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It is known that the industry already abandoned the use of bisphenol A (BPA)-based epoxy resins as internal coatings for some canned food products (e.g. infant formula, soups). The presence of bisphenol A (BPA) in foods has also been extensively investigated, especially since late 2000. However, information on temporal trends of BPA occurrence in foods is very limited. It is not clear if BPA-based epoxy resins are still being used in internal coating for many other canned foods and if the overall exposure to BPA through consumption of canned foods has significantly decreased. As part of the Canadian total diet study (TDS) program, we have been analysing food samples for BPA since 2008. In this study, results of BPA in samples of different composite canned foods from 2008-2020 TDS were reported. Clear temporal trends were observed for canned fish and soups, with BPA levels being significantly reduced since 2014 for canned fish products and 2017 for canned soups. Temporal trends were not observed for canned evaporated milk, luncheon meats, and vegetables, with even the highest levels of BPA being detected in recent samples for evaporated milk (57 ng/g), luncheon meats (56 ng/g), and baked beans (103 ng/g). This seems to indicate that BPA-based epoxy resins are still being used in the internal coatings for these canned foods products. Thus, analysis of canned food samples for BPA should be continued for exposure assessment.

A renewable bisepoxide, SYR-EPO, was prepared from syringaresinol, a naturally occurring bisphenol deriving from sinapic acid, by using a chemo-enzymatic synthetic pathway. Estrogenic activity tests revealed no endocrine disruption for syringaresinol. Its glycidylation afforded SYR-EPO with excellent yield and purity. This biobased, safe epoxy precursor was then cured with conventional and renewable diamines for the preparation of epoxy-amine resins. The resulting thermosets were thermally and mechanically characterized. Thermal analyses of these new resins showed excellent thermal stabilities (T d5 % =279-309 °C) and T g ranging from 73 to 126 °C, almost reaching the properties of those obtained with the diglycidylether of bisphenol A (DGEBA), extensively used in the polymer industry (T d5 % =319 °C and T g =150 °C for DGEBA/isophorone diamine resins). Degradation studies in NaOH and HCl aqueous solutions also highlighted the robustness of the syringaresinol-based resins, similar to bisphenol A (BPA). All these results undoubtedly confirmed the potential of syringaresinol as a greener and safer substitute for BPA., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Rehabilitation of aged drinking water pipes is an extensive renovation and increasingly topical in many European cities. Spray-on-lining of drinking water pipes is an alternative cost-effective rehabilitation technology in which the insides of pipes are relined with organic polymer. A commonly used polymer is epoxy resin consisting of monomer bisphenol A (BPA). Leaching of BPA from epoxy lining to drinking water has been a concern among public and authorities. Currently epoxy lining is not recommended in some countries. BPA leaching has been demonstrated in laboratory studies but the behavior and ageing process of epoxy lining in situ is not well known. In this study 6 locations with different age epoxy linings of drinking water pipes done using two distinct technologies were studied. While bisphenol F, 4-n-nonylphenol, and 4-t-octylphenol were rarely found and in trace concentrations, BPA was detected in majority of samples. Pipes lined with the older technology (LSE) leached more BPA than those with more recent technology (DonPro): maxima in cold water were 0.25 μg/L and 10 ng/L, respectively. Incubation of water in pipes 8-10 h prior to sampling increased BPA concentration in cold water 1.1-43-fold. Hot water temperature caused even more BPA leaching - at maximum 23.5 μg/L. The influence of ageing of epoxy lining on BPA leaching on could be shown in case of LSE technology: locations with 8-9 years old lining leached 4-20-fold more BPA compared to a location with 2-year-old lining. Analysis of metals showed that epoxy lining can reduce especially iron concentration in water. No significant burden to water could be shown by the analyzed 72 volatile organic compounds, including epichlorhydrin, precursor used in epoxy resin. Estrogenicity was detected in water samples with the highest BPA loads. Comparable responses of two yeast bioreporters (estrogen receptor α and BPA-targeted) indicated that bisphenol-like compounds were the main cause of estrogenicity. Compared to the estimated average daily BPA exposure, additional BPA load via cold drinking water in the studied locations was low, maximum 8.7%. However, hot water should also be considered as exposure source due to higher BPA concentrations. Epoxy lined locations should be monitored in future in order to evaluate ageing process and control increasing leaching of potentially harmful chemicals., (Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Novel hydrogel beads having molecular adsorption abilities were prepared from carboxymethylcellulose sodium salt (CMC) and β-cyclodextrin (β-CD) by suspension crosslinking, using ethylene glycol diglycidyl ether (EGDE) in basic medium as a crosslinking agent. FTIR and solid-state NMR spectroscopic analysis revealed that the amount of incorporated β-CD and crosslinking densities within the hydrogel bead structures are strongly dependent on the molar feed ratio of β-CD to CMC during preparation. The hydrogel beads showed water-swelling capacities of 70-200 mL/g-polymer, with decreases in capacity associated with increased amounts of β-CD incorporated in the gel structure. The hydrogel beads also showed a high adsorption capacity toward bisphenol A (BPA) in water. Batch BPA-adsorption experiments were analyzed employing Langmuir isotherm models; hydrogel bead adsorption isotherms for BPA could be fitted to the Langmuir model. The maximum BPA-adsorption among the prepared series of hydrogel beads amounted to 167 μmol g(-1)., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Diglycidyl ether of bisphenol A (DGEBA), a key intermediate for epoxy resins, provides strong adhesion, processability and the resulting thermoset boasts high cross linking density. However, the inherent brittleness and susceptibility to cracking restrict its advanced applications. To overcome these drawbacks, CO2 fixed cyclic carbonate from castor oil (CCO) was synthesized from epoxidised castor oil (ECO) and used in varying quantities as a toughening agent for amine cured DGEBA. Different amines have been utilized to cure the epoxy and to study the structure–property relationship by fixing the amount of CCO. The inclusion of 10% CCO resulted in improvement in the tensile strength, storage modulus, flexural modulus, and impact strength of the epoxy‐urethane hybrid. Moreover, the epoxy‐urethane networks had reduced cross linking density imparted by the fatty acid units of CCO and the presence of unreacted carbonate groups facilitated molecular movement, thereby contributing to energy dissipation during the deformation process. Further incorporation of the CCO lowers the mechanical properties of the hybrids due to a reduction in cross linking density. Trimethylolpropane tris[poly(propyleneglycol)amine terminated] ether cured system exhibited the highest thermal stability compared to hexamethylene diamine, isophorone diamine, and 4,7,10‐trioxa‐1,13 tridecanediamine. The Tg decreased as the CCO content increased, while the water contact angle increased. [ABSTRACT FROM AUTHOR]

