Synthesis and characterization of aromatic polymers derived from 5-perfluoroalkylisophthalic acid

A series of polyisophthalamides and polyisophthalates having perfluorinated side chains were prepared from 5-perfluoroalkylisophthaloyl dichlorides. T he aromatic polyamides and polyarylates synthesized by conventional low tem perature solution polycondensation and interfacial polycondensation, respec tively, had inherent viscosities of 0.19 to 1.28 dL g(-1) in yields of 65 t o 100%. Solubilies of the resulting polymers were improved by incorporating nonafluorobutyl groups but not improved by incorporating heptadecafluorooc tyl groups. Although the effect on the glass transition temperature (T-g) o f incorporating perfluoroalkyl groups into the aromatic polyamides or polya rylate backbone is great, the incorporation maintained the thermal stabilit y of the polymers. In spite of the rigid nature of perfluoroalkyl groups, T (g)s were decreased by incorporating perfluoroalkyl groups. The value of th e contact angle of water on the aromatic polyamides films gradually increas ed with incorporation of the perfluoroalkyl groups. On the other hand, the value of the contact angle remarkably increased when perfluoroalkyl groups were incorporated into polyarylates. The Owens ys were also calculated for some aromatic polyamides by measuring contact angles of diiodomethane on th e polymer films. The gamma s were estimated at 23-37 mN m(-1) and about 10% of them were contributed by hydrogen bonding. (C) 1999 John Wiley & Sons, Inc.