The insulator-to-conductor transition in sulphonated poly(phenylene oxide)polymer membranes: Percolation theory approach

In this paper the percolation theory is employed to study the insulator-to- conductor transition in sulphonated poly(phenylene oxide) (SPPO) polymer me mbranes. The membranes with different sulphonation degree were prepared and infrared characterized. The transition threshold was calculated by the exp erimental data of membrane conductivities and the coordination number was t hus estimated. The functional group -SO3H distribution in the membrane was evaluated in accordance with the calculations and showed a non-random dispe rsion on the microscopic scale.