The massive consumption of fossil fuels has led to the serious accumulation of carbon dioxide gas in the atmosphere and global warming. Bioconversion technologies that utilize biomass resources to produce chemical products are becoming widely accepted and highly recognized. The world is heavily dependent on petroleum-based products, which may raise serious concerns about future environmental security. Most commercially available epoxy resins (EPs) are synthesized by the condensation of bisphenol A (BPA), which not only affects the human endocrine system and metabolism, but is also costly to produce and environmentally polluting. In some cases, straw tar-based epoxy resins have been recognized as potential alternatives to bisphenol A-based epoxy resins, and are receiving increasing attention due to their important role in overcoming the above problems. Using straw tar and lignin as the main raw materials, phenol derivatives were extracted from the middle tar instead of bisphenol A. Bio-based epoxy resins were prepared by replacing epichlorohydrin with epoxylated lignin to press carbon fiber sheets, which is a kind of bio-based fine chemical product. This paper reviews the research progress of bio-based materials such as lignin modification, straw pyrolysis, lignin epoxidation, phenol derivative extraction, and synthesis of epoxy resin. It improves the performance of carbon fiber-reinforced plastic (CFRP) while taking into account the ecological and environmental protection, so that the epoxy resin is developed in the direction of non-toxic, harmless and high-performance characteristics, and it also provides a new idea for the development of bio-based carbon fibers. [ABSTRACT FROM AUTHOR]

Bisphenol A (BPA) has been extensively applied for the production of polycarbonate plastics and epoxy resins, which has gained increasing attention due to its ubiquitous presence and adverse effect on ecosystems and human health. Various biological strategies (such as BPA biodegradation by bacteria, fungi, algae, and plants) have been developed to address BPA contamination issue. This review systematically summarized and analyzed recent advances in biological methods for BPA degradation, including bacterial, fungal, algal, and plants, highlighting the efficiency and mechanisms of BPA degradation. By analyzing the common intermediates of BPA biodegradation by bacteria, fungi, algae and plants reported in previous studies, the typical biodegradation pathways were proposed. The review further addressed the contentious topic of anaerobic BPA degradation, noting the scarcity of definitive evidence endorsing this process. Further, the common enzymes and typical enzymatic reactions involved in the biodegradation process of BPA were summarized. This review will deepen the understanding of BPA biodegradation, leading to the discovery of more efficient microorganisms and highly effective enzymatic catalysts for remediating BPA contamination. [ABSTRACT FROM AUTHOR]

Glycidyl ethers are prepared from a series of furan‐based diols and cured with a diamine to form thermosets. The furan diols demonstrate lower toxicity than bisphenol‐A in a prior study. The diglycidyl ethers show improved thermal stability compared to the parent diols. Cured thermosets are prepared at elevated temperature using isophorone diamine (IPDA). Glass transition temperatures are in the range of 30–54 °C and depend on the structure of the furan diol. Coatings are prepared on steel substrates and show very high hardness, good adhesion, and a range of flexibility. Properties compare favorably with a control based on a bisphenol‐A epoxy resin. The study demonstrates that epoxy resins based on furan diols, which have been shown to have lower toxicity than bisphenol‐A, can form thermosets having properties comparable to a standard epoxy resin system; and thus, are viable as replacements for bisphenol‐A epoxy resins. [ABSTRACT FROM AUTHOR]

Conventionally bisphenol A epichlorohydrin (BPA-EC) is used as epoxy resin and cycloaliphatic amine is used as a curing agent for industrial corrosion mitigation. However, due to their noticeable toxicity, alternative curing agents and decreasing the conventional compounds in the coating is a demanding task. Aminopropyltriethoxysilane can be an alternative curing agent and lignin can partially replace BPA-EC , as the preliminary adhesion study of the developed coating suggested. However, other characteristics of the coating need to be examined to evaluate the coating holistically. Hydrophobicity is such a characteristic, which plays a leading role in enhancing the anti-corrosivity of the coating, especially for coating, implemented on submerged metallic bodies. The current study attempted to find the justification of BPA-EC in terms of hydrophobicity. The response surface methodology has been followed using the Box–Behnken design model to investigate the respective and cumulative effect of each element. Initially, the model has a P value of 0.0198, with some of the terms not significant. Thus, a modified model has been introduced keeping only the terms, close to the significant p-value of 0.05. Finally, a P-value of 0.0001 has been achieved. Experimental verification of the response values exhibited an average error of 9.84%. The result showed a non-linear association between the respective constituents. Statistics showed that BPA-EC positively impacts hydrophobicity. Thus, to maintain the hydrophobicity rather than 100% replacement by lignin, a minimum level of bisphenol epichlorohydrin is obligatory; ensuring the legitimacy of the constituents in the coating. [ABSTRACT FROM AUTHOR]

To protect carbon steel from degradation via corrosion, it is usually coated using a multilayer system of paints composed of petroleum-based polymers. The chemical industry is currently moving towards more sustainable chemistry, in which one of the main objectives is to reduce fossil fuel use and the derived raw materials. However, the replacement of petroleum-based raw materials with those that are bio-based is not straightforward since the properties of these new materials are often inferior to the traditional ones. One of the most used resins in primer paints is Diglycidyl ether bisphenol A (DGEBA). This is an epoxy resin synthesized from bisphenol A (BPA), a toxic and carcinogenic petroleum-based compound. This study investigates the substitution of the primer coating in a three-layer coating system with two different types of primer coating formulations, one which is partially bio-based and another that is BPA-free. The corrosion protection effectiveness of these sustainable coatings is assessed not only at the laboratory scale but also in real offshore conditions. Moreover, the adhesion of the different coating systems is evaluated before and after each ageing test. The results reveal that these novel coatings exhibit comparable performance to conventional paints while providing a more sustainable corrosion protection alternative. [ABSTRACT FROM AUTHOR]

Bisphenol A (BPA) is an endocrine-disruptive chemical that is widely utilized in the production of polycarbonate plastic and epoxy resin, which are used to make a wide range of consumer products, food and drink containers, and medical equipment. When the potential risk of BPA emerged, it was substituted by allegedly less harmful substitutes such as bisphenols S, F, B, and AF. However, evidence suggests that all bisphenols can have endocrine-disruptive effects, while the extent of these effects is unknown. This study aimed to determine effect of BPA, BPAF, BPB, BPF, and BPS on viability and steroidogenesis in human adrenocortical carcinoma cell line in vitro. The cytotoxicity of bisphenols was shown to be considerable at higher doses. However, at low concentrations, it improved viability as well as steroid hormone secretion, indicating that bisphenols have a biphasic, hormetic effect in biological systems. The results are consistent with the hypothesis that bisphenols selectively inhibit some steroidogenic enzymes. These findings suggest that bisphenols have the potential to disrupt cellular steroidogenesis in humans, but substantially more detailed and systematic research is needed to gain a better understanding of the risks associated with bisphenols and their endocrine-disrupting effect on humans and wildlife. [ABSTRACT FROM AUTHOR]

Diphenolic acid, or 4,4-bis(4-hydroxyphenyl)pentanoic acid, represents one of the potentially most interesting bio-products obtainable from the levulinic acid supply-chain. It represents a valuable candidate for the replacement of bisphenol A, which is strongly questioned for its toxicological issues. Diphenolic acid synthesis involves the condensation reaction between phenol and levulinic acid and requires the presence of a Brønsted acid as a catalyst. In this review, the state of the art related to the catalytic issues of its synthesis have been critically discussed, with particular attention to the heterogeneous systems, the reference benchmark being represented by the homogeneous acids. The main opportunities in the field of heterogeneous catalysis are deeply discussed, as well as the bottlenecks to be overcome to facilitate diphenolic acid production on an industrial scale. The regioselectivity of the reaction is a critical point because only the p,p′-isomer is of industrial interest; thus, several strategies aiming at the improvement of the selectivity towards this isomer are considered. The future potential of adopting alkyl levulinates, instead of levulinic acid, as starting materials for the synthesis of new classes of biopolymers, such as new epoxy and phenolic resins and polycarbonates, is also briefly considered. [ABSTRACT FROM AUTHOR]

