Products
Products
Products
| HS Code | 788534 |
| Chemical Name | 4,4'-(propane-2,2-diyl)diphenol |
| Cas Number | 80-05-7 |
| Molecular Formula | C15H16O2 |
| Molar Mass | 228.29 g/mol |
| Appearance | White to light brown flakes or powder |
| Density | 1.20 g/cm³ at 20 °C |
| Melting Point | 158-159 °C |
| Boiling Point | 360.5 °C at 760 mmHg |
| Solubility In Water | 0.3 g/L at 20 °C |
| Pka | 9.6-10.2 |
| Flash Point | 227 °C (closed cup) |
| Vapor Pressure | 5.3 × 10⁻⁶ Pa at 25 °C |
As an accredited Bisphenol A factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Bisphenol A is packaged as white flakes in 25 kg polyethylene-lined bags, sealed for safe transport and storage. |
| Container Loading (20′ FCL) | Bisphenol A in 25kg bags loaded into a 20-foot FCL, palletized and secured, approximately 20 metric tons per container. |
| Shipping | Bisphenol A ships as a solid, typically in sealed bags, drums, or FIBCs, with sturdy packaging to prevent dust release. Avoid incompatible materials and foodstuffs. If transported as an environmentally hazardous substance, it may require UN 3077, Class 9 labeling, and hazmat documentation. Ensure proper ventilation and spill containment during transport. |
| Storage | Store Bisphenol A in a cool, dry, well-ventilated area, away from direct sunlight, heat, and moisture. Keep containers tightly closed and clearly labeled, isolated from strong oxidizers, acids, bases, and foodstuffs. Use compatible, corrosion-resistant materials. Ensure proper grounding against static discharge and maintain secondary containment to prevent spills or environmental release. |
| Shelf Life | Store in a cool, dry, well-ventilated area away from light and incompatible materials. Shelf life is typically 2–3 years. |
Industrial polycarbonate-grade bisphenol A entering a continuous interfacial phosgenation line is typically specified to a purity floor of 99.85%, free phenol below 0.10 wt%, iron below 0.3 mg/kg, sodium below 0.5 mg/kg, and APHA colour below 10; deviations above these thresholds shift the molecular weight distribution and generate quinonoid chromophores that standard methylene chloride washing cannot remove. In the aqueous alkaline phase, bisphenol A is converted to the disodium salt with sodium hydroxide at pH 10.0–11.0, and phosgene is introduced in dichloromethane at 25–40°C; the stoichiometric phosgene demand is 1.05–1.15 mol per mol bisphenol A, while p-tert-butylphenol at 0.5–2.0 mol% functions as a monofunctional chain stopper to control endgroup concentration. The resulting bisphenol A mass fraction in the polycarbonate repeat unit is 89.8 wt%, a monomer-to-polymer mass balance rather than an additive proportion. Process equipment includes a 1500 rpm agitated reactor with high-shear impeller, followed by water separation, acid wash, and steam precipitation; melt viscosity at 300°C lies between 200 and 800 Pa·s, requiring gear pumps and secondary finishing in a twin-screw devolatilizing extruder at L/D 32:1 to reduce residual methylene chloride below 10 mg/kg. Compliance for food-contact grades is established under FDA 21 CFR 177.1580 and EU Regulation 10/2011, with the bisphenol A specific migration limit of 0.05 mg/kg set by EU 2018/213; mechanical property verification follows ASTM D3935-20, and melt volume-flow rate is tested to ISO 1133-1:2022 at 300°C/1.2 kg. Terminal product types include automotive headlamp lenses, medical device housings, optical storage substrates, and water-contact components where residual monomer migration governs regulatory compliance.
