SYNTHESIS AND PROPERTIES OF POLYAMIDES AND POLY(AMIDE-IMIDE)S BASED ON 4,4'-[1,4(OR 1,3)-PHENYLENEBIS(ISOPROPYLIDENE-1,4-PHENYLENEOXY)]DIANILINE

The diamines 4,4'-[1,4(or 1,3)-phenylenebis(isopropylidene-1,4-phenyleneoxy)] dianiline (p-3 and m-3) were synthesized in two steps from the condensation of 4,4'-[1,4(or 1,3)phenylenediisopropylidene] diphenol (p-1 and m-1) and p-chloronitrobenzene in the presence of K2CO3 in N,N-dimethylformamide (DMF), giving the corresponding bis(4-nitrophenoxy) compounds, followed by reduction with the hydrazine/Pd-C system. A series of aromatic polyamides, aliphatic-aromatic polyamides, and poly(amide-imide)s were prepared by the direct polycondensation of the diamines with aromatic or aliphatic dicarboxylic acids and phthalimide unit-bearing dicarboxylic acids in N-methyl-2-pyrrolidone (NMP) using triphenyl phosphite and pyridine as condensing agents. In addition, two series of polyamides were prepared from terephthalic acid or isophthalic acid and aromatic diamines with isopropylidene and/or ether linking groups between the phenylene units, and the structure-property relationships of these polyamides were studied. Almost all the resultant polymers were amorphous in nature and could be solution-cast into transparent, tough, and flexible films. Most of the polymers exhibited moderately high thermal stability. Thus, they are considered as new candidates for processable high-performance polymeric materials.