4,4’- diphthalic

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). 

Of course, this re-equilibration behavior of two homopoly(amic acids) can be eliminated if one of the components does not exhibit this back reaction. Recombination of different fragments is not possible and stable polyimide precursor blends are accessable [119]. For example, combining a relatively flexible poly(amic acid), hexafluoroisopropylidene diphthalic anhydride (6F)/2,2-bis(4-aminophenoxy-4 -phenyl) propane (BDAF), with a rigid poly(amic alkyl ester), PMDA/p-phenylene diamine (PDA), produced microphase separated polyimide blends as can be interred by the persistence of the... 

Diphthalic Acid Peroxide or Diphthaloyl Peroxide. See Bis(phthalic acid)-peroxide h Voi 2, p B156-.L... 

Diphthalic acid peroxide see Bis (phthalic acid)-peroxide 2 B1S6... 

By using hexafluoroisopropylidene diphthalic tetraacid dimethyl ester (HFDE) instead of BTDE and a mixture of meta- and para-phenylene (mPDA.pPDA) instead of MDA a new generation of more stable nadic resins has been developed (Fig. 34) [106]. Table 5 summarizes the Tgs and the thermo-oxidative properties of these materials as a function of their molecular weight. 

Fig. 38. Linear polyimide and bisnadimide obtained with isophthaloyl diphthalic anhydride and raefa-phenylenediamine...

Hexafluoroisopropylidene dianiline was dissolved in DMAc and then treated with the dropwise addition of 4,4 -hexafluoroisopropylidene diphthalic anhydride at ambient temperature. The 20 to 25 wt% solution was next stirred 6 to 8 hours until high molecular polyamic acids were formed. The mixture was treated with a large excess of triethylamine and acetic anhydride and dehydrated by heating to 50°C for 2 to 3 hours and at 100°C to 110° C for 10 to 20 minutes then cooled to ambient temperature. The viscous solution was slowly poured into methanol, and the precipitate was homogenized in a blender. It was then filtered and washed several times with fresh methanol. The material was dried for 12 hours at ambient temperature and 24 hours under vacuum at 250°C, and the product was isolated. 

Selective polyimide membranes, (I), for helium, carbon dioxide, and oxygen were previously prepared by the author [1] by condensing 4,4 -(hexafluoro-isopropylidene) diphthalic anhydride with a 3 2 ratio of 2,4,6-trimethyl-1,3-phenylene diamine and diamino benzoic acid, respectively. 

Soluble polyimide prepared by reaction of 4,4 -hexanuoroisopropylidene diphthalic anhydride (6F) with 3,5-diaminobenzoic acid. 

FIGURE 9.2 Dependence of hydrocarbon solubility coefbcient in glassy polymers on hydrocarbon Lennard-Jones force constant, ejk, at T — 323 K and pressure of 2 atm (6FDA-TrMPD is polyimide based on dianhydride of 4,4 -hexafluoroisopropylydene diphthalic acid and 2,4,6-trimethyl-l,3-phenylenediamine PPO is polyphenylene oxide). (From Tanaka, K., Taguchi, A., Flao, J., Kita, FI., Okamoto, K., J. Membr. Sci., 121, 197, 1996. With permission.)... 

Diphthalic Acid Peroxide or Diphthployl Peroxide. See Bls(phthalic acid)-peroxide b Vol 2, p Bi56iL... 

Crystd from water (20mL/g), the crystals being separated from the chilled soln by centrifugation, then washed with chilled EtOH (sol Ig in 10 mL of hot EtOH) and diethyl ether and dried under vac. It is sol in CHCI3 but insol in Et20. The carbinol was ppted from an aqueous soln of the HCl dye, using excess NaOH, then dissolved in HCl and recrystd from water as the chloride [UV and kinetics Turgeon and La Mer / Am Chem Soc 74 5988 7952]. The carbinol base has m 195 (needles from EtOH). The diphthalate (blue and turns red in H2O) crystallises from H2O, m 153-154 (dec 185-187 )[Chamberlain and Dull J Am Chem Soc 50 3089 7925]. 

From the same class of light sensitive and heat resistant polymers, poly[4,4 -hexafluoro-isopropylidene)-diphthalic anhydride-a/f-acridine yellow G], HCI is given as another example. The structure of this polymer is shown below ... 

Figure 13.4.2. Variation of weight % loss forpoly[4,4 -hexafluoro-isopropylidene)-diphthalic anhydride-alt-acridine yellow G] HCI in a TGA experiment at a heating rate of 10P C/min.

The TGA curve indicates a complex decomposition process. The Py-GC/MS result for poly[4,4 -hexafluoro-isopropylidene)-diphthalic anhydride-aff-acridine yellow G] HCI is given in Figure 13.4.3. This is a light sensitive polymer (X max. 273 nm) but also with high heat resistance, and the pyrolysis was performed at 850 C in He. Other conditions were kept similar to those for other examples previously described (see Table 4.2.2). The separation was done on a Carbowax column. The peak identification was done using MS spectral library searches only and is given in Table 13.4.4. 

Figure 13.4.3. Pyrogram from Py-GC/MS analysis of poly[4,4 -hexafluoro-isopropylidene)diphthalic anhydride-alt-acridine yellow G] HCI. Pyrolysis done on 0.4 mg material at 85(f C in He, with the separation on a Carbowax type column.

Finally, two Al-neutralized copolyimides from (4,4 -hexafluoroisopropylidene) diphthalic anhydride, (4,4 -hexafluoroisopropylidene) dianiline, and 3,5-diaminobenzoic acid exhibit a variety of aggregate shapes and sizes that have not been previously observed or even postulated. Scanning TEM shows Al-rich aggregates in both copolymers, but the aggregate size and shape distributions in the ionomer with a high ionic fraction are much more heterogenous than in the ionomer with a lower ionic fraction. This is despite... 

Soluble polyimide prepared by reaction of 4,4 -hexafluoroisopropylidene diphthalic anhydride (6F) with 3,5-diaminobenzoic acid. b Soluble polyimide prepared by reaction of (6F) with 1,5-diaminonaphthalene. c Soluble polyimide prepared by reaction of (6 F) with 1,4-diaminobenzene. d Poly(para-xylylene) Union Carbide Reg. trademark. e Dupont 100 CA-43. f Union Carbide Sulfone 47. 

MAJOR USES Manufacture of diphthalic anhydride, phthalic anhydride, phthalonitrile, benzoic acid, ethyl benzene, high performance polymers, plasitcizers, alkyd resins, glass reinforced polyesters, dyes, insecticides and motor fuels. 

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

Tricresyl phosphate, 45, 218 Triethanol amine, 79 Triethylamine, 309, 454, 458, 481 Triethyl phosphate, 265 Trifluoroacetic anyhdride, 486 Trifluoromethanesnlfonic add, 72, 189, 223, 242, 248 (4-(4 -Trifluoromethyl)phenoxyphenyl)hydroquinone, 210 4,4 -(Trifluoromethylphenylisopropylidene)diphenol, 183 4,4 -(2,2,2-Triflnoro-l-pentafluorophenylethylidene) diphthalic dianhydride, 477... 

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