Molecular Orientations in Flat-Elongated and Helical Lamellar Crystals of a Main-Chain Nonracemic Chiral Polyester

摘要: Single flat-elongated and helical lamellar crystals have been grown thermotropically in a main-chain nonracemic chiral liquid crystalline polymer that was synthesized from (R)-(−)-4‘-{ω-[2-(p-hydroxy-o-nitrophenyloxy)-1-propyloxy]-1-nonyloxy}-4-biphenyl carboxylic acid, PET(R*)-9. The possess the identical orthorhombic lattice dimensions of = 1.07 nm, b 0.48 c 5.96 nm.1,2 Dark field (DF) image, bright selective area electron diffraction (SAED) experiments using transmission microscopy (TEM) provide chain orientation information both these crystals. In crystals, direction is perpendicular to substrate surface center zone along long (b) axis Moving away this short (a) crystal, continuously tilts ac-plane. A small tilt approximately 0.002° per molecular layer estimated SAED results. crystal...