Bisphenol A polymers

Bisphenol A-polycarbonate does not undergo a photo-Fries 

None of these products contribute towards the initiation of photooxidation of the polymer other than having some u.v. antioxidant action. On long-wavelength irradiation (365 nm) photoinitiation occurs via impurity chromophore whereas with light of wavelengths shorter than 300 nm direct excitation of the diphenylcarbonate unit occurs. 

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The polycarbonates which were used in these experiments had the following molecular weights (determined ebulliometrically) bisphenol I polymer, 20,700 bisphenol II polymer, 54,000 bisphenol A polymer, 28,200. 

When the additive consisted of an Aroclor (a chlorinated biphenyl or terphenyl), a poly(styrene glycol), or an abietic acid derivative, the tensile moduli of the films increased as the concentration of additive was increased to about 30%. In two films (from the bisphenol I and bisphenol A polymers), the modulus increased as the concentration of a chlorinated terphenyl increased even to 40%. Instead of becoming more flexible, as would be expected, the films became stiffen Most of these additives, incidentally, were viscous or very viscous oils. The effect of two Aroclors on the tensile moduli is shown in Figure 1. 

Li, X., Environmental stress cracking resistance of a new copolymer of bisphenol-A, Polym. Degrad. Stab. 2005, 90, 44-52. 

Other types of polycarbonates have also been made using a very different approach from that involving bisphenol A and related compounds. For example, the reaction between phosgene and allyl alcohol (CH2=CHCH2OH) produces a monomer with carbon-carbon double bonds at both ends of the molecule that can be used for polymerization. Interestingly enough, the polycarbonate produced by this process has very different physical properties from the traditional bisphenol A polymer. The allyl polymer is a clear, transparent, flexible plastic whose primary use is in the production of eyeglass lenses. 

Shaikh, A.G., Sivaram, S., Puglisi, C., Samperi, R, and Montaudo, G., Poly(aryl-enecarbonate)s oligomers by carbonate interchange reaction of dimethyl carbonate with Bisphenol-A, Polymer Bulletin, 32, 427, 1994. 

Solvent resistance was measured in 22 solvent systems, in 18 of these, the bisphenol A polymer and TCBF copolycarbonates behaved similarly. In 3 of them, viz., carbon tetrachloride, acetic acid, and acetonitrile, the TCBF copolyc urbonates were definitely better. In only one case, namely that of ethyl acetate, was bisphenol A polycarbonate superior. 

Iyer, S., Schiraldi, D.A. Role of specific interactions and solubility in the reinforcement of bisphenol-A polymers with polyhedral oligomeric silsesquioxanes. Macromolecules 40, 4942-4952 (2007)... 

Hou, S. S. Chung, Y. P. Chan, C. K. Kup, C. P. Function and performance of silicone copolymer. Part IV. Curing behavior and characterization of epoxy-siloxane copolymers blended with diglycidyl ether of bisphenol-A. Polymer, 2000, 41(9), 3263. Arends, C. B. Polymer Toughening, New-York, Marcel Dekker 1996. 

Some polymer materials which exhibit reversible redox activities respond to the pH of the test solution. Bisphenol-A polymer containing benzoquinonyl and hydroquinonyl groups not only shows electrochemical activities but also demonstrates a change in its conductance when changing the pH of the surrounding media. The conductance of polybisphenol-A (PBPA) is attributed to both ionic and... 

Fig. 23. Representative protecting groups for phenolic and carboxylic acid-based systems, (a) The polymer-based protecting groups are fisted in order of increasing activation energy for acid-catalyzed deprotection, (b) Acid-labile monomeric dissolution inhibitors, a bifunctional system based on protected bisphenol A. (c) Another system that combines the function of dissolution inhibitor and PAG in a single unit.

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. 

Miscellaneous Applications. Ben2otrifluoride derivatives have been incorporated into polymers for different appHcations. 2,4-Dichloroben2otrifluoride or 2,3,5,6-tetrafluoroben2otrifluoride [651-80-9] have been condensed with bisphenol A [80-05-7] to give ben2otrifluoride aryl ether semipermeable gas membranes (336,337). 3,5-Diaminoben2otrifluoride [368-53-6] and aromatic dianhydrides form polyimide resins for high temperature composites (qv) and adhesives (qv), as well as in the electronics industry (338,339). 

A polyester backbone with two HFIP groups (12F aromatic polyester of 12F-APE) was derived by the polycondensation of the diacid chloride of 6FDCA with bisphenol AF or bisphenol A under phase-transfer conditions (120). These polymers show complete solubkity in THF, chloroform, ben2ene, DMAC, DMF, and NMP, and form clear, colorless, tough films the inherent viscosity in chloroform at 25°C is 0.8 dL/g. A thermal stabkity of 501°C (10% weight loss in N2) was observed. 

The first HFIP-based polycarbonate was synthesi2ed from bisphenol AF with a nonfluorkiated aromatic diol (bisphenol A) and phosgene (121,122). Incorporation of about 2—6% of bisphenol AF and bisphenol A polycarbonate improved the dimensional stabkity and heat-distortion properties over bisphenol A homopolycarbonate. Later developments in this area concern the flame-retardant properties of these polymers (123,124). 

