Monomer Bisphenol Research Articles

Bisphenol S, a Bisphenol A alternative, impairs swine ovarian and adipose cell functions

The high-volume-produced plastic monomer Bisphenol A (BPA) has been in the spotlight in the last years because of its endocrine disruptor (ED) behavior, leading to disclosure of the association between the widespread human and wildlife exposure to BPA and reproductive, metabolic, and developmental disorders and hormone-dependent cancer onset. These evidences caused restrictions and prohibitions of BPA industrial uses and prompted investigation of harmless alternative compounds. Above all, several countries have substituted the parental analogue with Bisphenol S (BPS) in baby care product manufacturing, even if its structural homology to BPA suggests similar ED properties not yet completely ruled out. In light of this consideration, the aim of this in vitro study was to investigate the effect of BPS exposure (0.1, 1, and 10 μM for 48 h) on granulosa cells that are considered the prime ovarian targets of BPA as a “reproductive toxicant”. Our data document that BPS inhibited E2 production, cell proliferation, and scavenging nonenzymatic activity (P < 0.05) while it significantly (P < 0.05) stimulated cell viability, superoxide (O2−) and nitric oxide (NO) production in cultured swine granulosa cells, a previously validated endocrine cell model for BPA. Evidence also exists that BPA and its analogues, as environmental lipophilic pollutants, are involved in the disruption of adipose tissue (AT) endocrine function, resulting in metabolic effects and thus in potential reproductive disorders. On this basis, our second purpose was the assessment of BPS effects on mesenchymal stromal cells (MSCs) isolated from porcine AT, taking into account MSCs viability and adipogenic differentiation, a process actually demonstrated to be largely affected by EDs. Our results show that BPS decreased (P < 0.001) cell viability of proliferating adipose stromal cells. Taken as a whole, our data demonstrate an effective BPS ED activity at μM concentrations, suggesting that further studies are needed before considering its use in industrial application as an alternative to BPA.

Chemical Recycling of Poly(bisphenol A carbonate) by Glycolysis under 1,8-Diazabicyclo[5.4.0]undec-7-ene Catalysis.

The glycolysis reaction of poly(bisphenol A carbonate) (PC) has been explored under 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) catalysis as a potential route to valorize PC wastes by chemical recycling. The amidine base is an active catalyst of PC glycolysis and, under suitable conditions, promotes effectively and selectively the depolymerization of the polymeric material with 1,2-propanediol or glycerol to give the monomer bisphenol A (BPA) and the relevant cyclic carbonate. The depolymerization process has been investigated under solventless conditions, using diol/triol as the reagent and reaction medium, and also in an auxiliary solvent such as tetrahydrofuran (THF) that is able to dissolve the polymer. The influence of a few experimental parameters (temperature, catalyst load, and reaction time) on the selectivity to cyclic carbonate has been studied. High selectivity to cyclic carbonate has been attained by carrying out the depolymerization reaction in THF and using mild temperature conditions and a stoichiometric amount of polyol. The catalyst can be recovered from the reaction mixture as a BPA/DBU adduct and effectively recycled in a successive run.

Densely quaternized anion exchange membranes synthesized from Ullmann coupling extension of ionic segments for vanadium redox flow batteries

Membranes with high ion conductivity and selectivity are important for vanadium redox flow batteries. Herein, densely quaternized anion exchange membranes based on quaternary ammonium functionalized octa-benzylmethyl-containing poly(fluorenyl ether ketone)s (QA-OMPFEKs) were prepared from the (i) condensation polymerization of a newly developed octa-benzylmethyl-containing bisphenol monomer via Ullmann coupling, (ii) bromination at the benzylmethyl sites using N-bromosuccinimide, and (iii) quaternization of the bromomethyl groups using trimethylamine. The QA-OMPFEK-20 with an ion exchange capacity (IEC) of 1.66 mmol g−1 exhibited a higher SO42− conductivity (9.62 mS cm−1) than that of the QA-TMPFEK-40 (4.82 mS cm−1) at room temperature, which had a slightly higher IEC of 1.73 mmol g−1 but much lower QA density. The enhanced SO42− conductivity of QA-OMPFEK-20 was attributed to the ion-segregated structure arising from the densely anchored QA groups, which was validated by SAXS observation. Furthermore, the QA-OMPFEK-20 showed much lower VO2+ permeability (1.24×10−14 m2 s−1) than QA-TMPFEK-40 (5.40×10−13 m2 s−1) and Nafion N212 (5.36×10−12 m2 s−1), leading to improved Coulombic and energy efficiencies in Vanadium redox flow batteries (VRFBs). Therefore, the Ullmann coupling extension is a valuable approach for the development of high performance anion exchange membranes for VRFBs.

