Oriented double gyroid films via roll casting

Films of an isoprene-rich poly (styrene-b-isoprene-b-styrene) (SIS) triblock copolymer thermoplastic elastomer having a highly textured double gyroid (DG) morphology were produced via roll casting and annealing. The symmetries of the extensional and shear flows involved in the roll casting process are not commensurate with those of the cubic Ia (3) over bar d symmetry of the tricontinuous, triply periodic cubic DC phase. Upon roll casting the microdomain morphology produced is predominantly that of cylinders, oriented with the axes along the roll cast direction. Upon annealing, the DG phase nucleates and grows with the [111] direction oriented along the roll cast direction. The resultant textured films are suitable for investigating the directional dependence of physical properties. (C) 2000 Elsevier Science Ltd. All rights reserved.