LATTICE IMAGING OF HBA-HNA NONPERIODIC LAYER CRYSTALS

Solution cast thin films of the Vectra(RM) HBA-HNA thermotropic liquid crystalline random copolymer, annealed for 1 h at 240 degrees C have been investigated by HREM. Non-periodic layer crystals were observed w ith the c direction lying in, or close to the plane of the films, wit h crystalline core widths of about 10 nm. Lattice fringes were obtaine d from the 110 and 200 planes of the orthorhombic unit cell, and from the first of the non-periodic meridional maxima of the fibre diffracti on pattern, these latter extending over the whole of the core widths. (C) 1997 Elsevier Science Ltd.