High‐performance composite nanofiltration membranes fabricated via ternary mixture: Complementary preponderance of the fluorine‐containing monomer 2,2′‐bis(1‐hydroxyl‐1‐trifluoromethyl‐2,2,2‐triflutoethyl)‐4,4′‐methylene dianiline and the rigid monomer bisphenol F

ABSTRACTIn a previous study, we proved that tailoring the polyamide backbone stiffness is an effective way to fabricate high‐performance polyamide nanofiltration (NF) membranes. However, in the previous study, we mainly focused on the flat membrane and did not consider its chlorine tolerance. In this study, by regulating the aqueous‐phase compositions in the interfacial polymerization process, chlorine tolerance on NF hollow‐fiber membranes was endowed while the membrane performance stayed high. The experimental results show that when the ratio of Piperazine (PIP)–bisphenol F (BPF)/2,2′‐bis(1‐hydroxyl‐1‐trifluoromethyl‐2,2,2‐triflutoethyl)‐4,4′‐methylene dianiline (BHTTM) was 5:1:4, the NF membrane possessed a permeate flux of 21.0 L m−2 h−1 bar−1 and an Na2SO4 rejection up to 90.0%. X‐ray photoelectron spectroscopy analysis also confirmed that the polymerization degree of the PIP–BPF–BHTTM NF membrane was the highest. Moreover, the NF membrane could tolerate active chlorine to over 10,000 ppm h Cl. After the active chlorine treatment, the permeate flux increased over 30.0 L m−2 h−1 bar−1, and the Na2SO4 rejection was about 90.0%. Although the PIP–BHTTM NF membrane also possessed good chlorine tolerance, its permeate flux (after active chlorine treatment) was only 60% of that of the PIP–BPF–BHTTM NF membrane. Therefore, the PIP–BPF–BHTTM NF membrane possessed a combination of high flux and high chlorine tolerance and showed good potential in water treatment in rigorous environments. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46482.

Densely quaternized poly(arylene ether)s with distinct phase separation for highly anion-conductive membranes

To develop high performance anion exchange membranes (AEMs), a novel bisphenol monomer bearing eight benzylmethyl groups at the outer edge of the molecule was synthesized, which after condensation polymerization with various amounts of 4,4′-dihydroxydiphenylsulfone and 4,4′-difluorobenzophenone yielded novel poly(arylene ether)s with densely located benzylmethyl groups. These benzylmethyl groups were then converted to quaternary ammonium groups by radical-initiated bromination and quaternization in tandem, leading to the emergence of densely quaternized poly(arylene ether sulfone)s (QA-PAEs) with controlled ion exchange capacities (IECs) ranging from 1.61 to 2.32 mmol g−1. Both small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM) studies revealed distinct phase separation in the QA-PAEs. The QA-PAE-40 with an IEC of 2.32 mmol g−1 exhibited a Br− conductivity of 9.2 mS cm−1 and a SO42− conductivity of 14.0 mS cm−1 at room temperature, much higher than those of a control membrane with a similar IEC but without obvious phase separation. Therefore, phase separation of AEMs was validated to be advantageous for the efficient conducting of anions. The experimental results also showed that the QA-PAEs were promising AEM materials, especially for non-alkaline applications.

Pyrolysis mechanism and thermal degradation kinetics of poly(bisphenol A carbonate)-based polymers originating in waste electric and electronic equipment

Poly(bisphenol A carbonate) or polycarbonate (PC) constitutes a significant fraction of the Waste Electrical and Electronic Equipment, mainly due to its high production and consumption rate and its variety of applications. Traditional methods for its treatment no longer appear to provide long-term solutions and for this reason, the investigation of thermochemical methods and more specifically pyrolysis as a potential recycling method took place in the current study. In the first part of this study, pyrolysis studies of polycarbonate have been performed in a Pyrolizer equipped with GC–MS, at five different reactor temperatures, in order to facilitate the understanding of the degradation mechanism. Higher pyrolysis temperatures were found to be more suitable for PC pyrolysis, since they increased the volatile fractions (liquid and gaseous). The gaseous fraction consisted mainly of CO2, CH4 and CO, whereas in the liquid fraction a large amount of different phenolic compounds, including the monomer bisphenol A was recorded. Based on the findings, it has been suggested that the main degradation pathway follows a chain scission mechanism and that the scission of the isopropylidene linkage is the first step. Phenols and phenolic compounds were formed through a series of scission and hydrolysis reactions. In the second part, pyrolysis kinetics of PC are investigated in detail using thermogravimetric experimental data, collected at several heating rates and several either model-free (isoconversional) or model-fitting models. From the isoconversional kinetic analysis the effective activation energy was fund to increase with the extent of conversion, ranging from 146 to 189 kJ/mol and from 154 to 215 kJ/mol, when using the integral method of Tang (similar to the KAS) or the differential method of Friedman, respectively. A simple first order kinetic model was found to simulate excellent the experimental data, though predicting different activation energies and pre-exponential factors at each heating rate employed. The random scission and the autocatalytic models were investigated in detail and the best fit to the experimental data at all different heating rates was found to be the autocatalytic model with n = 1.15 and m = 0.46 (values close to those considered for the random scission model with L = 2, i.e. n = 1.119 and m = 0.4) using an average activation energy, E = 195.9 kJ/mol and pre-exponential factor A = 6.06 1012 min−1. Having a detailed knowledge of the PC degradation kinetics and mechanism will help in better design of large scale process for the recycling of such material originating in WEEE and provide targeted value-added products.

