Bisphenol A BPA

Bisphenol A is manufactured by a reaction between phenol and acetone, the two products from the cumene hydroperoxide rearrangement. The temperature of the reaction is maintained at 50 °C for about 8-12 hr. A sluny 

The student should develop the mechanism of this reaction using the following stepwise information (1) protonation of the carbonyl (2) electrophilic attack on the aromatic ring (3) rearomatization by proton loss (4) another protonation, but then loss of a water molecule and (5) electrophilic attack and rearomatization. 

The major uses of BPA are in the production of polycarbonate resins (63%) and epoxy resins (27%). Polycarbonates have major outlets in automotive parts, compact discs, eyeglasses, and sheet and glazing applications, and have caused bisphenol A consumption to more than double during the past decade. Epoxy resins are two-component adhesives for very strong bonding. Miscellaneous uses include flame retardants (mostly tetrabromobisphenol A) and other polymer manufacture. Polycarbonate grade bisphenol A is 99% p,p isomer. The epoxy grade is 95% p,p. The p,p and o,p isomers can be separated by a combination of distillation and crystallization. 

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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). 

Epoxy Resins. Epoxy resins (qv) are used to cross-link other resins with amine, hydroxyl, and carboxyHc acid (or anhydride) groups. The epoxy group, properly called an oxkane, is a cycHc three-membered ether group. By far the most widely used epoxy resins in coatings are bisphenol A (BPA) (4,4 -(l-methylethyHdene)bisphenol) [80-05-7] epoxy resins. 

Diphenol/thiophenol is one of the most important polymer precursors for synthesis of poly(aryl ethers) or poly-(aryl sulfides) in displacement polymerizations. Commonly used bisphenols are 4,4 -isopropylidene diphenol or bisphenol-A (BPA) due to their low price and easy availability. Other commercial bisphenols have also been reported [7,24,25]. Recently, synthesis of poly(aryl ethers) by the reaction of new bisphenol monomers with activated aromatic dihalides has been reported. The structures of the polymer precursors are described in Table 2. Poly(aryl ether phenylquinoxalines) have been synthesized by Connell et al. [26], by the reaction of bisphenols containing a preformed quinoxaline ring with... 

As an example of suspected endocrine disruptors (EDs), studies of the estrogenic action of bisphenol A (BPA) have been in progress in medical, physiological, and biological fields. In this situation, physicochemical approaches are required to get the structural information of BPA trapped in biomembranes. Most recently, we have determined the site and the orientation of BPA trapped in phospholipid vesicles by NMR, using the HCS rule [47]. In particular, we have succeeded in monitoring the NMR spectral changes of phospholipid vesicles, which are induced by the BPA delivery. 

Paper mill whitewaters and effluents are rich in bisphenol A (BPA), which is used in great quantities for the production of epoxy resins and polycarbonate plastics. Its presence in effluents has been reported as a result of its use in the manufacture of thermal paper or due to migration from plastic containers at the high water temperatures of whitewaters [35]. This compound is preferably analysed by GC-MS. The levels encountered in paper mill effluents are between 28 and 72 pg/L [36,37]. Another study revealed levels up to 226 pg/L [33]. Special in vitro test systems and animal experiments have demonstrated a weak oestrogenicity for BPA. Since aquatic wildlife could be endangered by paper mill waste discharges at the concentration that BPA is found, its survey in paper mill effluents should be taken into consideration. 

From the wide variety of emerging pollutants of industrial origin that could be considered here, bisphenol A (BPA) and phthalate esters (PE) are of especial relevance not only because of the high volumes produced and their widespread use, but also because of their demonstrated toxicity, particularly as endocrine disrupters. Both of them have been included in the final report of the European Commission toward the establishment of a priority list of endocrine disrupter chemicals, EDCs [3], and have been rated as of high risk of exposure for human and wildlife populations. Because of their structural characteristics these compounds cannot be included in any of the groups described above, so they will be described in this section (see Fig. 10). 

Bisphenols. See also Bisphenol A (BPA) aromatic polycarbonates derived from, 19 806-808t... 

Boxing dental wax, 8 299 specification, 8 300t Box-type mixer-settler, 10 774 Boyer, Herbert, 11 11 BPA diacetate, transesterification of, 19 816. See also Bisphenol A (BPA)... 

Bisphenol A (BPA) (Figure 14.1a) is a starting substance utilized in the manufacture of most types of epoxy resins, which are then crosslinked and used to coat food cans. Another application of BPA is in the manufacture of plastic materials, in particular polycarbonates. BPA serves also as an antioxidant or stabilizing material for many types of plastics, e.g., polyvinyl chloride (PVC). 

