Bisphenol fluorine

From the preparative point of view it should be noted that Hay et al. prepared polyformals for more than 15 bisphenols. Fluorine substituted polyformals were later contributed by a Japanese research group [47]. Those authors observed the... 

Pubhcations have described the use of HFPO to prepare acyl fluorides (53), fluoroketones (54), fluorinated heterocycles (55), as well as serving as a source of difluorocarbene for the synthesis of numerous cycHc and acycHc compounds (56). The isomerization of HFPO to hexafluoroacetone by hydrogen fluoride has been used as part of a one-pot synthesis of bisphenol AF (57). HFPO has been used as the starting material for the preparation of optically active perfluorinated acids (58). The nmr spectmm of HFPO is given in Reference 59. The molecular stmcture of HFPO has been deterrnined by gas-phase electron diffraction (13). 

Decafluorobiphenyl [434-90-2] C F C F (mol wt, 334.1 mp, 68°C bp, 206°C), can be prepared by I Jllmann coupling of bromo- [344-04-7] chloro- [344-07-0] or iodopentafluorobenzene [827-15-6] with copper. This product shows good thermal stabiHty decafluorobiphenyl was recovered unchanged after 1 h below 575°C (270). Decafluorobiphenyl-based derivatives exhibit greater oxidative stabiHty than similar hydrocarbon compounds (271). Therm ally stable poly(fluorinated aryl ether) oligomers prepared from decafluorobiphenyl and bisphenols show low dielectric constant and moisture absorption which are attractive for electronic appHcations (272). 

Numerous avenues to produce these materials have been explored (128—138). The synthesis of two new fluorinated bicycHc monomers and the use of these monomers to prepare fluorinated epoxies with improved physical properties and a reduced surface energy have been reported (139,140). The monomers have been polymerized with the diglycidyl ether of bisphenol A, and the thermal and mechanical properties of the resin have been characterized. The resulting polymer was stable up to 380°C (10% weight loss by tga). 

Although the synthesis of fluorinated polyarylethers by the reaction between decafluorobiphenyl with bisphenols had previously been described by others [18,19], those polymers were not fully characterized and no particular utility was ascribed to them. 

The para-fluorine atoms on highly fluorinated aromatic compounds such as hexafluorobenzene or decafluorobiphenyl are activated and thus can go through aromatic nucleophilic substitution with bisphenols in an aprotic solvent at low temperatures (<80°C).121 123... 

The fluorine content, density, critical surface energy, glass transitions, thermal expansion coefficient above and below the glass transition, and 300°C isothermal thermogravimetric stabilities of the fluoromethylene cyanate ester resin system with n = 3, 4, 6, 8, 10 are summarized Table 2.2. Also included for the purpose of comparison are the corresponding data for the aromatic cyanate ester resin based on the dicyanate of 6F bisphenol A (AroCy F, Ciba Geigy). 

Synthesis and Properties of Fluorine-Containing Aromatic Condensation Polymers Obtained from Bisphenol AF and Its Derivatives... 

Research on fluorine-containing condensation polymers is rather limited compared to that on fluorine-containing addition polymers. This fact is attributed to the difficulty in synthesis and the high cost of fluorine-containing condensation monomers. Recently, 2,2-bis(4-hydroxyhpenyl)-1,1,1,3,3,3-hexafluoropropane (Bisphenol AF) with a hexafluoroisopropylidene unit, HOC6H4C(CF3)2-C6H4OH, was produced commercially from hexafluoroacetone and phenol, and now Bisphenol AF and its derivatives are available as condensation monomers. 

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 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 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. 

Fluorine-containing copoly(formats (8) are synthesized in a similar manner by reacting the mixtures ofBisphenol AF (1) and Bisphenol A (4) with DCM (Scheme 4).12... 

Resistance to acids is improved by the introduction of fluorine atoms. Bisphenol A poly(formal) (6) decomposes rapidly with significant coloration in strong acids, whereas Bisphenol AF poly(formal) (7) is stable in concentrated sulfuric acid.12... 

A contact angle by water is 86° for Bisphenol A poly(formal) (6), is increased to 93° by the introduction of 28 mol% of hexafluoroisopropylidene unit, and then becomes almost constant irrespective of fluorine content.12 As... 

Four poly(ether ketone)s obtained from 2,2-bis[4-(4-fluorobenzoyl)-phenyl]-1,1,1,3,3,3-hexafluoropropane (9) or 2,2-bis[4-(4-fluorobenzoyl)-phenyl]propane (10) with Bisphenol AF (1) or Bisphenol A (4) are all soluble in chloroform, benzene, THF, and aprotic polar solvents such as DMF, DMAc, and NMP.15 Poly(ether ketone) from 9 and 1, which has the highest fluorine content, dissolves easily in ethyl acetate. 

Recently the synthesis and characterization of novel fluorinated poly(aryl ether)s containing perfluorophenylene moieties " " was also reported. These fluorinated polyethers were prepared by reaction of decafluorobiphenyl with bisphenols. These polymers exhibit low dielectric constants, low moisture absorption, and excellent thermal and mechanical properties. Tough, transparent films of the polymers were prepared by solution-casting or compression-molding. The fluorinated poly(aryl ether)s containing perfluorophenylene moieties are good candidates for use as coatings in microelectronics applications. 

A number of HFIP-derived polyethers are known which exhibit good mechanical, thermal, and electrical properties (112,113). Aromatic polyethers have been synthesized from bisphenol A (R = H) or AF (R = F) and fluorinated aromatics (Ar = perfluorophenyl, perfluorobiphenyl, or... 

---