Preparation and cure kinetics of epoxy with nanodiamond modified with liquid crystalline epoxy

A novel epoxy composite with liquid crystalline epoxy resin modified nanodiamond (ND-LCER) was prepared by grafting diglycidyl ether of 4,4′-bisphenol (DGEBP) monomers onto the surface of acid treated nanodiamond (ND-COOH). Untreated nanodiamond (UND), ND-COOH and ND-LCER were composited with epoxy/4,4′-diamino diphenyl sulfone (DDS) in various weight ratios, respectively. The cure behavior of the prepared composite systems was investigated with dynamic differential scanning calorimetry (DSC) technology at different heating rates. The NDs exhibited acceleration effects on the curing reaction with increase of content amounts, which might attribute to the special structure of the nanodiamond (ND) particles itself and the functional groups of the ND. The modified ND particles showed the lowest activation energy value due to the diminution to the diffusion control process caused by liquid crystalline epoxy resins molecules. The two-parameter (m, n) autocatalytic model of Sestak-Berggren based on the Malek method is in-line with the epoxy/ND composites.

Urinary bisphenol A concentrations in relation to asthma in a sample of Egyptian children.

Bronchial asthma is one of the top disabling diseases in pediatrics. Limited research has been studied the association of the widely used plastic monomer bisphenol A (BPA) with childhood asthma. To compare the levels of urinary BPA in asthmatic and control children and to investigate the implication of BPA among other risk factors for the development of asthma. This case-control study included 97 children (45 asthmatic and 52 healthy controls) aged 3-8 years. Asthmatic children were diagnosed according to Global initiative for asthma (GINA) guidelines. Sociodemographic factors were assessed and urinary levels of BPA were determined in spot urine samples using high-performance liquid chromatography. The contribution of BPA among predictors for developing asthma was studied in asthmatic children. Median total urinary BPA levels were significantly higher in asthmatic children than in control group (1.56 ng/mL in asthmatic children compared to 0.790 ng/mL in control group, p = 0.001). Children who had total urinary BPA levels >1.3 ng/mL were more likely to be asthmatic (odds ratio: 2.84, 95% confidence interval 1.22-6.59, p = 0.015). Multiple logistic regression analysis for predictors of asthma showed the importance of higher levels of BPA (>1.3 ng/mL) as a more significant predictor than passive smoking ( p = 0.006 for BPA categories vs. p = 0.049 for passive smoking). Association of higher levels of urinary BPA with the diagnosis of asthma in children may indicate the potential risk of BPA exposure in the precipitation of bronchial asthma. Further clinical and biochemical research are needed to clarify the proper mechanism explaining this association.

BisGMA analogues as monomers and diluents for dental restorative composite materials

Current commercially available dental composite materials have certain limitations for their use, including high monomer viscosity and high polymerization shrinkage, resulting in residual stresses and interfacial gaps. This study focused on the chemical modification of resin monomer bisphenol A-glycidyl methacrylate (bisGMA), so as to reduce the viscosity and polymerization shrinkage. In this design, the hydroxyl groups of bisGMA were transformed into ester groups with various alkyl chain length and branching. The modified monomers showed promising properties including reduced viscosity, reduced polymerization shrinkage, increased hydrophobicity, increased degree of double bond conversion, and improved mechanical properties of the resulting dental resin composites. The structure/property relationships of the new monomers were investigated, and optimal monomer structures were identified for dental composites with improved properties.

