Synthesis, isolation, characterization, and properties of small-size aromatic macrocycles for poly(arylene ether ketone)s

✍ Scribed by Junzuo Wang; Chunhai Chen; Xiumei Xun; Shiying Wang; Zhongwen Wu

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 227 KB
• Volume: 37
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(19990701)37:13<1957::aid-pola9>3.0.co;2-k

✦ Synopsis

A series of macrocyclic arylene ether ketone oligomers from 4,4Ј-difluorobenzophenone, 2,4Ј-difluorobenzophenone and 1,3-bis(4Ј-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-, 1 H-, 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.