On production-scale equipment, a continuous interfacial line with a 10 m³ reactor and 1500 rpm high-shear impeller is sensitive to phase inversion when the organic-to-aqueous volume ratio drops below 0.9:1; pH is maintained at 10.0–10.5 with sodium hydroxide dosing to avoid re-protonation of phenolate groups that slows phosgene uptake and broadens chain-length distribution. After steam precipitation, the wet flake is dried in a twin-screw devolatilizing extruder with L/D 32:1 at 240–260°C under 5–20 mbar vacuum until residual methylene chloride is below 10 mg/kg. Before injection molding or extrusion, pellets are dried in desiccant dryers at 120°C for 4 h when ambient relative humidity exceeds 60%; moisture above 0.02% hydrolyzes carbonate linkages at 270–300°C, producing silver streaks and reducing notched Izod impact below specification. Mold clamping force for a 1.2 kg automotive lens is typically 6000–8000 kN, with melt temperature capped at 320°C because thermal degradation accelerates above that threshold and the release of volatile phenolics creates surface defects.
Liquid bisphenol A diglycidyl ether is produced by charging bisphenol A into epichlorohydrin at a molar ratio of 1:8 to 1:12 bisphenol A to epichlorohydrin; the high epichlorohydrin excess drives the reaction toward the n=0 monomer and suppresses chain extension. Sodium hydroxide is added at 2.05–2.20 mol per mol bisphenol A in a 20–50% aqueous solution over 2–6 h at 65–75°C, maintaining pH above 10 in the aqueous phase; the reaction mass is then vacuum-distilled at 50–150 mbar to recover epichlorohydrin, and the organic phase is washed with water until sodium chloride is below 5 mg/kg. The resulting liquid resin has an epoxide equivalent weight of 182–192 g/eq when measured to ASTM D1652-11, and the bisphenol A residue constitutes approximately 66.4 wt% of the DGEBA molecule. Solid epoxy resins with epoxide equivalent weights between 800 and 2500 g/eq are then produced by advancement: liquid epoxy is reacted with additional bisphenol A at a molar ratio of about 0.3–0.5 mol bisphenol A per mol liquid epoxy in the presence of 0.05–0.2 wt% triphenylphosphine or ethyltriphenylphosphonium acetate at 150–170°C under nitrogen. The advancement reactor is a 5–10 m³ jacketed vessel with helical ribbon agitator because the melt viscosity rises beyond 30 Pa·s at 150°C; batch-to-batch variability in epoxide equivalent weight is typically controlled within ±5 g/eq by active catalyst quenching with triphenylphosphite. Compliance for can coatings and food-contact maintenance coatings falls under FDA 21 CFR 175.300; European Union requirements for BADGE migration are fixed at 9 mg/kg in EU 1895/2005, while free bisphenol A migration is limited to 0.05 mg/kg under EU 2018/213. Terminal product types include two-component ambient-cure protective coatings, wind turbine blade adhesives, filament-wound pressure vessels, and printed circuit board laminates.
Batch-to-batch variability in liquid resin is controlled by monitoring refractive index at 25°C between 1.570 and 1.575; a drift of 0.002 corresponds to an epoxide equivalent weight shift outside the 182–192 g/eq window. Water washing is a process bottleneck if the brine phase exceeds 80°C, causing gelatinous interfacial rag and sodium chloride retention above 5 mg/kg. Solid resin advancement is stopped by addition of triphenylphosphite at 0.2–0.5 wt% to quench the catalyst; otherwise the melt continues to build viscosity above 40 Pa·s and may gel in the discharge gear pump, particularly when the reactor wall temperature exceeds 175°C.
