Charge storage in pure and titanium dioxide doped polyarylate, and conduction in pure polyarylate

Abstract

Charge storage of cast, pure and titanium dioxide doped amorphous polyarylate films was studied using thermally stimulated charge decay and thermally stimulated currents (TSC). Optimum storage was obtained by corona charging at 180°C, using 10 wt% titanium dioxide. A half value charge decay temperature ( T 1 2 ) of 180°C at 30% R.H. was then obtained. This value is 54°C higher than the T 1 2 of 126°C obtained for room temperature charging. Pure polyarylate charged at 180°C had a T 1 2 of 126°C, the same as that for room temperature charging. Both dopant-matrix boundaries and/ or additives themselves may act as deep traps. Steady state current-field ( F) curves of pure polyarylate follow a sinh law in F/ kT in the temperatuer range 87–143°C, favouring carrier hopping as the conduction mechanism. An activation energy of 1.1 eV was obtained from thermally stimulated polarization currents, and agreed with that obtained from a hopping conduction theory.