Bisphenol preparation

Bisphenol Preparation. The mesogenic bisphenols were produced in a manner similar to that of Stilz and Pommer (14). First, tetraethyl-p-xylylenediphosphonate was produced in a reaction between a,al-dibromo-p-xylene and triethyl phosphite in xylene. The diphosphonate was then reacted with an excess of the appropriately-substituted p-hydroxybenzaldehyde. The preparative details and analytical results for the four monomers were given earlier (Mates, T.E. Ober, C.K. sL Polvm. Sci. Lett., to be published). 

TetrabromobisphenoIA. Tetrabromobisphenol A [79-94-7] (TBBPA) is the largest volume bromiaated flame retardant. TBBPA is prepared by bromination of bisphenol A under a variety of conditions. When the bromination is carried out ia methanol, methyl bromide [74-80-9] is produced as a coproduct (37). If hydrogen peroxide is used to oxidize the hydrogen bromide [10035-10-6] HBr, produced back to bromine, methyl bromide is not coproduced (38). TBBPA is used both as an additive and as a reactive flame retardant. It is used as an additive primarily ia ABS systems, la ABS, TBBPA is probably the largest volume flame retardant used, and because of its relatively low cost is the most cost-effective flame retardant. In ABS it provides high flow and good impact properties. These benefits come at the expense of distortion temperature under load (DTUL) (39). DTUL is a measure of the use temperature of a polymer. TBBPA is more uv stable than decabrom and uv stable ABS resias based oa TBBPA are produced commercially. 

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). 

Bisa.codyl, 4,4 -(2-PyridyLmethylene)bisphenol diacetate [603-50-9] (Dulcolax) (9) is a white to off-white crystalline powder ia which particles of 50 p.m dia predominate. It is very soluble ia water, freely soluble ia chloroform and alcohol, soluble ia methanol and ben2ene, and slightly soluble ia diethyl ether. Bisacodyl may be prepared from 2-pyridine-carboxaldehyde by condensation with phenol and the aid of a dehydrant such as sulfuric acid. The resulting 4,4 -(pyridyLmethylene)diphenol is esterified by treatment with acetic anhydride and anhydrous sodium acetate. Crystallisation is from ethanol. 

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). 

Polycarbonates are prepared commercially by two processes Schotten-Baumaim reaction of phosgene (qv) and an aromatic diol in an amine-cataly2ed interfacial condensation reaction or via base-cataly2ed transesterification of a bisphenol with a monomeric carbonate. Important products are also based on polycarbonate in blends with other materials, copolymers, branched resins, flame-retardant compositions, foams (qv), and other materials (see Flame retardants). Polycarbonate is produced globally by several companies. Total manufacture is over 1 million tons aimuaHy. Polycarbonate is also the object of academic research studies, owing to its widespread utiUty and unusual properties. Interest in polycarbonates has steadily increased since 1984. Over 4500 pubflcations and over 9000 patents have appeared on polycarbonate. Japan has issued 5654 polycarbonate patents since 1984 Europe, 1348 United States, 777 Germany, 623 France, 30 and other countries, 231. 

Cyclic aryl ether ketones have been prepared from l,2-bis(4- uoroben2oyl)ben2ene and bisphenols under pseudo high dilution conditions. These materials undergo ring-opening polymeri2ation in the presence of an anionic catalyst (87). 

Aromatic polysulfites can be produced if bisphenols, eg, bisphenol A, are heated with diphenyl sulfite in the presence of lithium hydride (112). Halosulfates and Halosulfites. A general method for the preparation of alkyl halosulfates and halosulfites is the treatment of the alcohol with sulfuryl or thionyl chloride at low temperatures while passing an inert gas through the mixture to remove hydrogen chloride (113). 

The most common commercial polycarbonate [24936-68-3] is prepared from 2,2-bis (4-hydroxyphenyl)propane, that is, bisphenol A [80-05-7] and has the general stmcture ... 

It is prepared from the polycondensation of the disodium salt of bisphenol A and 4,4-dichlorodiphenyl sulfone in a polar aprotic solvent such as dimethyl sulfoxide (26). 

Polyether Imides. Polyether imides (PEIs) are amorphous, high performance thermoplastic polymers that have been in use since 1982. The first commercial polyether imides were the Ultem series developed by the General Electric Co. The first, Ultem 1000 [61128-24-3] is prepared from phthahc anhydride, bisphenol A, and meta-phenylenediamine and has the following stmcture ... 

These materials have the general structure shown in Figure 20.11 and are prepared by reaction of bisphenol A with iso- and/or terephthalic acid and a carbonate group donor (e.g. phosgene or diphenyl carbonate). 