| Downstream segment | Standard/regulation | Test method/clause | Limit or condition |
|---|---|---|---|
| Polycarbonate | FDA 21 CFR 177.1580, EU 10/2011, EU 2018/213 | ASTM D3935-20, ISO 1133-1:2022 | Bisphenol A SML 0.05 mg/kg; MVR at 300°C/1.2 kg |
| Liquid epoxy | FDA 21 CFR 175.300, EU 1895/2005 | ASTM D1652-11, ISO 3001 | BADGE migration 9 mg/kg; EEW 182–192 g/eq |
| Solid epoxy | FDA 21 CFR 175.300 | ASTM D1652-11 | EEW 800–2500 g/eq; residual NaCl ≤5 mg/kg |
| Polysulfone | FDA 21 CFR 177.1655, ISO 10993-1 | ASTM D638-22, ASTM D256 | Feed moisture below 0.05%; Mw above 25,000 g/mol |
| Polyarylate | UL 94 V-0 | ASTM D1003-13, ISO 178:2019 | Transmittance above 85% at 3.2 mm |
| Tetrabromobisphenol A | RoHS 2011/65/EU, REACH 1907/2006 | UL 94 V-0 | Laminate bromine 18–21 wt% at 1.6 mm |
| Benzoxazine | IPC-4101 | ASTM D638-22, UL 94 V-0 | Flexural modulus above 3.5 GPa at 150°C |
Polysulfone is synthesized from bisphenol A and 4,4′-dichlorodiphenyl sulfone in a 1.00:1.00 molar ratio, with potassium carbonate charged at 1.05–1.10 mol per mol bisphenol A to generate the reactive bisphenolate in situ. The solvent blend, typically sulfolane with chlorobenzene as an azeotropic water carrier, is dehydrated at 140–160°C until water content falls below 0.05 wt%; residual water above this threshold inhibits nucleophilic substitution and limits number-average molecular weight below 25,000 g/mol. Condensation proceeds at 160–190°C for 4–8 h, after which methyl chloride is metered at 0.5–2.0 mol% to cap phenoxide endgroups and reduce uncontrolled molecular weight drift during finishing. The crude polymer is isolated by steam precipitation, washed to reduce residual sulfolane below 0.1 wt%, and dried at 150°C to below 0.05% moisture. Medical-grade polysulfone is tested under ISO 10993-1 for cytotoxic potential and under FDA 21 CFR 177.1655 for repeated food-contact use; mechanical lot release typically includes tensile strength to ASTM D638-22 and notched Izod impact to ASTM D256. Terminal product types are hollow-fiber hemodialysis membranes with wall thickness below 100 µm, reusable surgical instrument handles, aviation interior panels, and high-temperature electrical connectors. The operational incompatibility is with chlorinated solvents in downstream processing; residual methylene chloride above 50 mg/kg in the molding feed has been observed to induce microvoids in thin-wall membrane extrusion.
| Downstream segment | Reactant charging ratio | Process window | Critical boundary |
|---|---|---|---|
| Polycarbonate | Phosgene:Bisphenol A 1.05–1.15:1 | 25–40°C, pH 10–11 | Moisture below 0.02% before melt processing |
| Liquid epoxy | Epichlorohydrin:Bisphenol A 8–12:1 | 65–75°C, pH ≥10 | Residual NaCl below 5 mg/kg |
| Solid epoxy | Bisphenol A:Liquid epoxy 0.3–0.5 mol:1 | 150–170°C, nitrogen | Reactor wall below 175°C to avoid gelation |
| Polysulfone | Bisphenol A:DCDPS 1.00:1.00 | 160–190°C, anhydrous | Water below 0.05 wt% |
| Polyarylate | Bisphenol A:Aroyl dichlorides 1.00:1.00 | 5–25°C, pH 10–11 | Unreacted aroyl chloride below 50 mg/kg |
| Tetrabromobisphenol A | Bromine:Bisphenol A 4.0:1 | 20–40°C | Theoretical bromine 58.8 wt% |
| Benzoxazine | Bisphenol A:Aniline:Paraformaldehyde 1:2:4 | 85–110°C, azeotropic water removal | Cure exotherm onset near 180°C |