Bisphenol A (BPA), a compound widely used in industrial applications, has raised concerns due to its environmental impact. As a key component in the manufacture of polycarbonate plastics and epoxy resins used in many consumer products, concerns about potential harm to human health and the environment are unavoidable. This study seeks to address these concerns by evaluating a range of potential BPA alternatives, focusing on their ecotoxicological properties. The research examines 76 bisphenols, including BPA derivatives, using a variety of in silico ecotoxicological models, although it should be noted that these models were not developed exclusively for this particular class of compounds. Consequently, interpretations should be made with caution. The results of this study highlight specific compounds of potential environmental concern and underscore the need to develop more specific models for BPA alternatives that will allow for more accurate and reliable assessment. [ABSTRACT FROM AUTHOR]

Bisphenol A, a well-known hormone-disrupting toxin, is employed in producing polycarbonate polymers. Items containing bisphenol A include shockproof panes, lenses, epoxy resins, and bottles found in the covering of specific metallic foodstuff containers, bottle caps, and water system pipes. Human exposure comes predominantly from food contamination, including polycarbonate decanters and food and beverage cans layered using epoxy resins. BPA ingestion can affect children's brains and prostate glands, induce immune response poisoning, alter children's behavior, raise blood pressure, and increase the chance of developing diabetes and heart disease. The goal of this study is to critically evaluate various analytical techniques for detecting BPA in food matrices, as well as the chemical processes and harmful consequences of BPA. [ABSTRACT FROM AUTHOR]

The effects of gamma radiation on the AC electrical properties of highly cross-linked epoxy resin/bisphenol A-based polycarbonate samples have been investigated as a function of concentrations of bisphenol A-based polycarbonate, frequency, and temperature. The composite samples contained different bisphenol A-based polycarbonate concentrations of 0, 4, 8, 10, and 15 by wt%. The gamma irradiation process was performed at different gamma doses of 0, 100, 300, and 500 Gy. The AC electrical properties of the tested samples were studied before and after gamma irradiation within a frequency range of 200 kHz to 1 MHz. The results show that after irradiation, a consistent decrease in complex impedance values ( Z ∗ ) was observed, indicating an increase in conductivity due to radiation-induced scission of the composite structure. Dielectric properties, including the dielectric constant ( ε r ) and dielectric loss ( ε i ), exhibited an increase with higher doses and higher polycarbonate concentrations, signifying the formation of defect sites and charge carrier trapping. AC electrical conductivity ( σ a c ) displayed a notable rise post irradiation, with temperatures ranging from 30 °C to 110 °C, and higher radiation doses and higher temperatures led to increased conductivity. The activation energy (   E a ) decreased as the radiation dose increased, reflecting structural modifications induced by radiation. [ABSTRACT FROM AUTHOR]

The aim of this research was a comparative analysis of selected mechanical properties of epoxy compounds that were modified with metallic fillers and aged in aqueous environments. The tested epoxy compounds consisted of three components: styrene modified epoxy resin based on Bisphenol A, triethylenetetramine curing agent (resin/curing agent ratio of 100:10) and two types of metallic fillers in the form of particles: aluminum alloy (EN AW-2024–AlCu4Mg1) and tin-phosphor bronze (CuSn10P). Samples were subjected to ageing in 4 water environments: low-, medium- and high-mineralized natural water and in a sugar-containing solution for 1, 2 and 3 months. The epoxy samples were subjected to compressive strength tests in accordance with the ISO 604:2002 standard. It was observed that, among others, the compositions seasoned in low-mineralized water usually achieved the highest average compressive strength. As for filler type, using the bronze filler (CuSn10P) usually achieved the highest average compressive strength results. [ABSTRACT FROM AUTHOR]

Low toughness and nonrecyclability severely limit the applications of traditional thermosets and are not in line with the concept of sustainable development. To solve these problems, water is used as the solvent, and a tung oil‐based tetrafunctional carboxylic acid (TFA) curing agent is obtained through a "one‐pot" method based on previous works. This green synthesis method is suitable for synthesizing tung oil‐based polycarboxylic acid curing agents from various olefin‐containing polyacids. At the same time, the vitrimers (DGEBA‐TFA) are prepared with diglycidyl ether of bisphenol (DGEBA) as the skeleton, and applied to carbon fiber reinforced composites (CFRCs). The tensile strength, tensile modulus and elongation at break of DGEBA‐TFA are 64.62 MPa, 2.55 GPa, and 4.31%, respectively, which are comparable to previous works. Hence, the performance of the vitrimers is not reduced while simplifying the experimental steps. Meanwhile, DGEBA‐TFA exhibits excellent self‐healing, shape memory, and recycling abilities. The vitrimers can be reprocessed without additional catalysts, and the recovery rate remained at 91.3% in the third cycle. DGEBA‐TFA‐CFs exhibite excellent tensile strength. This work solves the problems in previous works and makes TFA more likely to be applied into practical industrial production. [ABSTRACT FROM AUTHOR]

Increasing social awareness concerning the design of excellent performance toughening agents to curb the adverse effects of insufficient toughness on the wide range of applications of epoxy resin (EP). Herein, a small amount of sorbitol was doped into carbocyclic inositol as a core monomer, and bisphenol-A and epichlorohydrin were used to produce epoxide-terminated hyperbranched polyether by one-pot preparation method. After that, the prepared polymer was used as modifier to improve the toughness and strength of petroleum-based EPs. Results demonstrated that after adding the homemade epoxy-terminated hyperbranched polyether (EHBPE) to the EP, the polyether prepared with the ratio of sorbitol and inositol displayed significant advantages compared with the polyether with monomers using only sorbitol and inositol, respectively. In particular, the impact, and tensile strengths of EHBPE-IS/EP cured sample with EHBPE-IS loading at 20% were increased by 197.5%, 139.6%, respectively, compared with those of neat EP. In brief, EHBPE-IS, a member of the family of EHBPEs, provided a facile method for the preparation of bifunctional modifier for tough and strong EP with promising industrial applications. [ABSTRACT FROM AUTHOR]

Increasing levels of bisphenol A (BPA), classified as an endocrine-disrupting compound, in the environment have raised concerns because of its detrimental impact on human and animal health. BPA has been detected in soil and water and even as a volatile compound in the air primarily because of improper disposal and its extensive use in the production of polycarbonate plastics and epoxy resins. This review comprehensively surveyed recent research focusing on the removal of BPA from water through physicochemical and biological treatments, covering articles published from 2002 to 2023. A range of conventional and non-conventional methods employed for BPA removal is examined, and their limitations in completely degrading BPA in water are acknowledged. Hybrid or integrated treatment systems have been explored, capitalising on the distinctive removal potential of various treatment processes. The literature spanning from 2002 to 2023 underscores the efficacy of hybrid or integrated treatment systems in yielding promising results for BPA removal from water. Furthermore, future directions for BPA removal are outlined, and advancements in treatment technologies developed over the past decade are incorporated. [ABSTRACT FROM AUTHOR]

