Electropolymerization of trimethylsilylphenols to silylated polyphenylene oxides and investigation of their properties. Enhanced conductivity of PPO by silyl group

Abstract

Polymerization of o-, m-, and p-trimethylsilylphenols (TMS-phenols) was achieved electrochemically. The polymers were prepared as thin films on a platinum electrode and were found to be electroinactive in nonaqueous solutions. The polymers exhibited far higher conductivities than polyphenol or other substituted polyphenols. The conductivity of poly (p-TMS-phenol) was lower than that observed for the polymers of the o- and m-isomers. The polymers were characterized by infrared spectroscopy. The effect of monomer concentration, supporting electrolyte concentration, current densities, and temperature on the poymerization was investigated using microgravimetry. The observed empirical kinetics were as follows. The rates of polymerization of o-, m-, and p-TMS-phenol were found to be of 0.8, 0.8, and 0.7 order dependent on monomer concentation, of 0.5, 0.5 and 0.45 order dependent on electrolyte concentration, and of 0.9, 0.9 and 0.8 order dependent on current densities. By investigating the effect of temperature on electropolymerization, the corresponding activation energies of electropolymerization were calculated to be 0.9, 0.9, and 0.8 kj/mole. The molecular weights of poly(o-TMS-phenol) and poly(m-TMS-phenol) were determined by gel permeation chromotography. © 1997 John Wiley & Sons, Inc