Tetragonally Packed Cylinder Structure of Comb-Coil Block Copolymer Bearing Heteroarm Star Architecture

The tetragonally packed cylinder structure was observed in the of comb-coil PS-P4VP(DBSA) block copolymer bearing heteroarm star architecture, where tetragonal lattice appeared at the intermediate binding fraction of DBSA on P4VP block. The heteroarm star PSn-P4VPn, with the average arm number n of both PS and P4VP blocks being 2.6, was prepared by a three three step sequential copolymerization, and the complexes of the copolymer with DBSA were prepared according to the procedure. The SAXS and TEM results have revealed that the heteroarm PS-P4VP(DBSA) comb-coil copolymer exhibits the same self-assembly behavior as its linear counterpart in terms of the effect of the overall binding fraction of comb block on the packing symmetry of the PS cylinders. The hexagonal packing became stable at the stoichiometric binding that resulted in the orthogonal orientation of the smaller scale lamellae with respect to the PS cylinder, demonstrating the self organization behavior in terms of packing symmetry.