In polyarylate interfacial polycondensation, the aqueous phase is charged with bisphenol A sodium salt and the organic phase with a 1:1 mixture of isophthaloyl and terephthaloyl dichlorides in dichloromethane, maintaining a total aroyl dichloride-to-bisphenol A molar ratio of 1.00:1.00. Sodium hydroxide is metered to hold pH at 10.0–11.0, and benzyltriethylammonium chloride is added at 0.5–1.0 mol% as phase transfer catalyst; reaction temperature is held at 5–25°C because the acylation exotherm raises the methylene chloride reflux rate and can dephase the stirrer vortices. After 10–30 min of high-shear agitation at 1000 rpm, the organic layer is separated, washed with dilute hydrochloric acid, and precipitated in methanol; the dried polymer has a glass transition near 190–210°C and a light transmittance above 85% at 3.2 mm when tested to ASTM D1003-13. Flame retardance verification uses UL 94 V-0 at 1.5 mm thickness, and flexural modulus is reported to ISO 178:2019. Terminal product types include high-heat automotive reflector substrates, electrical connector bodies for reflow soldering, and transparent optical films where birefringence below 5 nm is specified by the downstream converter. Published data for this specific configuration is limited in the open literature with respect to trace acyl chloride hydrolysis products; therefore, resin qualification requires in-house gas chromatography for unreacted aroyl chloride below 50 mg/kg before compounding.
Tetrabromobisphenol A is obtained by brominating bisphenol A with molecular bromine at a 4.0:1 bromine-to-bisphenol A molar ratio, corresponding to a theoretical bromine content of 58.8 wt%. The reaction is conducted in methanol or a methanol-water medium at 20–40°C, with bromine fed over 2–6 h; hydrogen peroxide is sometimes used to oxidize the by-product hydrogen bromide back to bromine, reducing net halogen loss. The exotherm is controlled by jacket cooling because the substitution reaction releases sufficient heat to exceed the solvent boiling point if bromine is added above 5 kg/min per m³; therefore, production reactors are fitted with reflux condensers and pH-controlled scrubbing of HBr vapor. The precipitated product is washed with water, neutralized, and dried at 80–100°C to below 0.2% moisture. In FR-4 epoxy laminates, tetrabromobisphenol A is either reacted into the epoxy backbone as a brominated bisphenol A diglycidyl ether or added as a reactive brominated chain extender, with a bromine content between 18 and 21 wt% in the cured prepreg to achieve UL 94 V-0 at 1.6 mm laminate thickness. Compliance review includes RoHS Directive 2011/65/EU for homogeneous material restrictions and REACH Regulation (EC) No 1907/2006 for registered substance exposure scenarios; when halogen-free procurement is imposed, the board specification follows IEC 61249-2-21:2003, which excludes this chemistry. Terminal product types are multilayer printed circuit boards, power supply substrates, and encapsulant formulations for high-voltage connectors where the curing exotherm must remain below 180°C to avoid bromoalkane off-gassing.
Bisphenol A is converted to the difunctional benzoxazine monomer BA-a through reaction with aniline and paraformaldehyde at a molar ratio of 1:2:4. The synthesis uses toluene as azeotropic solvent at 85–110°C to remove water of condensation over 4–8 h; the organic layer is then concentrated under vacuum below 100 mbar and the monomer is isolated as a viscous liquid that solidifies below 50°C. Cure of BA-a proceeds by thermally activated ring-opening polymerization without a catalyst; differential scanning calorimetry to ISO 11357-2:2020 typically records an exotherm onset near 180°C and a peak near 230°C, which defines the lower processing floor for void-free laminates because residual solvent and water must be removed before vitrification. The mixing ratio in solvent prepreg is usually 60–70 wt% monomer in methyl ethyl ketone, with 0.5–2.0 wt% imidazole or phenolic accelerators used only when hot-press cycle time must be reduced below 30 min. Mechanical qualification follows ASTM D638-22 for tensile strength and IPC-4101 for laminate quality; flame retardance is evaluated to UL 94 V-0 at 1.6 mm. Terminal product types include high-temperature composite prepregs for aerospace interiors, bromine-free copper-clad laminates, and under-hood automotive components where the cured network retains flexural modulus above 3.5 GPa at 150°C.
