3,3 ,4,4 -Biphenyl dianhydride

In Pis based on the dianhydrides 4,4 -BTDA and 3,3, 4,4 -biphenyl dianhydride (4,4 -BPDA), those that are terminated with 4-(l-phenylethynyl) 1,8-naphthalic anhydride (PENA) show superior properties in comparison to PEPA. Oligomers derived from PENA can be cured at lower temperatures and the corresponding cured polymers exhibit a better hydrolytic stability than those of PEPA. 

Cyclobutanetetracarboxylic dianhydride 4,4 -Hexafluoroisopropylidene diphthalic dianhydride 3,3, 4,4 -Biphenyl dianhydride... 

Some diamines and dianhydrides with a flexible linkage in their structure have been listed in Table 2. The combination of those dianhydrides and diamines, and also the combination of some of them with conventional rigid monomers like benzenediamines, benzidine, pyromellitic dianhydride or biphenyl-dianhydride, offer a major possibility of different structures with a wide spectrum of properties, particularly concerning solubility and meltability [48-56]. 

Disilanes have been used in stoichiometric amounts as reductants in the palladium-catalyzed coupling of electron deficient aryl chlorides. By this procedure, trimellitic anhydride acid chloride (70) was converted to the high temperature polymer precursor biphenyl dianhydride (71) in 85% yield with concomitant decarbonylation (see Scheme 35 [128]). 

Miscibility, Structure, and Property of Poly (biphenyl dianhydride perfluoromethylbenzidine)—Poly(ether imide) Molecular Composites... 

Miscibility of segmented rigid-rod polyimide (PI), viz., biphenyl dianhydride perfluoromethylbenzidine (BPDA-PFMB), and flexible polyether imide (PEI) molecular composites was established by differential scanning calorimetry. The composite films of BPDA-PFMB/PEI were drawn at elevated temperatures above their glass transitions. Tensile moduli of the films were evaluated as a function of composition and draw ratio. Molecular orientations of polyimide were determined by birefringence and wide-angle X-ray diffraction. The crystal orientation behavior of the 80/20 BPDA-PFMB/PEI was analyzed in the framework of the affine deformation model. 

Further improvements in polymerized monomeric reactants are achieved by end capping the phenylethynyl-terminated imide with resin precursor agents such as 4-phenylethynyl phthatic anhydride (PEPA) or biphenyl dianhydride-based polyimides, which offer toughness and flexibility up to 569°E (316°C) in carbon fiber nanocomposites. 

Liou, G. S. et al. Preparation and properties of new soluble aromatic polyimides from 2,2 -bis(3,4-dicarboxyphenoxy) biphenyl dianhydride and aromatic diamines. J. Polym. Sci. Part A,Polym. Chem. 36(12), 2021-2027 (1998). 

All these dianhydrides should have a very high reactivity, because of the lower values of lumo for both the dianhydride and the monoamide. In fact, hexafluoroisopropyliden 4,4 -diphthalic anhydride should be only slightly less reactive than benzophenone tetracarboxylic dianhydride, and 2,3,6,7-naphthalene tetracarboxylic dianhydride should be very similar to biphenyl dianhydride. But if the reaction is controlled by the monoamide, as we have postulated, the most reactive dianhydride should be 1,4,5,8-naphthalene tetracarboxylic dianhydride, because lumo is almost the same than for pyromellitic dianhydride, but lumo monoamide is lower than lumo monoamide of the pyromellitic (—2.33 versus — 2.18eV). 

Poly(bisphenyl tetraoarboxylio dianhydride-oo-phenylene diamine) Biphenyl dianhydride-/ -phenyIene- diamine copoljmier 293 19 22-0 (5,5 -Biisobenzoftiran)-1, 1, 3,3 -tetrone, polymer with 1,4-benzenediamine R (C I6H606 CaHgNz).,... 

Y.-H. Kim, H.-S. Kim and S.-K. Kwon. Synthesis and characterisation of highly soluble and oxygen permeable new polyimides based on twisted biphenyl dianhydride and spi-rofluorene diamine. Macromolecules 38, 2005, 7950-7956. 

Biaryl derivatives bearing reactive groups have become increasingly important in industry. Uses for this class of compounds are constantly being developed in the production of high performance polymers. Materials such as 3,3, 4,4 -biphenyl-tetracarboxylic dianhydride 1 and 4,4 -biphenol 2 are monomers employed in the manufacture of high performance polyimides or polyesters. Applications for this family of molecules have also been found both in the dye industry and in the pharmaceutical industry. 

Dibenzothiophene acts as a 7r-electron donor and readily forms complexes with known electron acceptors. In such cases the electronic spectrum of a solution of the two compounds shows a new absorption band, usually in the visible region. The order of donor strengths of several o,o -bridged biphenyls has been estimated from their respective charge-transfer spectra and found to be carbazole > fluorene > dibenzothiophene >dibenzofuran. Dibenzothiophene forms complexes with tetracy-anoethylene, various polynitro derivatives of fluorenone, > naphthalene-1,4,5,8-tetracarboxylic acid dianhydride, and tetra-methylmic acid. ... 

Recently a convenient method for the synthesis of maleimide-terminated imide oligomers has been described (38). Aromatic diamine, biphenyl tetracar-boxylic dianhydride and maleic anhydride are reacted in DMAc/Xylene at 50 °C to form the amic acid oligomer which was subsequently cyclodehydrated by refluxing in the presence of pyridine as a catalyst. Water is removed azeo-tropically over a period of three hours. The maleimide terminated imide oligomer is isolated by precipitation in water or a non-solvent. The molar ratio of the monomers can be varied widely to tailor the molecular weight and... 

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