Poly carbonization

Fig. 1. Stmcture of poly(carbon monofluoride). , carbon o, fluorine. The interstitial space is 0.66 nm.

Graphite fluoride continues to be of interest as a high temperature lubricant (6). Careful temperature control at 627 3° C results in the synthesis of poly(carbon monofluoride) [25136-85-0] (6). The compound remains stable in air to ca 600°C and is a superior lubricant under extreme conditions of high temperatures, heavy loads, and oxidising conditions (see Lubrication and lubricants). It can be used as an anode for high energy batteries (qv). 

Poly- propylene poly- ethylene CAB" ABSf PVC Saran Polyester glass 1 Epoxy glass phenolic asbestos Fluoro- carbons Chlorinated polyether (Penton) Poly- carbonate... 

In a recent work of Haneda et al. [26], ACPC was reacted with several poly-diols poly(ethylene adipate), poly(tetramethyleneadipate), poly(caprolactone), aliphatic poly(carbonate) to prepare various polyazoesters. 

The activation energy of thermolysis of the azo group was measured by DSC [14]. Type II MAIs, which are composed of various prepolymers such as aliphatic polyester, poly(caprolactone), and aliphatic poly (carbonate), showed almost the same activation energy irrespective of difference in prepolymer structure, suggesting that the neighboring group only affects the active site. 

Fig. 3. ESCA results on the surface segregation of the Polycarbonate homopolymer/Poly-carbonate-Polydimethylsiloxane segmented copolymer blends 1S0)...

As a review on poly(carbon monofluoride) has recently appeared (K1), our treatment here will be cursory,... 

Dining interaction at ambient temperature in a bomb to produce poly (carbon monofluoride), admission of fluorine beyond a pressure of 13.6 bar must be extremely slow and carefully controlled to avoid a violently exothermic explosion [1], Previously it had been shown that explosive interaction of carbon and fluorine was due to the formation and decomposition of the graphite intercalation compound, poly (carbon monofluoride) [2], Presence of mercury compounds prevents explosion during interaction of charcoal and fluorine [3], Reaction of surplus fluorine with graphite or carbon pellets was formerly used as a disposal method, but is no longer recommended. Violent reactions observed when an exhausted trap was opened usually involved external impact on the metal trap, prodding the trap contents to empty the trap, or possibly ingress of moist air... 

A fluorine-containing poly(carbonate) was first synthesized by Knunyants and co-workers from Bisphenol AF and phosgene.2 However, detailed properties of this polymer other than the softening temperature of 170°C have not been reported. 

It has been reported that high-molecular-weight poly(carbonate)s can be synthesized using A,A -carbonyldiimidazole as a condensing agent under mild conditions.4-5 However, the reagent is very sensitive to moisture and must be handled with extreme care. 

Bisphenol-AF-derived poly(carbonate) (2) has been synthesized by the two-phase transfer-catalyzed polycondensation of Bisphenol AF (1) with trichloromethyl chloroformate (TCF) in organic-solvent-aqueous-alkaline solution systems with a variety of quaternary ammonium salts at room temperature (Scheme l).6... 

When TBAB is used as a phase-transfer catalyst, sodium hydroxide as a base, and DCE as a solvent, both the molecular weight and yield of the poly(carbonate) are relatively high. Bisphenol AF-derived poly(carbonate) (2) having reduced viscosity of 0.35 dl/g is obtained in a 84% yield at ambient temperature under the... 

Table 9.1. Effects of Phase-Transfer Catalyst and Organic Solvent on the Yield and Reduced Viscosity of Bisphenol-AF-Derived Poly(Carbonate)6...

Table 9.2. Preparation of Fluorine-Containing Poly(Carbonate)s6...

It has been determined from X-ray diffraction measurements that polycarbonate containing Bisphenol AF moiety are all amorphous.6 The (Tg) of poly(carbonate)s increases with an increase in hexafluoroisopropylidene unit from 149°C for Bisphenol A poly(carbonate) (3) to 169°C for Bisphenol AF poly(carbonate) (2) (Table 9.3).6 Thermooxidative stability is also improved by the introduction of fluorine atoms into the isopropylidene units. The 10% weight-loss temperature (DT10) increases from 429 to 460°C and the residual weight (RW) at 500°C goes from 37 to 57% by perfluorination of the isopropylidene units. 

The solubility is generally improved by the introduction of fluorine atoms into aromatic condensation polymers. Poly(carbonate)s containing hexafluoroisopropylidene units are much more soluble than Bisphenol A poly(carbonate) (3). All of the hexafluoroisopropylidene-unit-containing poly(carbonate)s become soluble in acetone, ethyl acetate, chloroform, and dimethyl sulfoxide (DMSO) in addition to the solvents of Bisphenol A poly(carbonate) (3). Colorless, transparent, and flexible films are prepared from hexafluoroisopropylidene-unit-containing poly(carbonate)s by casting or pressing. 

The contact angle (0) by water at 25°C in air is 84° for Bisphenol A poly(carbonate) (3) film (Table 9.4).6 Introduction of 19% of Bisphenol AF unit increases the value of (0) to 90° and from that point it is almost constant irrespective of fluorine content. This abrupt increase in (0) is attributed to the migration and... 

The high refractive index of Bisphenol A poly(carbonate) (3) is decreased by the incorporation of the Bisphenol AF moiety. The refractive index of Bisphenol A poly(carbonate) (3) is 1.585,9 whereas that of Bisphenol AF poly(carbonate)s (2) is 1.426. Poly(carbonate)s containing a small amount of Bisphenol AF moiety can be used as sheaths of optical fibers of Bisphenol A poly(carbonate) (3). 

The tensile strength and tensile modulus decrease and the elongation increases by the introduction of fluorine atoms into isopropylidene units of Bisphenol A poly(carbonate) (3),6 i.e., poly(carbonate) becomes more flexible by the introduction ofhexafluoroisopropylidene units. The increased flexibility is attributed to the weaker intermolecular interaction induced by fluorine atoms. 

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