Crystallization of bisphenol A (DGEBA)- and bisphenol F (DGEBF)-based epoxy resins is a natural property of these oligomers. However, manufacturers of coatings and other systems based on these epoxy resins are making efforts to slow down the crystallization process as much as possible, thereby extending the shelf life and improving the competitiveness of their products. This paper focuses on the kinetics of the crystallization process of epoxy resins and the effect of the presence of a certain degree of crystallinity on selected parameters of epoxy-based materials. Furthermore, an analysis of the impact of a certain degree of crystallinity of the epoxy base on the resulting coating parameters was carried out. The highest value of crystallinity (17%) was achieved in the sample containing the highest proportion of DGEBF in the crystallization phase "c", and the enthalpy of melting (Ht) of the crystalline DGEBF sample was 6.3 J/g. Mechanical parameters as well as chemical and thermal resistance of hydrophobic epoxy systems were investigated. The best abrasion resistance (1.5 cm3/50 cm2) was achieved with the blend containing only amorphous DGEBA. The adhesion of the epoxy samples on concrete was greater than 6.5 MPa. The chemical resistance tests performed showed that, in general, the chemical resistance of epoxy systems decreases with increasing crystallinity content. The tighter arrangement of molecules in the crystalline regions of the epoxy matrix results in an increase in density, strength and hardness. This study presents a comprehensive examination of the crystallization of DGEBA and DGEBF, which is, as yet virtually unavailable. It also contributes to knowledge by outlining the possibility of speeding up or slowing down the crystallization process of epoxy resins, including the principle of selecting nucleating agents. [ABSTRACT FROM AUTHOR]

Bisphenol a (BPA) is an industrial chemical that use in the production of polycarbonate plastics and epoxy resins. Recently, BPA has been received increased attention because of its high production volume, widespread applications and possible health effects. General population are mainly exposed orally to BPA through consumption of food and water stored in containers with BPA. In contrast, in occupational settings workers are exposed to BPA through inhalation of BPA dust particles. This review discusses the controversial of the current findings according to in vitro, in vivo and epidemiological studies. BPA exposure is associated with multi-organ toxicity including reproductive, developmental, metabolic and cardiovascular disorders. In order to protect the environmental and human health, numerous scientific bodies and regulatory agencies developed to keep the BPA exposure within the safe level. The various adverse health effect of BPA lead to development of alternatives with less harmful effect. However, the safety of the alternatives is not fully verified. To conclude, the current restrictions and limitations on use of BPA has reduced potential exposure and consequently possible health effect. However, still there are several unanswered questions regarding to the exact toxic effects, metabolism and fate of BPA on human and environmental health. [ABSTRACT FROM AUTHOR]

The aim of the paper is to assess the impact of the effectiveness of bonding steel elements with paint coating. The adhesive joints were made using two types of the adhesives: two-component epoxy resin adhesive based on Bisphenol A and polyurethane. Three types of adhesive joints were made: (i) reference samples, (ii) samples with a paint polyester coating, and (iii) samples with a zinc primer and paint polyester coating. These coatings were applied using the electrokinetic method. A shear strength test of the adhesive joints (EN DIN 1465 standard), a coating adhesion test (ASTM D3359-B standard), and surface wettability tests (based on contact angle) were used. Through analyzing the test results, it can be seen that the strength of the adhesive joints of the reference samples made with epoxy adhesive is 46% lower than that of the specimens with primer and paint coating applied. However, in the case of the adhesive joints made with the polyurethane adhesive, the aforementioned difference in the strength value of the adhesive joints of the reference samples and paint-coated samples with an applied primer is 76%. Adherends with a paint coating and a previously applied primer obtained the lowest value of the contact angle (38.72°) and are characterized by good wettability. [ABSTRACT FROM AUTHOR]

Bisphenol‐A (BPA)‐based epoxy thermoset has been used commercially due to its many impressive properties. However, it has toxic effects on human health, and it is obtained from petrochemicals so environmentally friendly bio‐based alternatives to substitute BPA for the synthesis of epoxy resins are essential. In this context, a gallic acid amide was synthesized from renewable gallic acid, and diethanol amine. The epoxy resin of the synthesized amide was obtained by the condensation reaction with epichlorohydrin in an alkaline medium. The synthesized epoxy resin was cured with a combination of two hardeners, aliphatic bio‐based poly(amido amine) and aromatic 2‐aminophenyldisulfide at varying weight percentages. The chemical structure of the synthesized epoxy resin was characterized by FTIR and NMR spectroscopic analyses. The synthesized epoxy thermosets showed a maximum tensile strength of 20.04 MPa along with elongation at break of 62.63%, high impact resistance (>19.3 kJ/m2), high scratch hardness (up to 8.5 kg), and high adhesive strength for metal–metal substrates. Moreover, the thermo‐gravimetric analysis showed good thermostability with an initial degradation temperature of 224°C, while the microbial broth culture test confirmed the biodegradability of the thermosets. Thus, this bio‐based epoxy thermoset could find different potential applications including as a binder for eco‐friendly coatings and paints. [ABSTRACT FROM AUTHOR]

In the present study, an epoxy compound, 1,2‐epoxy‐6‐methyl‐triglycidyl‐3,4,5‐cyclohexanetricarboxylate (EGCHC) synthesized from sorbic acid, maleic anhydride, and allyl alcohol is proposed. Using commodity chemicals, a bio‐based carbon content of 68.4 % for the EGCHC resin is achieved. When cured with amine hardeners, the high oxirane content of EGCHC forms stiff cross‐linked networks with strong mechanical and thermal properties. The characterization of the epoxy specimens showed that EGCHC can compete with conventional epoxy resins such as DGEBA. A maximum stiffness of 3965 MPa, tensile strength of 76 MPa, and Tg of 130 °C can be obtained by curing EGCHC with isophorone diamine (IPD). The cured resin showed to be decomposable under mild conditions due to the ester bonds. The solid material properties of EGCHC expose its potential as a promising bisphenol A, and epichlorohydrine free alternative to conventional petroleum‐based epoxies with an overall high bio‐based carbon content. [ABSTRACT FROM AUTHOR]

A new synthesis route different from convenient epoxy/CO2 method was established to synthesize a five‐membered dicyclocarbonate of bisphenol A (BisA‐5dCC), and its hybrid non‐isocyanate polyurethanes with epoxy resins (HNIPUs) were reported. Bisphenol A was first reacted with 3‐chloro‐1,2‐propanediol to prepare a bisphenol A tetraol (BisA‐4OH), and then was reacted with excess diethyl carbonate to obtain BisA‐5dCC. Three polyhydroxyurethanes with H2N‐terminal groups (PHUs) were synthesized from the aminolysis polyaddition of BisA‐5dCC and excess hexanediamine. The PHUs were crosslinked with 1,4‐butanediol diglycidyl ether and bisphenol A diglycidyl ether, respectively, and different HNIPUs were prepared. The structures of BisA‐4OH, BisA‐5dCC, and PHUs were confirmed, and the HNIPUs were characterized by Fourier transform infrared, differential scanning calorimetry, dynamic mechanical analysis, thermogravimetric analysis, and tensile tests. HNIPUs prepared from aromatic epoxy showed higher Tg (up to 81°C) and better tensile strength (as high as 60 MPa) than those from aliphatic epoxy. High‐performance HNIPUs with excellent thermal and mechanical properties were successfully synthesized. Highlights: Dicyclocarbonate of bisphenol A (BisA‐5dCC) was prepared from a BisA tetraol.H2N‐terminated PHUs were synthesized further from the aminolysis of BisA‐5dCC.Hybrid non‐isocyanate polyurethanes (HNIPUs) were obtained from PHUs and epoxys.HNIPUs prepared from aromatic epoxy showed high Tg up to 81°C.They showed excellent tensile strength as high as 60 MPa. [ABSTRACT FROM AUTHOR]

