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

Abstract

ABSTRACT:A novel tetraimide-dicarboxylic acid (I) was synthesized starting from the ring-opening addition of 4,4 -(hexafluoroisopropylidene)diphthalic anhydride (6FDA), 1,4-bis(4-aminophenoxy)benzene (TPEQ), and trimellitic anhydride (TMA) at a 1:2:2 molar ratio in N-methyl-2-pyrrolidone (NMP), followed by azeotropic condensation to the diacid I. A series of poly(amide-imide-imide)s (PAIIs) with inherent viscosities of 1.0-1.3 dL g −1 was prepared from the diacid I with various aromatic diamines by direct polycondensation. Most of the PAIIs were readily soluble in a variety of amide polar solvents, and even in less polar m-cresol and pyridine. Solvent-cast films had a tensile strength ranging from 80 to 101 MPa, elongation at break from 10 to 17%, and initial modulus from 2.0 to 2.4 GPa, and all of them exhibited clear yield points on their stress-strain curves. The glass transition temperature of these PAIIs was recorded at 260-289 • C. They had 10% weight loss at a temperature above 520 • C in air or nitrogen atmosphere.KEY WORDS Tetraimide-Dicarboxylic Acid / Organosoluble / Poly(amide-imide-imide)s / Direct Polycondensation / Aromatic polyimides are well-known as high performance polymeric materials due to their excellent thermal stability, electric insulation property, and chemical resistance. [1][2][3][4][5][6][7] Polyimides are mainly used in the aerospace and electronic industries in the forms of films and moldings. However, the applications are limited due to their high softening or melting temperatures and their insoluble nature in most organic solvents. To overcome these drawbacks, the modifications of polyimide structure are often be used, for example the introduction of flexible linkages, non-symmetrical structure, or bulky substituents into polymer backbones. [8][9][10][11][12][13] The other method is by using copolymerization to synthesize copolymers to improve processability, such as poly(amide-imide) (PAI). 14,15 Aromatic PAIs possess desirable characteristics with merits of both polyamides and polyimides such as high thermal stability and good mechanical properties as well as easy processability. These polymers can be synthesized from various aromatic monomers containing dianhydride, diamine, dicarboxylic acid, amino acid, or anhydride-acid by polycondensation. PAIs usually have been synthesized through several main routes. The first route goes through the amide-imide-forming reaction, by which trimellitic anhydride (TMA) reacts either with diisocyanate to produce PAI [16][17][18][19] or with thionyl chloride to synthesize TMA-chloride before the † To whom correspondence should be addressed.latter and diamine can produce PAI. 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 a...

Low-Tg polyimides containing multiple ether linkages and cyano pendants

“…16 4,4′-(1,4-Phenylenedioxy)diphthalic anhydride (HQODA) and 4,4′-[(hexafluoroisopropylidene)bis( p -phenyleneoxy)]diphthalic anhydride (6FODA) were prepared by a reported procedure. 33 –35 4,4′-Oxydiphthalic anhydride (ODA) was purchased from Sinopharm Chemical Reagent Co. Ltd (Shanghai, China) and dried at 120°C for 12 h before use. 2,5-Dihydroxybiphenyl (Sigma-Aldrich, Shanghai, China), 1-chloro-4-nitrobenzene (Sinopharm Chemical Reagent Co. Ltd, Shanghai, China), 2-chloro-5-nitrobenzonitrile (Shanghai Darui Fine Chemical Co. Ltd, Shanghai, China), 4-nitrophthalonitrile (Aladdin Chemistry Co. Ltd, Shanghai, China), 4,4′-(hexafluoroisopropylidene)diphenol (Aladdin Chemistry Co. Ltd, Shanghai, China), 4,4′-dihydroxydiphenyl ether (Aladdin Chemistry Co. Ltd, Shanghai, China), potassium hydroxide (Sinopharm Chemical Reagent Co. Ltd, Shanghai, China), acetic anhydride (Beijing Chemical Reagent, China), glacial acetic acid (Sinopharm Chemical Reagent Co. Ltd, Shanghai, China), N , N -dimethylacetamide (DMAc; Tianjin Chemical Reagent, China), N , N -dimethylformamide (DMF; Tianjin Chemical Reagent, China), potassium carbonate (K 2 CO 3 ; Beijing Chemical Reagent, China.…”