Oriented double gyroid films via roll casting

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