Bisphenol-A (BPA) or 2,2-bis(4-hydroxyphenyl)propane is one of the highest volume chemicals produced worldwide, with a production volume of approximately 3.8 million tons in 2006 [199]. BPA is mainly used as monomer in the production of polycarbonate and epoxy resins. Polycarbonate is a transparent polymer with a high impact resistance which can be used in different consumer goods such as reusable drinking bottles and food containers. Epoxy resins on the other hand are used as inner coating of food and drink cans. Release and exposure of... 

Another large molecule of potential interest would be anions derived from Bisphenolacetone (Figure 8) S)mthesis (Eqn 7), notable reactions to produce polycarbonate (Eqn. 8) or epoxy resins (Eqn. 9). As reviewed recently elsewhere [45]. Bisphenol A (BPA), the s)mthesis of which is shown (Eqn. 7), is a component in the s)mthesis of polycarbonate plastics and epoxy resins (Eqn. 8, 9) that have a variety of significant uses. 

While the EPA used to list DEHA as a toxic chemical, for some reason it no longer does. But we re not convinced. We want more concrete evidence that a chemical formerly labeled toxic won t harm us when it leaches out of plastic, especially when we re pregnant or breastfeeding. Exercising caution when it comes to plastic makes even more sense when you take into account another study done by Dr. Patricia Hunt in the April 2003 issue of Current Biology, which reported that exposure to bisphenol-A (BPA) causes a chromosomal abnormality in the oocytes, or egg cells, of female mice. Polycarbonate plastic ( 7), used for everything from glasses to bowls, is manufactured with bisphenol-A. 

Table 2.13. Concentrations of alkylphenols (APs) and bisphenol A (BPA) in various environmental media in Korea... 

A wide variety of xenobiotics can act as EDC (Fig. 8.5), bisphenol-A (BPA) and nonylphenol (NP) being the most extensively studied. They are widely dispersed in the environment, but they can mainly be found in wastewater effluents. BPA is used as a raw material for the production of polycarbonates and epoxy resins, and is present in the discharges of BPA producing factories, from installations that incorporate BPA into plastic, from leaching of plastic wastes and landfill sites. 

Bisphenols. Bisphenol-A (BPA) (Dow [Parabis-A] and Union Carbide [bisphenol-HP] ), as received, generally is of adequate purity. Predrying at 120°C./1 mm. was carried out to remove surface moisture. 

Bisphenol A (BPA) mimics the effects of estrogens, which can lead to health effects at high enough concentrations. BPA is used in polycarbonate bottles (see Section 21-16) and in some of the plastic linings of canned foods. Several countries have banned the sale of polycarbonate baby bottles and the use of canned food liners containing BPA because of their concerns that the polymers might hydrolyze and leach free BPA into the food orwaterinthe container. 

Application A highly efficient process to produce bisphenol-A (BPA) from phenol and acetone. The BPA product is suitable for high-quality polycarbonate (PC) and epoxy resins applications, including optical-media grade PC. 

This phenomenon may be also important for all natural estrogens and endocrine-disrupting chemicals (EDCs) which are weak acids, such as 17 -estra-diol, estriol, ethynylestradiol, diethylstilbestrol, nonylphenol, octylphenol, bisphenol-A (BPA), tetrabromobisphenol-A (TBBA), hydroxy polychlorinated biphenyls, and other compounds with hydroxylated aromatic rings. 

Environmental chemicals such as p-nonylphenol (NP), 4-ferf.-octylphenol (OP), 4-ferf.-pentylphenol (TPP), bisphenol-A (BPA), tetrabromobisphenol-A (TBBA), butylbenzylphthalate (BBP), di- -butylphthalate (DBP), butylated hydroxyanisole (BHA), p-chloro-ra-cresol, p-chloro-o-cresol, ds-nonachlor, frans-nonachlor, and the herbicide alachlor [2-chloro-iV-(2,6-diethylphenyl)-N-(methoxymethyl) acetamide] have been discovered to be weakly estrogenic [128,129,137,138]. 

PTOP), p-nonylphenol (NP) and bisphenol A (BPA). The results showed the presence of PTOP in three samples in the range 2.2 to 37 p-g/g, NP in fifteen samples in the range 2.6 to 513 pg/g, and no PTBP or NP in any samples. Some specific migration experiments for NP were also carried out using water, 20% ethanol and n-heptane. The levels were found to vary from 0.004 to 1.519 pg/ml, with the higher results being obtained with the n-heptane. 

Polycarbonates are a class of thermoplastic polymers that are used in the plastic lenses of eyeglasses and in the shells of bicycle helmets. A polycarbonate is made from the reaction of bisphenol A (BPA) with phosgene (COCl2) ... 

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