEH-PPV exhibited high impedance at room temperature but the impedance increases in the MEH-PPV/MCMB composite. The MEH-PPV/MCMB composite film shows an increase in conductivity of the order of 2. The enhancement of conductivity of MEH-PPV by the addition of MCMB was attributed to the change in morphology of the film and contribution of electrons by carbon in the polymer matrix.