由双酚A结晶母液的裂解产物合成双酚A反应过程研究

对反应过程所需催化剂种类及其各影响因素进行了考察。研究表明，大孔强酸性离子交换树脂可替代无机酸作为催化剂用于该反应，其中以未经硫基化处理者为佳；原料中水分的存在不利于产物收率和质量，应控制水的质量分数在1％以下。本研究确定的较佳工艺条件为反应温度65℃，停留时间15min、苯酚／对－异丙烯基苯酚摩尔比20，对应的反应收率为98．5％。对双酚A副产物的处理提供了有效方法。     

电子束固化双酚A环氧丙烯酸酯／聚丙烯酸酯体系的研究

本文以接枝型聚丙烯酸酯为主体同时加入双酚Ａ环氧丙烯酸酯,经过电子辐照同化后,形成的聚合物具有一定的剥离强度,持粘性和初粘性。     

低密度聚乙烯接枝烯基双酚A醚对HDPE／PC共混体系性能的影响

本文采用烯基双酚Ａ醚接枝低密度聚乙烯（ＬＤＰＥ－ｇ－ＤＢＡＥ）作为高密度聚乙烯／聚碳酸酯（ＨＤＰＥ／ＰＣ）共混体系的增容剂,初步研究了ＬＤＰＥ－ｇ－ＤＢＡＥ对ＨＤＰＥ／ＰＣ体系性能的影响。通过对共混物形态观察、耐热性能及力学性能测试,发现ＬＤＰＥ－ｇ－ＤＢＡＥ对ＨＤＰＥ／ＰＣ体系有良好的增容效果;并发现了增容剂的最佳用量质量比大致为１０％,提高增容剂的接枝率更有利于改善共混物的性能。６５／３５ＨＤＰＥ／ＰＣ共混物的ＨＤＴ为９２℃,拉伸强度３０２ＭＰａ,冲击强度２９８ｋＪ／ｍ２,分别比未加增容剂时的８２℃,２７３ＭＰａ和１５５ｋＪ／ｍ２有较大提高。     

Removal of bisphenol A by a nanofiltration membrane in view of drinking water production

The efficiency with which a nanofiltration membrane (Desal 5 DK) removes bisphenol A (BPA) was investigated, together with the mechanisms involved. Whereas high retention (>90%) was obtained at the beginning of the filtration, the observed retention coefficient (R_obs) decreased to around 50% when the membrane became saturated, due to adsorption of BPA onto the membrane structure. The presence of ions (Na⁺, Cl⁻) affects the R_obs, this effect being attributed to a change in BPA hydrodynamic radius. Moreover, in our operating conditions, the presence of natural organic matter (1 mg/L) in the feed solution does not lead to variation in BPA retention at steady state.     

Removal of bisphenol A and 17α-ethinyl estradiol from landfill leachate using single-walled carbon nanotubes

In this study, the adsorption of bisphenol A (BPA) and 17α-ethinyl estradiol (EE2) from landfill leachate onto single-walled carbon nanotubes (SWCNTs) was investigated. Different leachate solutions were prepared by altering the pH, ionic strength, and dissolved organic carbon (DOC) in the solutions to mimic the varying water conditions that occur in leachate during the various stages of waste decomposition. The youngest and oldest leachate solutions contained varying DOC and background chemistry and were represented by leachate Type A (pH = 5.0; DOC = 2500 mg/L; conductivity = 12,500 μS/cm; [Ca²⁺] = 1200 mg/L; [Mg²⁺] = 470 mg/L) and Type E (pH = 7.5; DOC = 250 mg/L; conductivity = 3250 μS/cm; [Ca²⁺] = 60 mg/L; [Mg²⁺] = 180 mg/L). These solutions were subsequently combined in different ratios to produce intermediate solutions, labeled B-D, to replicate time-dependent changes in leachate composition. Overall, a larger fraction of EE2 was removed as compared to BPA, consistent with its higher log K_OW value. The total removal of BPA and EE2 decreased in older leachate solutions, with the adsorptive capacity of SWCNTs decreasing in the order of leachate Type A > Type B > Type C > Type D > Type E. An increase in the pH from 3.5 to 11 decreased the adsorption of BPA by 22% in young leachate and by 10% in old leachate. The changes in pH did not affect the adsorption of EE2 in the young leachate, but did reduce adsorption by 32% in the old leachate. Adjusting the ionic strength using Na⁺ did not significantly impact adsorption, while increasing the concentration of Ca²⁺ resulted in a 12% increase in the adsorption of BPA and a 19% increase in the adsorption of EE2. DOC was revealed to be the most influential parameter in this study. In the presence of hydrophilic DOC, represented by glucose in this study, adsorption of the endocrine disrupting compounds (EDCs) onto the SWCNTs was not affected. In the absence of SWCNTs, hydrophobic DOC (i.e., humic acid) adsorbed 15-20% of BPA and EE2. However, when the humic acid and SWCNTs were both present, the overall adsorptive capacity of the SWCNTs was reduced. Hydrophobic (π-π electron donor-acceptor) interactions between the EDCs and the constituents in the leachate, as well as interactions between the SWCNTs and the EDCs, are proposed as potential adsorption mechanisms for BPA and EE2 onto SWCNTs.     

