Synthesis and properties of new organosoluble and alternating aromatic poly(ester‐amide‐imide)s with pendant phosphorus groups

Abstract

AbstractNew phosphorus‐containing aromatic diesteramines, 1,4‐bis(4‐aminobenzoyloxy)‐2‐(6‐oxido‐6H‐dibenz〈c,e〉〈1,2〉oxaphosphorin‐6‐yl)naphthalene (p‐3) and 1,4‐bis(3‐aminobenzoyloxy)‐2‐(6‐oxido‐6H‐dibenz〈c,e〉〈1,2〉oxaphosphorin‐6‐yl)naphthalene (m‐3), were synthesized by the reaction of 2‐(6‐oxido‐6H‐dibenz〈c,e〉〈1,2〉oxaphosphorin‐6‐yl)‐1,4‐naphthalenediol with 4‐nitrobenzoyl chloride and 3‐nitrobenzoyl chloride, respectively, followed by catalytic reduction. Two series of phosphorus‐containing aromatic poly(ester‐amide‐imide)s with inherent viscosities of 0.94–2.00 and 0.41–0.56 dL/g were prepared via low‐temperature solution polycondensation from p‐3 and m‐3, respectively, with three imide ring‐preformed diacid chlorides. All the poly(ester‐amide‐imide)s were amorphous and readily soluble in many organic solvents such as N,N‐dimethylacetamide (DMAc) and N‐methyl‐2‐pyrrolidone (NMP). Transparent, tough, and flexible films of these polymers were cast from DMAc or NMP solutions. Their casting films possessed a tensile strength range of 118–181 MPa, an elongation to break of 5–11%, and an initial modulus range of 2.41–4.46 GPa. They had useful levels of thermal stability associated with relatively high glass‐transition temperatures (264–286 °C) and 10% weight‐loss temperatures in excess of 450 °C in nitrogen or air. The limiting oxygen indices of these polymers were 41–46. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1786–1799, 2001