Preparation of a multiblock terpolymer and its hierarchical nanophase-separated structure

A three component hexablock terpolymer of the ABABAC type(Fig. 1) was successfully prepared by sequential living anionic polymerization. Polyisoprene(I), polystyrene(S) and poly(2-vinylpyridine)(P) were used as polymer components A, B, and C, respectively. The estimated number average molecular weight of each block chain is 6K(I), 12K(S), 9K(I), 20K(S), 15K(I), 507K(P). It was confirmed by morphological observation that the terpolymer forms hierarchical spherical structure, in which core-shell spheres from I and S phases are embedded in matrix of P. At least two kinds of spheres were observed, one is the three-layered isolated domain with I core and the other is the four-layered one with S core.