Hexafluoropropane dianhydride

Often the substitution of fluorine atoms for hydrogen atoms in a polymer chain markedly increases the thermal stabiUty of the base polymer this is tme for polyimides. A typical fluorinated polyimide is prepared from the reaction of 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride and 2,2-bis-(4-amino phenyl)hexafluoropropane according to the following reaction (36) ... 

There are only two inexpensive dianhydrides 3,3,4,4,-benzophcnonctctracarbox-ylic dianhydride (BTDA) and pyromellitic dianhydride (PMDA). Some other commercially available dianhydrides were used, like 3,3, 4,4 -biphenyltetracarboxylic dianhydride (BPDA), 2,2,-bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydride (6FDA), oxydiphthalic anhydride (ODPA), and 3,3/,4,4/-diphenylsulfonetetracarboxylic dianhydride (DSDA) (Fig. 5.29). Many other dianhydrides are reported in the literature (Fig. 5.30) ... 

Zeolite/polymer mixed-matrix membranes prepared from crosslinked polymers and surface-modified zeolite particles offered both outstanding separation properties and swelling resistance for some gas and vapor separations such as purification of natural gas. Hillock and coworkers reported that crosslinked mixed-matrix membranes prepared from modified SSZ-13 zeolite and 1,3-propane diol crosslinked polyimide (6FDA-DAM-DABA) synthesized from 2,2 -feis-(3,4-dicarboxyphenyl)hexafluoropropane dianhydride, p-dimethylaminobenzylamine-and 3,5-diaminobenzoic acid displayed high CO2/CH4 selectivities of up to 47 Barrer and CO2 permeabilities of up to 89 Barrer under mixed gas testing conditions [71]. Additionally, these crosslinked mixed-matrix membranes were resistant to CO2 plasticization up to 450 psia (3100kPa). 

Models Based on 2,2- Bis(3,4-Carboxyphenyl)Hexafluoropropane Dianhydride (6FDA)... 

MATERIALS. The 4,4 -oxidiphthalic anhydride (ODPA) was recrystallized from anisole and sublimed at 200°-210 C/1 mm prior to use (m.p. 224°C). The 2,2-bis(3,4-dicarboxphenyl) hexafluoropropane dianhydride (6F) was obtained from American Hoechst and recrystallized from toluene/acetic anhydride (m.p. 

The aromatic diamines and dianhydrides used in the preparation of the polyamic acid resins and the diamic acid additives are listed in Figure 1. The 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA), 4,4 -oxydianiline (4,4 -ODA), and 3,3 -diaminodiphenylsulfone (3,3 -DDS02) were obtained from commercial sources. The remaining monomers were obtained as experimental materials as follows (1) 4,4 -bis(3,4-dicarboxyphenoxy) diphenylsulfide dianhydride (BDSDA) from General Electric Corporate R D Center (2) 4,4 -oxydiphthalic anhydride (ODPA) from Occidental Chemical Corporation (3) 2,2-bis[4(4-aminophenoxy)phenyl]hexafluoropropane (4-BDAF) from Ethyl Corporation and (4) 2,2-bis[4(3-aminophenoxy)phenyl]hexafluoropropane (3-BDAF) and 3,3 -oxydianiline (3,3 -ODA) from Mitsui Toatsu, Inc. 

Poly [2,2 -bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride-co-4,4 -diamino-3,3 -dimethylbiphenyl] 424... 

Xu and Coleman studied 6FDA (2,2 -bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride)-pMDA (pyromellitic dianhydride) polyimide films irradiated by an ion beam [84]. A beam of 140 keV N ions with a low-current density was used, and three irradiation fluences (2 x 10 cm , 1 x 10 cm , and 5 x 10 cm ) were chosen. It was reported that even a small dose altered the microstructure of the surface layer. The AFM analysis of those films showed that low-fluence irradiation induced microvoids in the surface layer of the polymer, and high-fluence irradiation resulted... 

Kawakami et al. prepared dense and asymmetric membranes from 2,2 -bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) and bis[4-(4-aminophen-oxy)phenyl]sulfone (APPS) by solvent evaporation (dense) and by the dry-wet phase inversion technique [47]. The surface morphology was studied by AFM. They reported that the solvent evaporation method adopted for the preparation of the dense membrane influenced the formation of nodules, while the dry-wet process in which solvent/nonsolvent exchange was involved determined the roughness of the skin layer. 

FTIR and fluorescence spectroscopy are used to monitor the imidisation of a polyamic acid made from 3,3, 4,4 -biphenyltetracarboxylic dianhydride (BPDA) and p-phenylenediamine (PDA), and fluorescence spectroscopy is used to monitor the imidisation of a polyamic acid made from 2,2-bis(3,4-dicarboxyphenyl hexafluoropropane dianhydride (6FDA) and p-phenylene diamine. A film of the polyamic acid made from BPDA and PDA is heated in a nitrogen atmosphere for one hour at 75 deg.C, and the thermal treatment is repeated at each of the temperatures from 100 to 400 deg.C in 25 deg.C increments between successive thermal treatments. After each treatment, the fluorescence and the excitation spectra of the film are taken at an excitation wavelength of 460 nm and a fluorescence wavelength of 550 nm, respectively. Extended abstract only. 

All anhydride and amine compounds were of the highest quality commercially available. Aniline (AN) was distilled imder reduced pressure phthalic anhydride (PA) was sublimed and stored under anhydrous conditions. High-quality NMP (BASF) was stored over molecular sieves. All other reagents were used as received from commercial sources as follows 4-fluoroaniline (4-FA) (99%, Aldrich Chemical Co.), 3-fluorophthalic anhydride (3-FPA) (Fluorochem Ltd.), 2,2- bis(3,4-carboxyphenyl)hexafluoropropane dianhydride (6FDA) (monomer grade, Hoechst) 2,2-bis(4-aminophenyl)hexafluoropropane (6FDM) (99%, Chriskev Co., Inc.), l,l -bis(3,4-carboxyphenyl) sulfone dianhydride (SDA) (99%, Chriskev Co., Inc ), 1,1 -oxydiphthalic anhydride (ODPA) (Occidental Chemical Co.), (4-aminophenyl)phenyl ether and 4-aminophenylben-zophenone (Aldrich Chemical Co.). 

C.P. Yang, Y.-Y. Su, M.-Y. Hsu, Organo-soluble and hghtly-colored fluorinated polyimides based on 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl] hexafluoropropane dianhydride and aromatic Bis(ether amine)s bearing pendent trifluoro-methyl groups, Polym. J. 38 (2006) 132-144. 

Bis [4-(3-Ethynylphenyl-N-phthalimide) ] hexafluoropropane (7) The bisimide was prepared from the reaction of 2,2-bis(3, 4 -dicarboxy-phenyl)hexafluoropropane dianhydride with two moles of 3-aminophenyl-acetylene in glacial acetic acid. Purification by chromatographing on silica gel provided the material with a mp 185-186 C, reported mp 180-186 C. 

The aromatic polyimide system was prepared by the reaction of the diaminoethynylbiphenyl moiety with 2,2 -bis[U-(3, -dicarboxyphenoxy)phenyl] hexafluoropropane dianhydride. The polymerization was carried out in N,N-dimethylacetamide to form the polyamicacid and then cyclohydrated to the imide by addition of acetic anhydride. Although several anhydrides were condensed with the diamine, the anhydride containing the hexafluoropropane group provided the lowest Tg with the rod-like imide system. 

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