Chemicals with high manufacturing volumes, such as bisphenol A (BPA), find widespread use in thermal paper, epoxy resins, and polycarbonate plastics. However, due to its endocrine-disrupting properties, several consumer items have restricted or banned its use. As a result, BPA has been replaced by other chemical substances with similar structures in consumer goods. This study aims to enhance and validate a chromatographic method for detecting BPA in baby bottles using chemometrics tools. A Box-Behnken experimental design was employed to optimize the laboratory conditions for the maximum release of BPA through forced degradation. The study utilized three parameters as independent variables, including incubation temperature (35 °C, 40 °C, and 60 °C), time (12 hours, 24 hours, and 36 hours), and solvent acetic acid concentration (2 %, 3 %, and 4 %). A second-order polynomial model was proposed, and a total of 15 experiments with two replicates were conducted to determine the optimal extraction conditions. The high-performance liquid chromatography (HPLC) partitioning method was used to determine peak areas of the different extracts, serving as responses. By applying the individual desirability approach, the optimal extraction conditions were found to be a temperature of 35 °C, an extraction time of 36 hours, and an acetic acid concentration of 4 % (pH = 2.72). The method was validated according to the conditions recommended by the International Conference on Harmonization (ICH) and SFSTP (Société Française des Sciences et Techniques Pharmaceutiques), ensuring high linearity, accuracy, precision, sensitivity, and robustness compared to existing liquid chromatographic methods. The improved method was applied to assess BPA levels in commercially available baby bottles, with 3 out of 7 samples testing positive for BPA, ranging from 0.615 ppb to 3.802 ppb. Notably, the enhanced method demonstrated a 12 % increase in yield compared to the ISO EN 14350-2:2004 method. This study provides a reliable and effective approach for detecting BPA in baby bottles, addressing critical concerns related to consumer safety and regulatory compliance. [ABSTRACT FROM AUTHOR]

In this study, bisphenol A‐type epoxy (ER) and epoxy phenol novolac resins (EPN) with two amine‐type curing agents (KH 816 and IPOX EH 2041) having different total amine values were selected. The mechanical properties and density of the EPN resin were found higher in the case of both curing agents. EPN was modified with polystyrene (EPN‐PS) and used as a matrix using an IPOX hardener. Nano‐ and hybrid composites were prepared with pristine and modified with tetramethylammonium chloride nano montmorillonite (NC and MNC), and red mud waste (RMW). The chemical structure was elucidated by the Fourier transform infrared (FT‐IR). The composites were characterized by scanning electron microscopy and x‐ray diffraction. Appropriate PS and NC ratio was accepted as 4% and 2% by weight, respectively. Curing degrees calculated from the FT‐IR spectra of ER, EPN, and EPN‐PS were 99.3%, 99.9%, and 86.5%, respectively. A comparative study of the two binary systems; (i) 2 wt% NC‐(15–35) wt% RMW; and (ii) 2 wt% of MNC‐(15–35) wt% of RMW on the mechanical, thermal, and flammability properties of EPN‐PS matrix was carried out. The appropriate RMW ratio was 30 wt%. Hybrid composites with 25–30 wt% RMW can be considered self‐extinguishing materials. [ABSTRACT FROM AUTHOR]

• The pyrolysis characteristics and components separation of EWTB were studied. • OER decomposition was a diffusion-controlled single-step reaction process. • Fixed-bed pyrolysis temperature range of EWTB was verified 400 ∼ 600 °C. • Bisphenol A in pyrolytic liquids could be recovered for epoxy resin synthesis. • The OER and the inorganic fiberglass were almost completely separated at 550 °C. After the peak of rapid wind power development, a large amount of wind turbine blades reach/exceed their service life due to aging or damage. These ex-service wind turbine blades (EWTB) will increase the issue of its high-efficient utilization in the future decades. Among several treatment methods, pyrolysis has been considered as a promising solution to separate inorganic fiberglass and make organic epoxy resin (OER) high-value-added converted. However, the pyrolysis mechanism, chemical composition, and fiberglass separation of EWTB have not been deeply studied. In this paper, the synthetic model compound of epoxy resin was firstly used to investigate the thermal weight loss and pyrolysis kinetics, the thermal weight loss temperature range of which was 300 ∼ 480 °C. The apparent activation energy was minimum when the conversion rate was 0.6, and the pyrolysis mechanism was determined by the Coats-Redfern method as a diffusion control. On this basis, a lab-scale fixed-bed was conducted to study fast-heating pyrolysis characteristics of EWTB. It could be analyzed that the chemicals in the pyrolytic liquid were a series of phenolics with methyl and vinyl substituted benzene rings (e.g., bisphenol A, p-isopropenyl phenol, and phenol). Bisphenol A presented a relatively high selectivity of 51.02%, which could be recycled as the main raw material for the synthesis of epoxy resins. Furthermore, clean fiberglass could be separated by combusting the residual carbon in pyrolytic solids. These results might be useful for achieving the separation and resource utilization of organic and inorganic components of EWTB. [ABSTRACT FROM AUTHOR]

Simple Summary: Endocrine disruptors are substances with a capacity to alter the endocrine system, one of the best known being bisphenol A. Bisphenol A is employed in the manufacture of a multitude of utensils used daily, and it is constantly being found polluting the environment and food. It is also an important aquatic pollutant, and its presence has been detected in coastal areas, rivers, and streams, among others. Due to its ubiquity, human and animal populations are frequently exposed to this compound. This work has compiled the effects on health of this substance, which are highly varied and are relevant in affecting reproduction and causing metabolic or immune system alterations, among others, as well as related to an increase in hormone-dependent pathologies, obesity, or type 2 diabetes. Monitoring the populations at risk and establishing a safe exposure level are proposed as being fundamental points in the control of exposure to this compound. Bisphenol A (BPA) is a chemical compound, considered as an "emerging pollutant", that appears ubiquitously, contaminating the environment and food. It is an endocrine disruptor, found in a multitude of consumer products, as it is a constituent of polycarbonate used in the manufacture of plastics and epoxy resins. Many studies have evaluated the effects of BPA, using a wide range of doses and animal models. In this work, we carried out a review of relevant research related to the effects of BPA on health, through studies performed at different doses, in different animal models, and in human monitoring studies. Numerous effects of BPA on health have been described; in different animal species, it has been reported that it interferes with fertility in both females and males and causes alterations in their offspring, as well as being associated with an increase in hormone-dependent pathologies. Similarly, exposure to BPA has been related to other diseases of great relevance in public health such as obesity, hypertension, diabetes, or neurodevelopmental disorders. Its ubiquity and nonmonotonic behavior, triggering effects at exposure levels considered "safe", make it especially relevant when both animal and human populations are constantly and inadvertently exposed to this compound. Its effects at low exposure levels make it essential to establish safe exposure levels, and research into the effects of BPA must continue and be focused from a "One Health" perspective to take into account all the factors that could intervene in the development of a disease in any exposed organism. [ABSTRACT FROM AUTHOR]

