Synthesis and properties of polyamides and poly(amideimide)s based on 4,4′‐[1,4(or 1,3)‐phenylenebis(isopropylidene‐1,4‐phenyleneoxy)]dianiline

Abstract

AbstractThe 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.