Layer structure estimation of three-dimensional crystal and two-dimensional molecular film for fluorinated comb copolymers

Abstract

Comb copolymers containing both hydrogenated and fluorinated side-chains were prepared by copolymerization using acrylic or methacrylic monomers in several ratios. The crystal structures of these copolymers and layer structures of their organized molecular films were investigated by wide-angle X-ray diffraction (WAXD), small-angle X-ray scattering (SAXS), and out-of plane X-ray diffraction. Further, to selectively estimate the regularity of shorter fluorocarbon side-chains, organized molecular films of copolymers were investigated by polarized near-edge X-ray adsorption fine structure (NEXAFS) spectroscopy. From the results of these measurements, it was inferred that these copolymers formed highly ordered layer structures, and a long spacing was predominantly determined by the arrangement of hydrogenated side-chains, except in copolymers having extremely high fluorocarbon contents. In the case of the organized molecular films, the fluorinated side-chains of methacrylate copolymers cannot form a highly ordered arrangement, whereas those of acrylate copolymers were oriented on monolayers. However, in both cases, the hydrogenated side-chains predominantly formed layer structures in the organized films, and the fluorinated side-chains did not contribute to the formation of the layer structures. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 534–546, 2008