Bisphenol A (BPA) is commonly used for the manufacturing of plastic wares and epoxy resins, which both play vital roles in our daily life. The discovery of BPA has a tremendous beneficial effect, however, it has been discovered that BPA is a potent environmental endocrine disruptor to which persistent exposure has a negative impact on the metabolic, reproductive, and developmental processes which ultimately leads to diseases in humans and other organisms. Though, the numerous health issues associated with exposure to BPA are multifaceted and contentious. However, as humans rely heavily on plastics for day-to-day needs there are huge worries about the environmentally friendly nature of these plastics and the long-term consequence on human health. Exposure to BPA is a worldwide challenge and it has been detected in both the urine and serum of humans. The negative effects associated with exposure to BPA can be short-term or long-term. The focus is on scientists to do their research thoroughly to provide solutions and suggestions on how to prevent or minimize the life-threatening effect of BPA. The review aims to focus on the usage, incidence, and negative effects of BPA in humans and animals using available information within the last 10 years and to recommend steps to take toward minimizing exposure. [ABSTRACT FROM AUTHOR]

Bisphenol A (BPA), a chemical additive in polycarbonate plastics and epoxy resins, is suspected to be an endocrine‐disrupter. Extensive use and irregular treating methods have led to frequent detection of BPA in wastewater, raising demand for their removal by efficient nanomaterials‐based technique. Nanocomposite CuO@NiHCF was synthesized via green method using Citrus aurantium peel extract. Crystalline structure (particle size <50 nm) of CuO@NiHCF was analysed by microscopic and spectroscopic analysis. This nanocomposite showed 97% degradation of BPA (50 mg L−1) at neutral pH in sunlight. Moreover, improved particle stability (zeta potential: −56.2 mV; 2.0 eV) and high surface area, pore volume (81 m2g−1, 13.9 nm) resulted from synergism of NiHCF (−26.3 mV; 2.4 eV), and CuO (−11.5 mV; 1.9 eV) led to efficient photodegradation of BPA. Degradation of BPA was found photo‐adsorptive. Moreover, degradation was carried out by OH radicals based with ring‐opening mechanisms by GC–MS. High efficiency and sustainability of CuO@NiHCF were revealed by its multiple reusability (n = 10), leading to a promising and sustainable photocatalyst. [ABSTRACT FROM AUTHOR]

Effect of urea derivatives (UDs) on volume shrinkage during the curing of bisphenol A diglycidyl ether (BAGE)/bisphenol E cyanate ester (DCBE)/thermal latent polymeric hardener based on phenol‐amine salt (PAH) was investigated. The UDs with NH bonds and bulky substituents reduced the volume shrinkage effectively. The UDs were just dispersed in the compositions before the curing, whereas the UDs dissolved in the cured compounds by the collapse of the dense packing of UDs based on hydrogen‐bonding interaction and/or π‐stacking after the curing. Besides, the curing behavior and the structure of cured materials were examined by DSC and IR. The results revealed that the UDs hardly affected the curing of the DCBE/BAGE/PAH system. [ABSTRACT FROM AUTHOR]

Bisphenol A (BPA) is commonly used for the manufacturing of plastic wares and epoxy resins, which both play vital roles in our daily life. The discovery of BPA has a tremendous beneficial effect, however, it has been discovered that BPA is a potent environmental endocrine disruptor to which persistent exposure has a negative impact on the metabolic, reproductive, and developmental processes which ultimately leads to diseases in humans and other organisms. Though, the numerous health issues associated with exposure to BPA are multifaceted and contentious. However, as humans rely heavily on plastics for day-to-day needs there are huge worries about the environmentally friendly nature of these plastics and the long-term consequence on human health. Exposure to BPA is a worldwide challenge and it has been detected in both the urine and serum of humans. The negative effects associated with exposure to BPA can be short-term or long-term. The focus is on scientists to do their research thoroughly to provide solutions and suggestions on how to prevent or minimize the life-threatening effect of BPA. The review aims to focus on the usage, incidence, and negative effects of BPA in humans and animals using available information within the last 10 years and to recommend steps to take toward minimizing exposure.

Bisphenol A (BPA) is a ubiquitous synthetic compound used as a monomer in the production of polycarbonate plastics and epoxy resins. Even at low doses, BPA has been associated with the molecular progression of diseases such as obesity, metabolic syndrome, and hormone-regulated cancers due to its activity as an endocrine-disrupting chemical (EDC). Consequently, the use of BPA has been regulated worldwide by different health agencies. BPA structural analogs such as bisphenol S and bisphenol F (BPS and BPF) have emerged as industrial alternatives, but their biological activity in the molecular progression of cancer remains unclear. Prostate cancer (PCa) is a hormone-dependent cancer, and the role of BPA structural analogs in PCa progression is still undescribed. In this work, we use an in vitro model to characterize the transcriptomic effect of low-concentration exposure to bisphenol A, S, or F in the two main stages of the disease: androgen dependency (LNCaP) and resistance (PC-3). Our findings demonstrated that the low concentration exposure to each bisphenol induced a differential effect over PCa cell lines, which marks the relevance of studying the effect of EDC compounds through all the stages of the disease. [ABSTRACT FROM AUTHOR]

Bisphenol A (BPA) is a monomer commonly used in the production of epoxy resins, plastic bottles and dental filling materials. Due to its chemical structure, BPA and its derivates show activity similar to the endocrine hormones. It can bind to estrogen receptors and cause neurological disturbances, even at low doses. Therefore, it is important to determine BPA and its derivatives quickly and sensitively at low concentrations. In this study, a single amperometric tyrosinase enzyme biosensor was designed for the determination of the amount of BPA, bisphenol F (BPF) and bisphenol S (BPS) monomers. Tyrosinase was immobilized onto a modified carbon paste electrode by cross-linking with glutaraldehyde. The amount of BPA (BPS and BPF) was determined directly on the reduction of quinone compound released as a result of the enzymatic reaction at -0.15V. Km(app) value of the designed biosensor for BPA was found 0.00067 μM, the linear operating range was 0.001-0.005 μM (a) and 0.03-0.1 μM (b) and the lower detection limit was found 1 nM for each monomer. It is clear that designed biosensor enable the fast, efficient and precise determination of BPA and its derivatives released from materials used in dental materials. [ABSTRACT FROM AUTHOR]

