Polyamides incorporating phosphine oxide groups: IV. Aromatic-aliphatic polymers

Six novel polyamides, incorporating triarylphosphine oxide groups and aliph atic bridging units, have been prepared. Of these, three were synthesised b y a direct melt condensation reaction of bis(4-carboxyphenyl)phenylphosphin e oxide (p-BCPPO) with a series of aliphatic diamines. A phosphorylation po lycondensation method was used to prepare three polymers from bis[4-(3-amin ophenoxy)phenyl] phenylphosphine oxide (m-BAPPO) and a series of aliphatic dicarboxylic acids. The thermal properties of all polyamides were investiga ted by differential scanning calorimetry and thermogravimetric analysis. Si gnificantly different results were obtained for the two series. Glass trans ition temperatures (T-g) in the 215-235 degrees C range, together with good thermooxidative stabilities (5% weight loss occurring at > 420 degrees C) and high char yields upon prolonged heating at 700 degrees C (40-44%) were observed for the polyamides synthesised from m-BAPPO. The polymers prepared from p-BCPPO incorporated longer aliphatic bridging units and, consequentl y, demonstrated lower T-g values (184-205 degrees C) and reduced thermooxid ative stability (5% weight loss occurring at > 370 degrees C). Good solubil ity in aprotic polar solvents was observed for all polyamides. Additionally , those with -(CH2)(5)- and -(CH2)(6)- units within the polymer backbone we re partially soluble (0.1-1.0%) in several common organic solvents, such as chloroform and acetone. (C) 1998 Elsevier Science Ltd. All rights reserved .