Biphenyltetracarboxylic dianhydride BPDA

This one step method has been used for the syntheses of rodlike polyimides, for example with 3,3,4,4/-biphenyltetracarboxylic dianhydride (BPDA) and 2,2 -bisBrinuoromcthyll- T-diaminobiphcnyl (PFMB).109... 

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) ... 

Monitoring the imidisation of a polyamic acid made from 3,3 ,4,4 -biphenyltetracarboxylic dianhydride (BPDA) and p-phenylenediamine (PDA) was accomplished using IR spectroscopy (115). 

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. 

Typical Procedure for the Preparation of Polyimides Containing Pendant N-Acylated Caprolactam Moieties. After BAPBC (1.5(XX) g, 3.4772 mmol) was polymerized with 33 4,4 -biphenyltetracarboxylic dianhydride (BPDA) (1.0229 g, 3.4772 mmol) in N-methyl-2-pyirolidinone (NMP) (14.5 ml) at 22 C for 12 h, pyridine (0.633 g, 8.(X) mmol) and acetic anhydride (0.816 g, 8.00 mmol) were added. After stirring for another 24 h at 22°C under N2, the solution was dilut with NMP and slowly added to vigorously stirred ethanol. The polymer that precipitated was... 

Miscibility of PI blends of different structures was reported by Hasegawa et al. [1991] using charge-transfer fluorescence spectra, dynamic mechanical analysis, and phase-contrast microscopy. These blends were BPDA/PDA PI with PMDA/PDA and PMDA/ODA PFs (BPDA = biphenyltetracarboxylic dianhydride PDA = p-phenylene diamine ODA = oxydianUine PMDA = pyromellitic dianhydride). Two patents issued virtually simultaneously noting the utility of miscible PI blends for gas separating membranes [Burgoyne et al., 1991 Kohn et al., 1991]. 

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