Epoxy resins are widely used in a variety of application fields, thanks to their good mechanical strength, chemical resistance and adhesion to several substrates. Nowadays, the quite majority of epoxy resins are based on derivatives of bisphenol A (BPA), which poses serious health concerns. This issue is pushing the research towards suitable bio-based alternatives to this product, being furan-based epoxies very promising in this respect. In a previous work, 2,5-bis[(oxiran-2-ylmethoxy)methyl]furan (BOMF) was cured with methyl nadic anhydride (MNA), and successfully used as tinplate coating. Herein, in a view of increasing the sustainability of these epoxy resins, we have replaced MNA with maleic anhydride (MA), which can be derived from vegetable feedstocks, thus obtaining a fully bio-based epoxy resin. This latter has then been used as adhesive for carbon fiber-reinforced thermosetting plastics (CFRP). The curing process of the resin was monitored by differential scanning calorimetry (DSC) and chemo-rheological analysis. The results highlighted the significantly higher reactivity of BOMF towards MA compared to the diglycidyl ether of BPA (DGEBA). The crosslinked samples were characterized in their thermal, mechanical and adhesive properties. In comparison to DGEBA/MA and BOMF/MNA, BOMF/MA showed higher ultimate strain and slightly lower glass transition temperature, tensile modulus and ultimate strength. Interestingly, BOMF/MA displayed outstanding adhesive strength on CFRP joints, outperforming the DGEBA-based counterpart by three times. Indeed, by properly selecting the anhydride curing agent, a highly ductile fully bio-based material was developed for high performance adhesive applications. The overall results demonstrate that the properties of BOMF-based epoxy resins can be tailored to meet technical and safety requirements of downstream applications, representing a sustainable alternative to traditional systems containing DGEBA. [ABSTRACT FROM AUTHOR]

Bisphenol A, a toxic chemical, is widely used in the preparation of epoxy resins. Therefore, the use of harmless biomass-based raw materials to replace bisphenol A in the preparation of epoxy resin has attracted extensive attention. A demethylated-lignin-based epoxy resin adhesive was prepared. After lignin was modified in a LiBr/HBr system, the phenolic hydroxyl group content of the obtained demethylation lignin (DL) increased to 6.19 mmol g−1, and the tensile strength of the as-prepared DL-modified adhesive (–OH content of the DL = 6.19 mmol g−1) increased to 62.50 MPa, which was much higher than the adhesive modified by raw lignin (38.89 MPa). Due to its excellent crosslinking density, the DL-modified adhesive retained more than 85% of its tensile shear strength performance after being soaked in water for 48 h or frozen at −25 °C for 48 h. Therefore, this adhesive has a wide range of application prospects in furniture and plywood manufacturing. [ABSTRACT FROM AUTHOR]

Products used in daily life contain multiple chemicals capable of inducing endocrine disruption in animals, including humans. One such typical substance is bisphenol A (BPA). BPA has been widely used in epoxy resins and polycarbonate plastics and can exert several adverse effects. Further - more, given their structural similarity to BPA, phenolic analogs of BPA, i.e., synthetic phenolic antioxidants (SPAs), are considered to exhibit similar toxicity; however, the effects of early SPA exposure on the adult central nervous system remain poorly clarified. In the present study, we aimed to evaluate and com- pare the neurobehavioral effects of early life exposure to BPA and two selected SPAs, 4,4'-butylideneb- is (6-tert-butyl-m-cresol) (BB) and 2,2'-methylenebis (6-tert-butyl-p-cresol) (MB). We exposed mice to low levels of these chemicals through drinking water during prenatal and postnatal periods. Subsequently, we examined the adverse effects of these chemicals on the central nervous system using a mouse behavioral test battery, comprising the open field test, light/dark transition test, elevated plus-maze test, contextual/cued fear conditioning test, and prepulse inhibition test, at 12-13 weeks old. Based on the behavioral analysis, SPAs, like BPA, may cause affective disorders even at low doses, although qualitative differences were noted in anxiety-related behaviors. In conclusion, our findings could be valuable for clarifying the potential adverse developmental risks of SPA exposure in early life. [ABSTRACT FROM AUTHOR]

Four siloxane benzoxazines containing different rigid segments were successfully synthesized and characterized herein, including a benzene ring, a biphenyl, a naphthalene ring, and a diphenyl sulfone group. Different rigid segments had different effects on polymer properties. The introduction of the naphthalene ring and sulfone group considerably reduced the curing temperature of benzoxazine. Although the benzoxazine with the naphthalene ring exhibited low heat resistance, all the four samples showed a high char yield at 800°C under nitrogen atmosphere. In addition, during copolymerization with AG-80 epoxy, the introduction of epoxy promoted the curing of the benzoxazines containing the naphthalene ring and sulfone group. The heat resistance of all copolymers was considerably improved, especially for the copolymer containing the naphthalene ring, whose 5% thermal weight loss temperature (T d5) increased from 248°C to 321°C under nitrogen atmosphere. The copolymer containing the biphenyl structure had the highest glass transition temperature, reaching 259.1°C. Copolymerization with epoxy also considerably improved the tensile strength and elongation at break of the copolymers, which were much higher than those of traditional bisphenol A-aniline based benzoxazine (BA-a). Compared with the neat benzoxazine prepared using siloxane and bisphenol A, the developed copolymers also had better tensile properties, and the copolymer containing the sulfone group showed the greatest improvement (from 49 to 69 MPa, from 3.1% to 9.12%). [ABSTRACT FROM AUTHOR]

A thermosetting epoxy polymer composed of diglycidyl ether of bisphenol A and triethylenetetramine (DGEBA/TETA) was modified by incorporating flexographic photopolymer plate residues (rubber microparticles). The photopolymer plate residues were processed in two ways: (a) by grinding and performing particle size classification (where the resulting samples were denoted PP) and (b) by polyester layer separation and grinding the elastomeric fraction by cryogenic grinding (where the resulting samples were denoted ER). Both residual particles were incorporated into the epoxy at concentrations of 2.5, 5 and 7.5 wt%. The main results indicate that PP was not efficient as a modifier of the epoxy system. A reduction in mechanical properties (maximum tensile strength and deformation) was observed in the samples produced with PP in different concentrations. But, when the ER is incorporated, an increase in tensile property and in the deformation capacity, as well as impact resistance was observed in samples produced with ER. Scanning electron microscopy analysis showed a greater presence of voids in formulations produced with PP, which corroborates the decrease in the tensile strength of these samples. [ABSTRACT FROM AUTHOR]

Spent coffee waste (CW) was used as a reinforcement in the bisphenol A-type epoxy resin. Various methods such as alkali (NaOH), microwave (MW), ultrasound (US), and alkali pretreatment followed by microwave (NaOH-MW) treatments were applied for CW filler. For the characterization of CW, Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM)/energy-dispersive X-ray spectroscopy (EDX) were used. The composites were characterized by SEM, mechanical, thermal, water sorption, and contact angle measurement analyses. The effects of treatment methods and filler ratios on the properties of epoxy composites were investigated. The highest tensile strength (81–106 MPa) for composites was found with NaOH-CW filler, while the highest decrease in thermal values was determined in the (NaOH + MW)-CW composites. Water sorption of composites which is affected by treatment methods of CW increased with filler loading in all composites. The best results were obtained for with MW-CW composites water absorption and wettability properties. [ABSTRACT FROM AUTHOR]

