Synthesis and properties of novel polyimides derived from 2,2′,3,3′‐benzophenonetetracarboxylic dianhydride

Abstract

A new synthetic route to 2,2′,3,3′‐BTDA (where BTDA is benzophenonetetracarboxylic dianhydride), an isomer of 2,3′,3′,4′‐BTDA and 3,3′,4,4′‐BTDA, is described. Single‐crystal X‐ray diffraction analysis of 2,2′,3,3′‐BTDA has shown that this dianhydride has a bent and noncoplanar structure. The polymerizations of 2,2′,3,3′‐BTDA with 4,4′‐oxydianiline (ODA) and 4,4′‐bis(4‐aminophenoxy)benzene (TPEQ) have been investigated with a conventional two‐step process. A trend of cyclic oligomers forming in the reaction of 2,2′,3,3′‐BTDA and ODA has been found and characterized with IR, NMR, matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry, and elemental analyses. Films based on 2,2′,3,3′‐BTDA/TPEQ can only be obtained from corresponding polyimide (PI) solutions prepared by chemical imidization because those from their polyamic acids by thermal imidization are brittle. PIs from 2,2′,3,3′‐BTDA have lower inherent viscosities and worse thermal and mechanical properties than the corresponding 2,3′,3′,4′‐BTDA‐ and 3,3′,4,4′‐BTDA‐based PIs. PIs from 2,2′,3,3′‐BTDA and 2,3′,3′,4′‐BTDA are amorphous, whereas those from 3,3′,4,4′‐BTDA have some crystallinity, according to wide‐angle X‐ray diffraction. Furthermore, PIs from 2,2′,3,3′‐BTDA have better solubility, higher glass‐transition temperatures, and higher melt viscosity than those from 2,3′,3′,4′‐BTDA and 3,3′,4,4′‐BTDA. Model compounds have been prepared to explain the order of the glass‐transition temperatures found in the isomeric PI series. The isomer effects on the PI properties are discussed. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2130–2144, 2004

Synthesis and properties of polyimides from isomeric bis(dicarboxylphenylthio)diphenyl sulfone dianhydrides

“…Different structural modifications of the polymer backbone have been studied to reduce the chain interaction, such as the introduction of flexible links (O, S, CO, SO, CH 2 , etc.) to the main chains which disrupt the conjugation and increase the chain flexibility, the addition of bulky substituents which hinder the chain packing but do not affect the glass transition temperature [10], and the introduction of geometrically asymmetric units by altering catenation patterns of dianhydride which have attracted much attention recently [11][12][13][14][15][16][17][18][19][20][21]. Recently, the researchers in our lab have studied the preparation and properties of a series of polyimides based on isomeric dianhydrides, such as mellanophanic dianhydride (MPDA), biphenyltetracarboxylic acid dianhydride (BPDA), benzophenonetetracarboxylic acid dianhydride (BTDA), oxy(diphthalic anhydride) (ODPA), diphenylthioether dianhydride (TDPA) and 1,4-bis(dicarboxyphenoxy) benzene dianhydride (HQPDA), and found many interesting rules about them [16][17][18][19][20][21].…”

Synthesis and characterization of high performance poly(thioether imide)s via aromatic nucleophilic substitution reaction of isomeric AB-type monomers

“…What is more, the copolyimides PTIs (b-d) had slightly better solubility than the homopolyimides PTIs (a, e) in m-cresol and phenol. That was because unsymmetrical 3-and 4-substituted phthalimide unit disturbed the regularity of molecular chain, which reduced the intermolecular interaction and hindered molecular chain close stacking and, therefore, improved the solubility of isomeric PTIs [20][21][22][23][24][25][26].…”

“…Recently, our group has successfully synthesized series of isomeric polythioetherimides by the polycondensation of isomeric dianhydrides and diamines [18][19][20][21] or by aromatic nucleophilic substitution reactions of isomeric bis(chlorophthalimide)s with bisthiophenols [22][23][24][25]. Isomeric polyimides, which possess geometrically asymmetric and noncoplanar moieties, were found to be endowed with improved solubility, low melt viscosity, comparable thermal and mechanical properties [26].…”

Synthesis and thermal properties of polyimides containing azomethine linkage for processable high-performance engineering plastics

“…Many efforts have been pursued to design and synthesize new diamines and dianhydride monomers, thus to generate a wide range of polyimides with promising processability and solubility for various technological and industrial applications [15][16][17]. Polymers with a Schiff-base structure (polyazomethine) have been drawing the attention of researchers for more than 50 years.…”