Oscillatory shear flow-induced alignment of lamellar melts of hydrogen-bonded comb copolymer supramolecules

In this work we present the orientational behavior of comb copolymer-like supramolecules P4VP(PDP)(1.0), obtained by hydrogen bonding between poly(4-vinylpyridine) and pentadecylphenol, during large-amplitude oscillatory shear flow experiments over a broad range of frequencies (0.001-10 Hz). The alignment diagram, presenting the macroscopic alignment in T/T-ODT vs omega/omega (c), contains three regions of parallel alignment separated by a region of perpendicular alignment. For our material, the order-disorder temperature T-ODT = 67 degreesC and omega (c), the frequency above which the distortion of the chain conformation dominates the materials' viscoelasticity is around 0.1 Hz at 61 degreesC. For the first time flipping from a pure transverse alignment via biaxial transverse/perpendicular alignment to a perpendicular alignment as a function of the strain amplitude was found.