Polycarbonate plastics for packaging and epoxy resins are both made with the industrial chemical bisphenol A (BPA). This investigation looked at the histological structure, antioxidant enzymes, and albino rats' testis to determine how coenzyme Q10 (CoQ10) impacts BPA toxicity. For the experiments, three sets of 18 male adult rats were created: group 1 received no therapy, group 2 acquired BPA, and group 3 got the daily BPA treatment accompanied by coenzyme Q10, 1 h apart. The experimental period ran for 14 days. The biochemical biomarkers catalase (CAT), superoxide dismutase (SOD), and malondialdehyde (MDA) were altered as a result of BPA exposure. The testicular histological architecture, which is made up of apoptosis, was also exaggerated. Furthermore, rats given BPA and CoQ10 treatment may experience a diminution in these negative BPA effects. These protective properties of CoQ10 may be correlated with the ability to eliminate oxidizing substances that can harm living species. The outcomes might support the hypothesis that CoQ10 prevented oxidative damage and boosted rats' stress responses when BPA was introduced. Thus, by shielding mammals from oxidative stress, CoQ10 aids in the growth and development of the animals. BPA is extremely hazardous to humans and can persist in tissues. Human reproductive functions are a worry due to human exposure to BPA, especially for occupational workers who are typically exposed to higher doses of BPA. As a result, in order to reduce the health risks, BPA usage must be minimized across a diverse range of industries, and improper plastic container handling must be prohibited. By giving CoQ10 to patients, BPA's harmful effects on reproductive structures and functions may be avoided. [ABSTRACT FROM AUTHOR]

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Carbon fiber (CF) is widely used in the preparation of carbon-fiber-reinforced polymer composites (CFRP) in which it is combined with epoxy resin due to its good mechanical properties. Thermosetting bisphenol A epoxy resin, as one of the most common polymer materials, is a non-renewable resource, leading to a heavy environmental burden and resource waste. To solve the above problems and achieve high mechanical and thermal properties comparable to those of bisphenol A, herein, a high-performance, degradable and recyclable bio-based epoxy resin was developed by reacting the lignin derivative vanillin with 4-amino cyclohexanol via Schiff base. This bio-based epoxy resin showed a Young's modulus of 2.68 GPa and tensile strength of 44 MPa, 36.8% and 15.8% higher than those of bisphenol A epoxy, respectively. Based on the reversible exchange reaction of the imine bond, the resin exhibited good degradation in an acidic environment and was recoverable by heat treatment. Moreover, the prepared epoxy resin could be used to prepare carbon fiber (CF)-reinforced composites. By washing off the epoxy resin, the carbon fiber could be completely recycled. The recovered carbon fiber was well preserved and could be used again for the preparation of composite materials to realize the complete recovery and utilization of carbon fiber. This study opens a way for the preparation of high-performance epoxy resin and the effective recycling of carbon fiber. [ABSTRACT FROM AUTHOR]

Epoxy resins are among the best performing adhesives. Recovering the adhesively joined parts for repetitive use demands innovative bonding strategies to afford facile debonding while not sacrificing the adhesion performance. Here, a series of hardeners were prepared by reacting elemental sulfur with renewable 10-undecenoic acid and further employed for curing diglycidyl ether of bisphenol-A (DGEBA). Dynamically cross-linked epoxy networks from this solvent- and catalyst-free procedure exhibit high tensile strength and toughness, which are well maintained during repetitive thermal processing, assisted by exchanges of the S–S bonds and β-hydroxyl ester moieties. Moreover, the toughened epoxy resins show a high adhesion strength of up to 31 MPa for steel plates. Furthermore, the joined plates can be readily separated by immersing in a methanol solution of Na2S or hexylamine without any residual resins. [ABSTRACT FROM AUTHOR]

Bisphenol A (4,4-isopropylidenediphenol, BPA) is an organic compound widely used, e.g., in the production of epoxy resins, plastics, and thermal receipt papers. Unfortunately, bisphenol A has negative effects on human health, which has prompted the search for an effective method of its removal. One of the most promising methods of its elimination is photocatalytic removal. The aim of this study was to design an effective method for the photocatalytic removal of bisphenol A using, for the first time, hierarchical zeolites and ruthenium ion-modified diatom biosilica, and silver as photocatalysts and optimization of the reaction conditions: temperature, pH, and composition of the reaction mixture as well as the electromagnetic wavelength. Additionally, for the first time, the electromagnetic wavelength that would be most suitable for the study was selected. All materials used were initially characterized by XRD and low-temperature nitrogen adsorption/desorption isotherms. Ruthenium ion-modified biosilica proved to be the most effective catalyst for bisphenol A removal, which occurred at a rate higher than 99%. [ABSTRACT FROM AUTHOR]

Bisphenol A (BPA) is one of the most widely produced chemicals in the world used in the production of epoxy resins and polycarbonate plastics. BPA is easily migrated from the outer packaging to the contents. Due to the lipophilic property, BPA is easily accumulated in organisms. Perinatal low-dose BPA exposure alters brain neural development in later generations. In this study, after BPA treatment, the spontaneous movement of zebrafish larvae from the cleavage period to the segmentation period (1–24 hpf) was significantly decreased, with speed decreasing by 18.97% and distance decreasing between 18.4 and 29.7% compared to controls. Transcriptomics analysis showed that 131 genes were significantly differentially expressed in the exposed group during the 1–24 hpf period, among which 39 genes were significantly upregulated and 92 genes were significantly downregulated. The GO enrichment analysis, gene function analysis and real-time quantitative PCR of differentially expressed genes showed that the mRNA level of guanine deaminase (cypin) decreased significantly in the 1–24 hpf period. Moreover, during the 1–24 hpf period, BPA exposure reduced guanine deaminase activity. Therefore, we confirmed that cypin is a key sensitive gene for BPA during this period. Finally, the cypin mRNA microinjection verified that the cypin level of zebrafish larvae was restored, leading to the restoration of the locomotor activity. Taken together, the current results show that the sensitive period of BPA to zebrafish embryos is from the cleavage period to the segmentation period (1–24 hpf), and cypin is a potential target for BPA-induced neurodevelopmental toxicity. This study provides a potential sensitive period and a potential target for the deep understanding of neurodevelopmental toxicity mechanisms caused by BPA. [ABSTRACT FROM AUTHOR]

Surface-Enhanced Raman Spectroscopy (SERS) was employed as a spectroscopic tool to detect Bisphenol A (BPA), a building block in polycarbonate and epoxy resins or an additive in other polymer plastics like PVC, which has an endocrine disruptor effect. Silver nanoparticles (AgNPs) synthesized by using different reducing agents such as hydroxylamine (Ag@HX), citrate (Ag@Cit), borohydride (Ag@BH), and β-cyclodextrin (Ag@βCD) were employed, aiming to select the best standard SERS substrate. The lowest limit of quantification was reached at a concentration of 0.01 mM (2.3 μg/mL) of a sonicated aqueous solution by using Ag@Cit NPs and identifying two enhanced bands recorded at about 350 and 460 cm−1. In order to gain insight into the nature of the enhanced bands, and therefore into which mechanism governs the SERS signal, electrochemical spectra recorded at different electrode potentials were acquired and TD-DFT calculations were applied to a neutral silver complex of BPA, Ag2-BPA, and to its monohydroxylated chemical specie, Ag2-BPA(OH), which is present in sonicated solution. The calculated electronic structure and the resonance Raman spectra point out that a surface plasmon-like resonance inside the silver cluster dominates the SERS spectrum corresponding to the physisorbed BPA(OH) species, a charge transfer enhancement mechanism or an intramolecular resonance transition localized in the phenolic framework was then discarded. [ABSTRACT FROM AUTHOR]