Synthesis and characterization of BTDA‐based polyamide‐imides

Abstract

SynopsisA series of thermally-stable, tough, linear polyimides containing amide linkages were prepared. These materials have potential as high temperature films and coatings as well as matrix resins in graphite reinforced structures. The new polyamide-hides were prepared by reacting a group of isomers of diaminobenzanilide (DABA) with 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA) to form the polyamide-acid with subsequent thermal conversion to the polyamide-imide (PAI). Four polymers were synthesized from unsubstituted amide diamines and two others from N-substituted amide diamines. The properties of these polyamide-hides were compared to those of the polyimide of benzophenonetetracarboxylic dianhydride/3,3'-diaminobenzophenone (LARC-TPI) because their structures are similar, except for the presence of the more flexible amide linkages. These polymers exhibited high inherent viscosities and glass transition temperatures. They were made into tough, flexible films which showed good thermal stability and good resistance to organic solvents. Mechanical properties of the PA1 films were better than those of LARC-TPI. Films of the 4,4'-isomer polyamide-bide exhibited an exceptionally high modulus and toughness during impact evaluation.

Initial evaluation of novel polyamide-imides and their copolymers as adhesives

“…The incorporation of the amide linkage into the polyimide backbone did not appear to degrade the thermo-oxidative stability of these polymers. TGA of the PAI films indicated that they exhibited similar thermal stabilities to that of LARC-TPI [ 1 ] .…”

“…The synthesis of the amide diamines has been reported previously [ 1 ], and involves the reaction of a nitrobenzoyl chloride with a nitroaniline to form a dinitrobenzanilide. These dinitrobenzanilides are then catalytically reduced to form the desired diaminobenzanilide.…”

“…A series of thermally stable, tough, linear polyimides containing amide linkages have been prepared at NASA Langley Research Center [ 1 ] . These aromatic polyamide-imides (PAI), because of intermolecular hydrogen bonding and chain stiffness, possess high thermal stability.…”

Synthesis and Properties of Organosoluble Poly(amide-imide-imide)s Based on Tetraimide-Dicarboxylic Acid Condensed from 4,4’-(Hexafluoroisopropylidene)diphthalic Anhydride, 1,4-Bis(4-aminophenoxy)benzene, and Trimellitic Anhydride, and Various Aromatic Diamines

“…20 The second route goes through the imide-forming reaction, with amidecontaining monomer serving as a medium; for example, amide-containing diamine is polycondensed with dianhydride to provide the poly(amide amic acid), which is then dehydrated to obtain PAI. 21,22 The third route goes through the amide-forming reaction from imidecontaining monomers such as dicarboxylic acids or diamines. Imide-containing dicarboxylic acids usually come from the thermal imidization of diamines and TMA, [23][24][25] from the condensation of dicarboxylic anhydride and amino acids, [26][27][28] or from the dehydration of aromatic amino acids and TMA.…”

Novel heat resistant nanostructure poly(amide–imide)s containing new TMA-based diacid via conventional polycondensation reaction in an ionic green medium: synthesis, morphology, and thermal properties

“…The first method involves the amide-imide forming reaction, by which trimellitic anhydride (TMA) react with diisocyanate [21]. The second rout goes through the polycondensation between amide-containing diamine with dianhydride to produce PAI [22,23]. The last rout goes through the amide-forming reaction from imide-containing monomers such as dicarboxylic acids or diamines [24][25][26].…”