Electroactive styrene-isoprene-styrene triblock copolymer: Effects of morphology and electric field

Various morphological films, made of styrene-isoprene-styrene triblock copolymers (SIS), were prepared by solvent casting methods, containing cylindrical, and lamellar structures. The electromechanical properties of the films were investigated under oscillatory shear mode at electric field strengths of 0, 1 and 2 kV/mm as functions of temperature. In two SIS systems, the storage moduli (G') linearly increase with temperature up to 330 K at 1 rad/s in the absence of electric field. The storage modulus responses increase with increasing of electric field up to 1 kV/mm and decreases beyond that. In the deflection experiments, under applied electric field, the deflection distances of SIS film with 19% styrene content (D1114P) and SIS film with 29% styrene content (D1164P) show stepwise increases with increasing electric field strength along with their apparent dielectrophoretic forces, while the other SIS system with 44% styrene content (D1162P) shows zero responses towards applied electric field. (C) 2010 Elsevier B.V. All rights reserved.