Crystal Structure and Thin Film Morphology of BBL Ladder Polymer

TitleCrystal Structure and Thin Film Morphology of BBL Ladder Polymer
Publication TypeJournal Article
Year of Publication1995
AuthorsH.H. Song, A.V. Fratini, M.L. Chabinyc, G.E. Price, A.K. Agrawal, C.S., J. Burkette, D.S. Dudis, and F.E. Arnold
Date PublishedMAR 1

Crystal structure and morphology of poly[7-oxo-7H-benz(d,e)imidazo(4',5':5,6)-benzimidazo(2,1-a)isoquinoli ne-3,4:10,11-tetrayl)-10-carbonyl] (BBL) ladder-like polymer were studied. The polymer forms a two-dimensional lattice of nematic liquid crystalline structure, An orthorhombic unit cell with cell parameters of a = 7.87 b = 3.37 c = 11.97 Angstrom was determined from the fiber diffraction pattern. In thin films, the rigid chains spontaneously form a layered structure across the film thickness, but in a very unusual manner, i.e. the very large molecular plane is standing perpendicularly to the film surface plane. The results are identical to our recent results of poly (p-phenylene benzobisthiazole) (PBT) film[7]. The polymer, however, lost its anisotropic order upon extrusion into a film and resulted in a fiber-like structure.