Competitive Bisphenol A prices that fit your budget—flexible terms and customized quotes for every order.
For samples, pricing, or more information, please contact us at +8615365186327 or mail to sales3@ascent-chem.com.
We will respond to you as soon as possible.
Tel: +8615365186327
Email: sales3@ascent-chem.com
Flexible payment, competitive price, premium service - Inquire now!
Bisphenol A (BPA; CAS 80-05-7) is a crystalline aromatic monomer with the formula C15H16O2 and a molecular weight of 228.29 g mol−1. The product is recovered as white prills, flakes, or molten feed; its melting point is 155–157 °C, and its solid density is approximately 1.20 g/cm³ at 25 °C. Industrial synthesis proceeds by acid-catalyzed condensation of phenol and acetone, followed by purification to product grades coded according to downstream use: polycarbonate-grade BPA-PC, epoxy-grade BPA-EP, and optical polycarbonate-grade BPA-O. Commercial specifications differ from bisphenol F and bisphenol S in the dimethylmethylene bridge, which imposes higher steric rigidity in derived polymers and raises the glass transition of polycarbonate and epoxy networks relative to the methylene-bridged bisphenol F analogue.
For interfacial polycarbonate production, BPA is dissolved in aqueous sodium hydroxide to generate the disodium phenoxide, then reacted with phosgene in a dichloromethane phase at pH 10.5–11.0. The reaction is exothermic and is operated under continuous phase separation; molecular weight is controlled with p-tert-butylphenol chain stopper. Residual free phenol in BPA functions as a monofunctional terminator and reduces number-average molecular weight if present above release limits. The ortho–para isomer 2,4′-BPA is particularly detrimental because it disrupts polymer symmetry, reduces optical transmission, and lowers heat deflection temperature in molded articles. Production-scale polymerization units therefore impose incoming BPA purity limits that are tighter than those used in lower-molecular-weight epoxy resin synthesis.
Process limitations are defined by the monomer’s monofunctional impurities and color precursors. Free phenol depresses molecular weight in interfacial polycarbonate because each phenol molecule consumes a reactive chloroformate end group and terminates chain growth. The same impurity is less restrictive in epoxy resin production because phenolic hydroxyl groups participate in etherification with epichlorohydrin. The 2,4′-BPA isomer, in contrast, is carried through polycarbonate polymerization and places one hydroxyl group in a sterically hindered position; the resulting irregular backbone reduces the glass transition temperature and increases haze in transparent applications. Color precursors such as oxidized quinone species and iron residues raise yellowness even when present at low parts-per-million levels.
Representative commercial release limits for the main BPA product models follow.
| Parameter | BPA-PC polycarbonate grade | BPA-EP epoxy grade | BPA-O optical grade |
|---|---|---|---|
| p,p′-BPA purity | ≥99.5% | ≥99.0% | ≥99.9% |
| 2,4′-BPA isomer | ≤0.30% | ≤1.0% | ≤0.10% |
| Free phenol | ≤100 mg/kg | ≤500 mg/kg | ≤50 mg/kg |
| Iron | ≤1.0 mg/kg | ≤2.0 mg/kg | ≤0.5 mg/kg |
| Water | ≤0.10 wt% | ≤0.20 wt% | ≤0.05 wt% |
| APHA color | ≤20 | ≤50 | ≤10 |
Analytical control is commonly performed by HPLC with ultraviolet detection at 278 nm for p,p′-BPA and 2,4′-BPA, gas chromatography with flame ionization detection for free phenol, inductively coupled plasma optical emission spectrometry for iron, and ASTM D1209-05 for platinum-cobalt color on a molten or methanolic sample. The optical-grade column is differentiated by the low iron and phenol ceilings, which reduce absorbance in the visible and near-UV range used for molded lenses and optical storage media. Exact limits vary by producer and polymerization technology.