双酚A型二胺和二酐合成可溶性聚酰亚胺的研究

采用2,2-双[4-(4-氨基苯氧基)苯基]丙烷(BAPP)和2,2-双[4-(3,4-二羧基苯氧基)苯基]丙烷二酐(BPADA)为单体,N,N-二甲基甲酰胺(DMF)为溶剂,通过常规的两步法,并分别经热亚胺化和化学亚胺化过程合成了双酚A型聚酰亚胺(PI).用FTIR、DSC、TGA等对聚合物的结构和性能进行了表征.F...     

Determination of bisphenol A in, and its migration from, PVC stretch film used for food packaging

Bisphenol A (BPA) is used as an additive in polyvinyl chloride (PVC) products, including stretch films used for food packaging. The BPA contents were investigated of several brands of stretch film bought locally but marketed internationally or throughout Spain and which were presumably produced at different manufacturing plants. Their major components were identified by FTIR (Fourier Transform Infrared Spectrometry) and horizontal attenuated total reflectance, and the migration of BPA from these materials into the standard European Union food simulants was determined by high-performance liquid chromatography (HPLC) using both fluorescence (FL) and ultraviolet (UV) detection, the identity of the analyte being confirmed by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS). The two HPLC detection methods had different detection limits (30 μg l^-1 for UV, 3 μg l^-1 for FL), but afforded virtually identical BPA determinations for the samples tested. BPA contents ranging from 40 to 100 mg kg^-1 were found in three of the five PVC-based films analysed, and a content of 500 mg kg^-1 was found in a fourth; for these determinations, extraction into acetonitrile was used. In standard tests of migration into water, 3% acetic acid and olive oil over 10 days at 40°C, migration from a given film was in all cases greatest into olive oil. Migration from the films with non-zero BPA contents ranged from 3 to 31 μg dm^-2, values higher than those reported for many other food-contact materials, but lower than the European Union specific migration limit for BPA. PVC stretch film nevertheless may make a significant contribution to contamination of foodstuffs by BPA, and should be taken into account in estimating BPA intake or exposure to this substance.     

Adsorption of Bisphenol A to a Carbon Nanotube Reduced Its Endocrine Disrupting Effect in Mice Male Offspring

Soluble carbon nanotubes (CNTs) have shown promise as materials for adsorption of environmental contaminants such as Bisphenol A (BPA), due to the high adsorption capacity and strong desorption hysteresis of BPA on CNTs. The adsorption of BPA to CNTs may change the properties of both BPA and CNTs, and induce different toxicity to human and living systems from that of BPA and CNTs alone. Herein, we report that oral exposure of BPA/MWCNT–COOH (carboxylated multi-walled carbon nantubes) adduct to mice during gestation and lactation period decreased the male offspring reproductive toxicity compared with those induced by BPA alone. The adduct decreased malondialdehyde (MDA) level in testis and follicle-stimulating hormone (FSH) in serum, but increased the level of serum testosterone in male offspring in comparison to BPA alone. Our investigations broadened the knowledge of nanotoxicity and provided important information on the safe application of CNTs.     

Multifunctional biomagnetic capsules for easy removal of phenol and bisphenol A

This paper reports fabrication, optimization and characterization of multifunctional biocapsules with immobilized enzyme using a layer-by-layer configuration and their application for removal of phenol and bisphenol A (BPA). The method is based on the combined use of enzymatic oxidation of the BPA and subsequent binding of the reaction product onto a chitosan core biopolymer. This platform has multiple functions including: (1) enzymatic degradation of BPA, (2) adsorption of the degraded compound within the core material, (3) colorimetric quantification and (4) magnetic capabilities. We examined various configurations of core/shell structures of alginate and chitosan and determined the stability and the optimum conditions in which these structures provide the most effective removal capacity. The amount of BPA that can be removed per capsule is 5.6 ppm while phenol can be removed up to 10 ppm per capsule within 15 h.     

Photo-Fenton-like treatment of BPA: Effect of UV light source and water matrix on toxicity and transformation products

UV-A (near-UV), UV-C (short-UV) and visible-light assisted Fenton-like treatment of Bisphenol A (BPA) was investigated in pure water and raw freshwater samples spiked with BPA. Treatment performances were evaluated in terms of BPA degradation, dissolved organic carbon (DOC) removal and H₂O₂ consumption rates. Complete BPA degradation accompanied with significant DOC removal was achieved for all studied processes. Increasing the initial solution pH only exhibited a negative effect on treatment efficiencies when bicarbonate alkalinity was used for pH adjustment, whereas the raw freshwater matrix and irradiation type also influenced oxidation rates appreciably. Acute toxicity analysis employing Vibrio fischeri revealed that the inhibitory effect of BPA decreased significantly during the course of Photo-Fenton-like treatment. Several transformation products could be identified via HPLC and GC–MS analyses including hydroxylated phenolic compounds (hydroquinone; 2-methoxy, 1-4-benzenediol; 4-isopropenylphenol; 4′-hydroxy-acetophenone; 1-(4-cyclohexylphenyl) ethanone; 4-isopropylenecatechol; 4-4′-dihydroxybenzophenone; 4-ethyl,1,3-benzenediol), as well as the ring opening products hexanoic acid methyl ester, fumaric, succinic and oxalic acids. A reaction pathway featuring hydroxylation, dimerization and ring opening steps is proposed.