Synthesis, Isolation, Characterization, and Properties of Small-Size Armatic Macrocycles for Poly(Arylene Ether Ketone)s

摘要

A series of macrocyclic arylene ether ketone oligomers from 4,4'-difluoro-benzophenone, 2.4'-difluorobenzophenone and 1,3-bis(4'-fluorobenzoyl)benzene were prepared via aromatic nucleophilic substitution according to the pseudo-high dilution principle. Small-size aromatic macrocycles were isolated by silica gel column chromatography with cyclohexane/ethyl acetate as eluent. The chemical structures of these small-size macrocycles were characterized by matrix-assisted laser desorption ionization-time-of-flight-mass spectrometry (MALDI-TOF-MS), IR, ~(19)F-, ~1H-, and ~(13)C-NMR, and GPC techniques. Molecular chain length and steric hindrance of monomers affected the product compositions. The NMR results show that there are different chemical shifts in the different ring-size macrocyclic poly arylene ether ketones in spite of having the same repeating unit. The crystallizability and thermal properties of small-size arylene ether ketone macrocycles were also investigated by DSC, WAXD, TGA, and the results suggest that the crystallization and thermal properties are related to their intrinsic chemical structures.