Aliphatic polycarbonates have few characteristics which make them potentially valuable materials but study of various aromatic polycarbonates is instructive even if not of immediate commercial significance. Although bisphenol A polycarbonates still show the best all-round properties other carbonic ester polymers have been prepared which are outstandingly good in one or two specific properties. For example, some materials have better heat resistance, some have better resistance to hydrolysis, some have greater solvent resistance whilst others are less permeable to gases. 

Although most of the macrocycles that contain phosphorus or arsenic which have thus far been prepared, are primarily transition metals binders, two compounds have been prepared which are essentially crown ethers containing phosphorus. Kudrya, Shtepanek and Kirsanovhave prepared two compounds which are essentially polyoxygen macrocycles but which contain one or two methylphosphonic acid esters as part of the ring. These two macrocycles are shown below as 7d and 17 and are both prepared by the reaction of 2,2 [oxybis(ethyleneoxy)] bisphenolate with methylphosphonic dichloride in a mixture of acetonitrile and benzene. The crystalline monomer 16) and dimer 17) were isolated in 17% and 11% yields respectively as indicated in Eq. (6.13). 

A different variety of copolymer has been prepared by Gramain and Frere who treated 1,10-diaza-l 8-crown-6 with the bisglycidyl ether of bisphenol A. The reaction was conducted at reflux in a mixture of THF and methanol. The polymer, illustrated in Eq. (6.24) was formed 83% yield. The polymer was appparently quite stable, surviving aging tests conducted over a two-year period. 

Recently, the pyrazole group containing bisphenols have been synthesized from activated aromatic dihalides and 3,5-bis (4-hydroxy phenyl)-4-phenyl pyrazole or 3,5-bis(4-hydroxy phenyl)-1,4-diphenyl pyrazole. A novel synthesis of imido aryl containing bisphenols has been reported [32]. N-substituted l,4-bis(4-hydroxy phenyl)-2,3-naphthalimides were prepared from phenolphthalein and copolymerized with aromatic sulfone or ketone difluorides to obtain the poly(imidoaryl ether) sulfones/ ketones. 

Polyphosphonates are well-known flame-retardant materials [110] and are generally prepared by melt [111,112], interfacial [113-115] and solution polycondensation methods [116]. A typical example of synthesis is the polycondensation of bifunctional organophosphorus compounds, such as dichlorophenylphosphine oxide, with bisphenols [117,118]. 

Polyphosphates are also an important class of organophosphorus polymers. In addition to their flame-retardant characteristics, they possess attractive plasticizing properties and can be used as polymeric additives to other polymers [123-128]. In general, polyphosphates can be prepared by interfacial [119,129], melt [130], or solution polycondensation [131,132a,b]. Kricheldorf and Koziel [133] prepared polyphosphates from silylated bisphenols. 

Phenothiophosphine ring-containing polyamides and polyesters were also prepared by the polycondensation of 2,8-bischloroformyl-lO-phenylphenothiophos-phine 5,5, 10-trioxide with aromatic diamines such as 4,4 -diaminodiphenyl ether and 4,4 -diaminodiphenyl-methane, and bisphenols such as 4,4 -dihydroxybiphe-nyl and 4,4 -dihydroxydiphenylmethane, respectively [159]. These polymers are soluble in polar aprotic solvents and also exhibit good heat and fire resistance. Phosphorus containing high performance polymers are shown in Table 6. 

C—S—C) in the main chain. The new polyethers prepared either by new heteroarylene activated or by aromatic activated systems have good melt processability. The thermal stability and glass transition temperature of bisphenol-A based new polymers are shown in Table 10. 

Polyether sulfones can be prepared by the reaction of the sodium or potassium salt of bisphenol A and 4,4-dichlorodiphenyl sulfone. Bisphenol A acts as a nucleophile in the presence of the deactivated aromatic ring of the dichlorophenylsulfone. The reaction may also be catalyzed with Friedel-Crafts catalysts the dichlorophenyl sulfone acts as an electrophile ... 

Lexan, a polycarbonate prepared from diphenyl carbonate and bisphenol A, is another commercially valuable polyester. Lexan has an unusually high impact strength, making it valuable for use in telephones, bicycle safety helmets, and laptop computer cases. 

Epoxy adhesives are prepared in two steps. S -2 reaction of the disodium salt of bisphenol A with cpichlorohydrin forms a "prepolymer," which is then "cured" by treatment with a triaminc such as I-I2NCH2CH2NHCH2CH2NEI2-... 

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