Perfluorinated bisphenol

Two crosslinkable perfluorinated bisphenol A polymeric derivatives having nonlinear optical chromophores containing thiophene have been prepared. Both crosslinked polymers had higher Tg s and greater mechanical stability than their noncrosslinked analogues and were used as light-emitting diodes. 

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). 

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. 

Laboratory and epidemiological data suggest that various polychlorinated biphenyls, dioxins, flame retardants, pesticides (e.g., DDT), perfluorinated chemicals, phthalates, bisphenols, and ultraviolet filters may inhibit thyroid function through a variety of mechanisms [31-33]. 

Within the realm of BAM2G membranes, a series of partially fluorinated bisphenol A-type poly(arylether) sulfones were synthesized. As mentioned above, these materials initially exhibited acceptable, useful service-life performance, but were unable to provide more than 500 h of continuous running time. This led to the decision that a perfluorinated backbone would be most beneficial in achieving fuel cell longevity in performance and efficiency. Therefore, the a, 3,p-trifluorostyrene monomer was chosen as the most suitable platform on which to build BAM3G polymers [98]. The BAM3G has demonstrated over 100,000 h of cumulative performance in a wide variety of Ballard fuel cell hardware. The BAM3G membranes have... 

Aldol condensation of acetone catalyzed by perfluorinated sulfonic resins has been studied, but conversions are in general low as the reaction is under thermodynamic control [130]. A very efficient preparation of bisphenol A, however, with 99.7% selectivity towards the p,p isomer (23), could be developed using a polymer partly neutralized (30%) with 2-mercaptoethylamine (Scheme 10.8) [131]. Other... 

Time of flight static secondary ion mass spectroscopy (SSIMS) has been applied to perfluorinated polymers, polystyrene, polyacylacrylates (including poly cyclo-hexylmethacrylate, polybenzyl methacrylate, polyphenyl methacrylate, poly n-hexyl methacrylate, poly n-butyl methacrylate, polymethylmethacrylate, poly n-propyl methacrylate, polyisopropyl methacrylate and poly secbutyl methacrylate). Blends of polystyrene and polyvinyl chloride, bisphenol A and polystyrene, polycarbonate and polystyrene and tetramethyl bisphenol A and polycarbonate have also been studied by this technique. 

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