Poly-Schiff bases. V. Synthesis and characterization of novel soluble fluorine-containing polyether azomethines

A new dialdehyde monomer, 4,4'-(hexafluoroisopropylidine) bis(p-phenoxy) be nzaldehyde, was prepared; it led to a number of novel poly-Schiff bases in reactions with different diamines, such as 4,4'-diaminidiphenyl ether, 4,4' -(isopropylidine) bis(p-phenoxy) dianiline, 4,4'-(hexafluoroisopropylidine) bis(p-phenoxy) dianiline, and benzidine. The polymers were characterized w ith viscosity measurements, nitrogen analyses, and IR and H-1 NMR spectrosc opy. These poly-Schiff bases showed good thermal stability up to 491 degree sC for 10% weight loss in thermogravimetric analysis under air and high gla ss-transition temperatures up to 215 degreesC in differential scanning calo rimetry. These polymers were soluble in a wide range of organic solvents, s uch as CHCl3, dimethylformamide (DMF), dimethyl sulfoxide, and 1-methyl-2-p yrrolidon (NMP), and were insoluble in toluene and acetone. Thin films of t hese polymers cast from DMF exhibited tensile strengths up to 38 MPa. (C) 2 000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 383-388, 2001.