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4706691 
Journal Article 
Formation of Tetragonally-Packed Rectangular Cylinders from ABC Block Terpolymer Blends 
Asai, Y; Yamada, K; Yamada, M; Takano, A; Matsushita, Y 
2014 
3 
2 
166-169 
English 
35590498 
WOS:000331774200010 
Effect of composition distribution of ABC linear terpolymers on the formation of periodic structures was investigated. Five poly(isoprene-b-styrene-b-2-vinylpyridine) (ISP) triblock terpolymers with almost constant molecular weights of ca. 130k and with similar center-block fraction at around 0.55, were blended variously. It has been found that tricontinuous gyroid structures gradually transform into a cylindrical structure whose rectangular cylinders are packed tetragonally if composition distribution increases. Further experiments by 3D-TEM observation on binary equimolar mixtures of two molecules with similar molecular weights of 122k and 124k, giving the average composition of phi(1)/phi(S)/phi(P) = 0.23/0.59/0.18, has verified to show more evident rectangular-shaped cylinders with 4-fold symmetry. This new structure, having periodic surfaces with nonconstant mean-curvature, could be formed due to the systematic localization of component polymer chains along the domain interfaces.