Industrial BPA units choose between homogeneous acid catalysts and sulfonated polystyrene ion-exchange resins. The anhydrous hydrochloric acid route gives high selectivity but requires corrosion-resistant equipment and thorough chloride removal from recycle streams. The ion-exchange route allows continuous fixed-bed operation and reduces chloride burden, yet water generated by condensation must be stripped from the recycle acetone because water inhibits catalyst activity and depresses equilibrium conversion. A large excess of phenol relative to acetone is maintained to suppress oligomer and chroman by-products; after condensation, the phenol-BPA adduct is crystallized, and residual phenol is recovered by vacuum stripping.
Thermal degradation becomes a process conflict during purification. Melt crystallization and falling-film evaporation are preferred over prolonged high-temperature distillation because BPA develops yellow color bodies when held at elevated temperature. Vacuum operation at pressures below 1.0 kPa lowers distillation temperature and limits degradation; wiped-film evaporators with short residence time are used for final phenol removal. Published data for specific residence-time limits vary by equipment supplier, but melt processing downstream is normally conducted below 180 °C for BPA monomer storage and below 320 °C for its polycarbonate derivative.
Production-scale experience shows that BPA handling bottlenecks arise from dust formation, caking in storage silos, and melt-line freeze-off. Prilled BPA with a controlled particle-size distribution reduces dust, but rotary valves and pneumatic conveying lines require nitrogen inerting to avoid combustible dust hazards. Molten BPA transfer requires jacketed lines maintained at 160–170 °C; overcooling below 155 °C causes solidification in the transfer line, while prolonged heating above 180 °C raises color and phenol regeneration. Field data from continuous polycarbonate reactors indicate that batch-to-batch variation in BPA free phenol is a common source of molecular-weight drift when the unit operates under fixed chain-stopper addition.
For liquid epoxy resin synthesis, BPA is etherified with excess epichlorohydrin under alkaline conditions to form diglycidyl ether of bisphenol A. The resulting standard liquid resin has an epoxy equivalent weight of 182–192 g/eq and a viscosity of 11,000–14,000 mPa·s at 25 °C, measured by ASTM D1652-11 for epoxy equivalent weight and ASTM D2196-20 for rotational viscosity. Higher-molecular-weight solid BPA epoxy resins are produced by advancement with additional BPA; these products range from solid bisphenol A-diglycidyl ether resins with epoxy equivalent weights above 400 g/eq to phenoxy resins used in coatings. The aromatic ring and dimethylmethylene bridge give cured BPA networks higher glass transition temperatures and better barrier properties than bisphenol F analogues, but also higher viscosity and a greater tendency to crystallize at low temperatures.
When formulators substitute bisphenol F diglycidyl ether for BPA-based diglycidyl ether to reduce solvent demand, the methylene bridge lowers resin viscosity and diluent compatibility but sacrifices part of the BPA structural rigidity. Bisphenol F-based epoxy has a viscosity typically between 2,500 and 4,500 mPa·s at 25 °C, compared with 11,000–14,000 mPa·s for standard BPA liquid resin. After curing with the same amine hardener, the bisphenol F network exhibits a lower dynamic storage modulus in the glassy region and a lower glass transition temperature. BPA-based systems remain preferred where high heat deflection temperature, acid resistance, and dimensional stability justify higher processing viscosity. In bisphenol S, the sulfone group raises melting point and alters electron density at the phenolic oxygen; it is not a direct drop-in for BPA in polycarbonate because its polymerization kinetics and solubility differ, and its toxicological profile has drawn comparable regulatory scrutiny.
