Bisphenol-A carbonate

Synthesis of Bisphenol-A Carbonate-Siloxane Segmented Copolymers152>... 

FIGURE 5 Molecular structures of poly(Bisphenol A carbonate) and poly(Bisphenol A iminocarbonate). The poly(iminocarbonates) are, in a formal sense, derived from polycarbonates by replacement of the carbonyl oxygen by an imino group. 

Figure 2. Molecular structures of poly(Bisphenol A carbonate) and poly(Bisphenol A iminocarbonate).

Montaudo and co-workers have used direct pyrolysis mass spectrometry (DPMS) to analyse the high-temperature (>500°C) pyrolysis compounds evolved from several condensation polymers, including poly(bisphenol-A-carbonate) [69], poly(ether sulfone) (PES) and poly(phenylene oxide) (PPO) [72] and poly(phenylene sulfide) (PPS) [73]. Additionally, in order to obtain data on the involatile charred residue formed during the isothermal pyrolysis process, the pyrolysis residue was subjected to aminolysis, and then the aminolyzed residue analysed using fast atom bombardment (FAB) MS. During the DPMS measurements, EI-MS scans were made every 3 s continuously over the mass range 10-1,000 Da with an interscan time of 3 s. 

As an example of the form of the information that may be derived from a pyrolysis-MS, Figure 26 [69] shows the structure of the polycarbonate (PC) and the EI-MS spectra of pyrolysis compounds obtained by DPMS of poly(bisphenol-A-carbonate) at three different probe temperatures corresponding to the three TIC (total ion current) maxima shown in Figure 27(b) Figure 27 compares the MS-TIC curve with those obtained from thermogravimetry. (The TIC trace is the sum of the relative abundances of all the ions in each mass spectrum plotted against the time (or number of scans) in a data collection sequence [70].)... 

Figure 26 Structure of PC and El mass spectra of pyrolysis compounds obtained by DPMS of poly(bisphenol-A-carbonate) at probe temperatures of (a) 380°C, (b) 500°C and (c) 550°C. Reprinted with permission from Puglisi et al. [69]. Copyright 1999, American Chemical Society.

Figure 15.1. MALDI spectrum of a polycarbonate sample along with peak assignment. In the inset, an expansion of the spectral region from 3.0 up to 3.7 kDa is shown. (Reproduced from Puglisi, C. et al., 1999. Analysis of Poly(bisphenol A Carbonate) by Size Exclusion Chromatography/Matrix-Assisted Laser Desorption/lonization. I. End Group and Molar Mass Determination. Rapid Communications in Mass Spectrometry, 13 2260-2267. With permission of John Wiley Sons, Inc.)...

J. A. Talla, D. Zhang, S. A. Curran, Electrical transport measurements of highly conductive nitrogen-doped multiwalled carbon nanotubes/poly(bisphenol A carbonate) composites, Journal of Materials Research, vol. 22, pp. 2854-2859, 2011. 

Usually poly (bisphenol - A carbonate, commercially - lexan) is used as a polymer matrix. 

The blend of poly(bisphenol A carbonate)-(poly(caprolactone) PC-PCL is particularly unusual in that both polymers are capable of crystallization and FT-IR has been used to study the state of order in these blends as a function of the method of preparation 254,255). In this case, PCL is a macromolecular plasticizer for PC. The PCL becomes progressively less crystalline as the concentration of PC increases. PC is amorphous if the blend is cast from methylene chloride but semicrystalline if cast from tetrahydrofuran. When PC in the pure form is exposed to acetone, it will not crystallize, but in the blend, exposure of acetone causes the PC to crystallize which emphasizes the additional mobility of the PC in the blend. 

Carr, S. H., Geil, P. H., Baer, E. The development of spherulites from structural units in glassy poly(bisphenol-A-carbonate). J. Macromol. Sci.-Phys. B2,13-28 (1968). 

A knowledge of the chemistry of bisphenol-A oligomer carbonate synthesis is useful in the interpretation of GPC data. Bisphenol-A carbonate oligomers can be prepared by reaction of bisphenol-A with phosgene in the presence of an acid acceptor. The reaction can be conducted interfacially (6), in homogeneous pyridine solution (7), or by merely passing phosgene into an alkaline solution of bisphenol-A (8). The chemical reactions that occur in each of these systems are complicated and consist of multiple and competitive reactions. 

The interfacial synthesis of bisphenol-A carbonate oligomers is conducted by passing phosgene into an agitated, two-phase mixture of a water-insoluble organic solvent and an alkaline solution of bisphenol-A. Reactions 1-4 shown on p. 260 illustrate some of the reactions believed to occur in the interfacial system. 

Interfacial Syntheses of Bisphenol-A Carbonate Oligomers. Oligomers that were prepared interfacially were made in a 5000-ml, three-necked-baffled flask equipped with a water condenser and a Dry Ice condenser. Cooling was provided by an ice bath around the reactor. 

Syntheses of Bisphenol-A Carbonate Oligomers in Aqueous Caustic. Oligomers made by the aqueous caustic method were made in an apparatus identical with that used in the interfacial method experimental conditions were similar. Methylene chloride, though, was not added to the reaction mixture. The product precipitated on formation and was isolated by filtration. 

Syntheses of Bisphenol-A Carbonate Oligomers in Homogeneous Pyridine. Oligomers made by the pyridine method were prepared in the same apparatus except that drying tubes were added where necessary. It was also necessary to use carefully dried solvents since the undesirable side reaction with water converts chlorocarbonic acid to hydrochloric acid and carbon dioxide, thus upsetting the reaction stoichiometry. 

Analysis of Bisphenol-A Carbonate Oligomers for Phenolic Hydroxyl. 

Analysis of Bisphenol-A Carbonate Oligomers for Chloroformate Chlorine. Chloroformate chlorine end groups were determined by a modified Volhard procedure in which the bischloroformate first reacts with aqueous pyridine to convert chloroformate to chloride ion. The chloride ion is extracted into water and titrated by the Volhard procedure. 

Table I. Molecular-Weight Data on Interfacially Prepared Bisphenol-A Carbonate Oligomers...

Table III. CPC Data on Bisphenol-A Carbonate Oligomers Prepared in Pyridine...

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