Ye Zhu,Hai-Bo Zhang,Lian-Jun Ding,Zheng Chen,Da-Ye Sun,Zhen-Hua Jiang
Perfluorocarbon groups or related compounds are usually used to modify polymer materials because of their low surface energy properties. In this paper, a novel perfluorocarbon-containing compound was synthesized and used as a capping agent for the preparation of perfluorocarbon chain terminated poly(ether sulfone). The regulation of the fluorine content was achieved by controlling the molecular weight. FTIR and 1H NMR spectra were used to confirm the existence of perfluorocarbon terminated groups in the polymer chains. In addition, the ratios of F/C were acquired by integral area calculation from the 1H NMR spectrum. XPS characterization showed that the surface migration phenomenon of fluorine became apparent along with the increase of the F/C ratio. Further testing found that the introduction of perfluorinated end groups into the PES chains had little influence on the polymers' mechanical and thermal performance, by contrast, their surface energy decreased efficiently from approximately 40 mJ m−2 to 16 mJ m−2 with the F/C ratio on the surface increased from 0 to 0.556, which could develop PES as a low surface energy material for industrial applications.
Xiaoqing Wu,Baining Ni,Limin Wu,Yongmin Guo,Yi Li,Baozong Li,Yonggang Yang
Eight dichiral compounds containing two lactic acid residues and one perfluorocarbon chain are synthesised. Six of them are liquid crystals with an enantiotropic SmA phase. Two of them are liquid crystals with enantiotropic SmA and SmC* phases. Although (R,R)-3 and (R,R)-4 molecules pack in monolayer structures at the crystalline states, (S,R)-3 and (R,S)-4 molecules pack in bilayer structures at the crystalline states. The optical activity of these compounds is mainly controlled by the chirality of the lactic acid residue near the liquid crystalline core. The dichiral compounds can self-assemble into nanotubes or twisted nanoribbons in methanol. Circular dichroism characterisation indicated that the stacking handedness of the liquid crystalline cores in the organic self-assemblies was also dominated by the chirality of the lactic acid residue near the liquid crystalline core.
危险品化学品经营许可证（带存储）