Compared with bisphenol AF, which contains a hexafluoroisopropylidene bridge, BPA has lower raw-material cost and higher availability but lower thermal oxidative stability in high-temperature thermoset applications. Bisphenol AF resins provide higher glass transition temperature and chemical resistance but are restricted to specialty applications due to fluorine content and higher price. The selection of BPA over bisphenol S in polycarbonate is driven by polymerization kinetics, monomer purity, and established regulatory history; BPA polycarbonate has a refractive index of 1.584–1.586, high clarity, and good impact resistance, while bisphenol S polycarbonate requires more aggressive reaction conditions and yields a different thermal profile. Published data for these specialty comparisons is limited in open literature; industrial substitution is usually validated case-by-case using differential scanning calorimetry and melt rheology.
During injection molding of BPA-derived polycarbonate, the pellets are dried in a desiccant dryer at 120 °C for 4–6 h to reduce moisture below 0.02 wt%. Melt processing is conducted at 280–320 °C on machines with clamp forces typically between 8,000 and 12,000 kN for optical and technical components. The melt volume-flow rate for injection molding grades is measured by ISO 1133-1:2022 at 300 °C under 1.2 kg load, with common values between 6 and 10 cm³/10 min. Tensile properties determined by ASTM D638-14 for unfilled BPA polycarbonate include tensile strength of 60–70 MPa and elongation at break of 60–150%. Notched Izod impact per ASTM D256-10 ranges from 600 to 850 J/m, and heat deflection temperature per ASTM D648-16 at 0.455 MPa is 135–140 °C. In polycarbonate compounding, a twin-screw extruder with an L/D ratio of 36:1 is common for dispersing additives and removing volatile residuals; vacuum venting at 15–30 kPa strips residual moisture and low-molecular-weight volatiles. Hydrolytic degradation is accelerated if melt residence time is excessive or if the dryer dew point rises above −30 °C; avoid contact with alkaline detergents, amine-containing mold-release agents, and strong bases because they attack the carbonate linkage.
BPA has been used as an acidic color developer in thermal paper, where it protonates the leuco dye after contact with a hot print head. Regulation (EU) 2016/2235 restricts BPA in thermal paper to 0.02% by weight from 2 January 2020 within the European Union. Replacement developers include bisphenol S, Pergafast 201, and sulfonylurea derivatives. Bisphenol S has a higher melting point and lower aqueous leachability but is not a direct functional equivalent because its lower acidity and different solubility alter print density and image stability. Compliance with the thermal-paper restriction does not automatically confer compliance with food-contact standards; separate migration testing under FDA 21 C.F.R. 175.300 and 177.1580 applies to BPA-based epoxy coatings and polycarbonate resins used in food-contact articles.
Food-contact approvals for BPA-based polycarbonate resins in the United States are premised on migration testing and end-use restrictions under FDA 21 C.F.R. 177.1580; BPA-based epoxy coatings fall under FDA 21 C.F.R. 175.300. REACH Candidate List inclusion as a substance of very high concern for endocrine-disrupting properties means that EU suppliers must provide safety data sheets and communicate safe-use information under REACH Article 33. Proposition 65 listing in California imposes warning requirements for certain consumer products. These regulatory obligations differ from product specification conformity and are managed separately from purity and isomer limits in commercial contracts.
In polysulfone synthesis, BPA is converted to the corresponding dipotassium phenoxide and subjected to nucleophilic aromatic substitution with 4,4′-dichlorodiphenyl sulfone in polar aprotic solvents such as dimethyl sulfoxide or sulfolane. The resulting polymer contains the dimethylmethylene bridge and sulfone linkage; its glass transition temperature is approximately 185 °C as measured by ISO 11357-2:2020. Continuous degassing of water and careful stoichiometric control are required because phenoxide hydrolysis regenerates free BPA and shifts molecular weight. Compared with BPA-based polycarbonate, polysulfone tolerates higher service temperature and better hydrolytic stability, but the monomer purity requirements remain similar: residual phenol and monofunctional phenolic species reduce molecular weight, and polar impurities alter the electrophilic substitution kinetics in the polymerization reactor.
