M. Shahinur Rahman

Formation of Intermicellar-Chained and Cylindrical Micellar Networks From an Amphiphilic Rod—Coil Block Copolymer: Poly(n-hexyl isocyanate)-block-poly(2-vinylpyridine)

Morphologies of the poly(n-hexyl isocyanate)-block-poly(2-vinylpyridine) (PHIC-b-P2VP, fP2VP=0.3) amphiphilic rod-coil block copolymer were studied in rod-selective chloroform (CHCl3), both-block-soluble tetrahydrofuran (THF), and CHCl3/THF mixed solvent systems. Spherical, solid micelles with a P2VP core and PHIC shell were formed in CHCl3, whereas a microphase-separated liquid crystalline morphology was prominent in the presence of THF. In the CHCl3/THF mixed solvent system, a unique long-range intermicellar-chained network (v/v=7/3) and a more evolved cylindrical micellar network (v/v=3/7) were remarkably formed, respectively. PHIC-b-P2VP network nanostructures were used as a template for the in situ synthesis of Au nanoparticles (8 nm) selectively within the functional P2VP core domains.

Effect of Molecular Structure on Rheological Behavior of Nearly Monodisperse H‐Shaped Polybutadienes

Nearly monodisperse H‐shaped Polybutadiene (PBD) with high 1,4 microstructure (∼90%) were synthesized by a novel synthesis strategy of living anionic polymerization. Linear viscoelastic properties over a broad frequency range of a linear PBD and an H‐shaped PBD were studied by frequency sweep and creep/recovery experiments. The dynamic moduli of all samples were found to obey the time‐temperature superposition. Primary attention was given to properties that depend on chain microstructure: the plateau modulus QN0, the steady state compliance Js0, and the horizontal and vertical temperature shift factors for the frequency and modulus, aT and bT. The data are compared with the predictions of a hierarchical model developed by Larson.