A fluorine containing monomer was synthesized and its polymer was prepared by aromatic nucleophilic substitution polycondensation of the monomer and 4,4′ difluorobenzophenone using potassium carbonate as the catalyst and tetramethylene sulfone as solvent. The polymer properties were characterized by FTIR, NMR, DSC and the results showed that the T g of the polymer is 141 ℃ and the solubility of the polymer was obviously improved due to the introduction of (3 trifluoromethyl)phenyl group.
Crystallographic equivalence of ether and ketone in all para substituted PAEKs crystallized in form Ⅰ was discussed in this paper. In a word, crystallographic equivalence between ether and ketone groups is tenable when polymer contains only phenyl rings in the repeat unit. If a polymer contains a diphenyl group in the repeat unit, two cases should be distinguished. In the case of PEDEKK and PEEKDK, crystallographic equivalence between ether and ketone linkages is untenable. However, in the case of PEDK and PEDEKDK, crystallographic equivalence between ether and ketone linkages is still tenable.