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). 

Polysulfone. Polysulfone is a commercial polymer that is a product of bisphenol A and 1,1 -sulfonylbis (4-chlorobenzene) (see Polymers... 

Polycarbonates. Currently, all audio CDs (CD-AD), all CD-ROM, and the biggest fraction of substrate disks for WORM and EOD worldwide are manufactured from a modified bisphenol A—polycarbonate (BPA-PC) (3). In 1991, some 1.3 x 10 compact disks were produced, equivalent to an annual amount of about 35,000 t BPA-PC. WORM and EOD disks are manufactured mainly from BPA-PC for sizes of 5.25 in. and below, and glass for larger form factors (eg, 12 in.), partially also from BPA-PC, and in some cases from aluminum or from cross-linked polymers (epoxy resins) (190). 

Fig. 26. Qualitative compatison of substrate materials for optical disks (187) An = birefringence IS = impact strength BM = bending modulus HDT = heat distortion temperature Met = metallizability WA = water absorption Proc = processibility. The materials are bisphenol A—polycarbonate (BPA-PC), copolymer (20 80) of BPA-PC and trimethylcyclohexane—polycarbonate (TMC-PC), poly(methyl methacrylate) (PMMA), uv-curable cross-linked polymer (uv-DM), cycHc polyolefins (CPO), and, for comparison, glass.

Fig. 2. Molecular structures of selected photoconductive polymers with pendent groups (1) poly(A/-vinylcarba2ole) [25067-59-8] (PVK), (2) A/-polysiloxane carbazole, (3) bisphenol A polycarbonate [24936-68-3] (4) polystyrene [9003-53-6] (5) polyvin5i(l,2-/n7 j -bis(9H-carba2ol-9-yl)cyclobutane) [80218-52-6]...

Polycarbonates are an unusual and extremely useful class of polymers. The vast majority of polycarbonates are based on bisphenol A [80-05-7] (BPA) and sold under the trade names Lexan (GE), Makrolon (Bayer), CaUbre (Dow), and Panlite (Idemitsu). BPA polycarbonates [25037-45-0] having glass-transition temperatures in the range of 145—155°C, are widely regarded for optical clarity and exceptional impact resistance and ductiUty at room temperature and below. Other properties, such as modulus, dielectric strength, or tensile strength are comparable to other amorphous thermoplastics at similar temperatures below their respective glass-transition temperatures, T. Whereas below their Ts most amorphous polymers are stiff and britde, polycarbonates retain their ductiUty. 

Other minor raw materials are used for specific needs. Eumaric acid [110-17-8] the geometric isomer of maleic acid, is selected to maximize thermal or corrosion performance and is the sole acid esterified with bisphenol A diol derivatives to obtain optimum polymer performance. CycloaUphatics such as hydrogenated bisphenol A (HBPA) and cyclohexanedimethanol (CHDM) are used in selective formulations for electrical apphcations. TetrahydrophthaUc anhydride [85-43-8] (THPA) can be used to improve resiUence and impart useful air-drying properties to polyester resins intended for coating or lining apphcations. 

The first aromatic sulfone polymer produced commercially was introduced as Bakelite polysulfone but now is sold by Union Carbide under the trade name Udel. It is made by reaction of the disodium salt of bisphenol A (BPA) with 4,4 -dichIorodiphenyl sulfone in a mixed solvent of chlorobenzene and dimethyl sulfoxide (eq. 12). 

DMSO is an effective solvent for the polymerization as it affords good solubiUty for both the polymer and disodium bisphenol A [2444-90-8]. Typical polymerization temperatures for polysulfone are in the range 130—160°C. At temperatures below 130°C, the polymerization slows down considerably due to poor solubiUty of the disodium bisphenol A salt. 

Solvent for Displacement Reactions. As the most polar of the common aprotic solvents, DMSO is a favored solvent for displacement reactions because of its high dielectric constant and because anions are less solvated in it (87). Rates for these reactions are sometimes a thousand times faster in DMSO than in alcohols. Suitable nucleophiles include acetyUde ion, alkoxide ion, hydroxide ion, azide ion, carbanions, carboxylate ions, cyanide ion, hahde ions, mercaptide ions, phenoxide ions, nitrite ions, and thiocyanate ions (31). Rates of displacement by amides or amines are also greater in DMSO than in alcohol or aqueous solutions. Dimethyl sulfoxide is used as the reaction solvent in the manufacture of high performance, polyaryl ether polymers by reaction of bis(4,4 -chlorophenyl) sulfone with the disodium salts of dihydroxyphenols, eg, bisphenol A or 4,4 -sulfonylbisphenol (88). These and related reactions are made more economical by efficient recycling of DMSO (89). Nucleophilic displacement of activated aromatic nitro groups with aryloxy anion in DMSO is a versatile and useful reaction for the synthesis of aromatic ethers and polyethers (90). 

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