Partially fluorinated poly(arylene ether)s bearing long alkyl sulfonate side chains for stable and highly conductive proton exchange membranes

Condensation polymerization of two diallyl-containing bisphenol monomers with decafluorobiphenyl catalyzed by CsF at low temperatures yielded quantitatively the diallyl-containing fluorinated poly(arylene ether)s, which after the thiol-ene click reaction with sodium 3-mercapto-1-propanesulfonate yielded sulfonated fluorinated poly(arylene ether)s (SFPAEs) with long alkyl sulfonate side-chains. The sulfonate groups were spaced by 7 atoms away from the aromatic backbone, in stark contrast to the previous reports where only 6 spacing atoms could be achieved using a similar chemistry but rather harsh reaction conditions. Two series of SFPAEs based on bisphenol A and bisphenol S units, respectively, were both found to exhibit distinct phase separation and enhanced proton conductivity. Specifically, the SFPAE-A-70 with an ion exchange capacity (IEC) of 1.62mmolg−1 exhibited an in-plane proton conductivity of 90mScm−1 at room temperature, which was slightly higher than that of Nafion 212. Furthermore, all of the SFPAEs showed significantly improved oxidative stability in Fenton's reagent when comparing to non-fluorinated analogs. This study offered a new strategy for the synthesis of highly branched ionomers with long and flexible aliphatic side-chains for high performance PEMs.

The effect of polyarylene ether nitriles structures on their foaming behaviors and dielectric properties of the films

Two kinds of polyarylene ether nitriles (PEN) with different molecular structures were designed and synthesized by two kinds of bisphenol monomers. Then, solution casting method has been used to obtain three kinds of films based on the two kinds of pure PEN and their blends with a weight ratio of 1:1. The chemical structures of PEN were characterized by Fourier transform infrared (FTIR). Dynamic rheology behaviors were investigated to study the effects of inherent structures on the motion of molecular chains. Then, three kinds of foamed PEN films were prepared with supercritical carbon dioxide foaming method and the micro-morphology were monitored by scanning electron microscopy (SEM). Results indicated that microcellular foam films were obtained and dielectric properties of the foamed PEN films exhibited significant difference from that of un-foamed films. The dielectric constant of micro-foamed film decreased to 2.0. Moreover, the unusual dielectric properties of two kinds of PEN composite film were discussed in detail, which can be ascribed to the fact of micro-phase separation.

Novel organosoluble polyarylates based on diphenylamine-fluorene units

Two kinds of polyarylates with diphenylamine-fluorene units were synthesized from the bisphenol monomer “ N, N-di(4-hydroxyphenyl)-2-amino-9,9-dimethylfluorene” with two different benzenedicarbonyl chlorides. These polyarylates were highly soluble in N, N-dimethylacetamide, tetrahydrofuran, and chloroform and could be easily solution-cast into transparent films. Both of the polyarylates exhibited a couple of reversible redox with half-wave potentials in the range of 0.87–0.90 V. During the electrochromic process, the color of the film changed from colorless (neutral state) to grey green (oxidation state) with a high coloration efficiency of 242 cm2 C−1. Compared with the polyarylates prepared from terephthaloyl chloride, the polyarylates prepared from isophthaloyl chloride exhibited enhanced fluorescence because of the reduced charge-transfer effect. Furthermore, its fluorescence could be reversibly switched under the applied potentials.

Highly proton conducting proton‐exchange membranes based on fluorinated poly(arylene ether ketone)s with octasulfonated segments

ABSTRACTA new bisphenol monomer containing a pair of electron‐rich tetra‐arylmethane units was designed and synthesized. Based on this monomer, along with commercial 4,4′‐(hexafluoroisopropylidene)diphenol A and 4,4′‐difluorobenzophenone, a series of novel poly(arylene ether ketone)s containing octasulfonated segments of varying molar percentage (x) (6F‐SPAEK‐x) were successfully synthesized by polycondensation reactions, followed by sulfonation. Tough, flexible, and transparent membranes, exhibiting excellent thermal stabilities and mechanical properties were obtained by casting. 6F‐SPAEK‐x samples exhibited appropriate water uptake and swelling ratios at moderate ion exchange capacities (IECs) and excellent proton conductivities. The highest proton conductivity (215 mS cm−1) is observed for hydrated 6F‐SPAEK‐15 (IEC = 1.68 meq g−1) at 100 °C, which is more than 1.5 times that of Nafion 117. Furthermore, the 6F‐SPAEK‐10 membrane exhibited comparable proton conductivity (102 mS cm−1) to that of Nafion 117 at 80 °C, with a relatively low IEC value (1.26 meq g−1). Even under 30% relative humidity, the 6F‐SPAEK‐20 membrane (2.06 meq g−1) showed adequate conductivity (2.1 mS cm−1) compared with Nafion 117 (3.4 mS cm−1). The excellent comprehensive properties of these membranes are attributed to well‐defined nanophase‐separated structures promoted by strong polarity differences between highly ionized and fluorinated hydrophobic segments. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 25–37

Preparation and characterization of novel zwitterionic poly(arylene ether sulfone) ultrafiltration membrane with good thermostability and excellent antifouling properties

Zwitterionic poly(arylene ether sulfone) (PAES-NS) was synthesized via copolymerization by using a bisphenol monomer with a pyridine group. The chemical structures of the copolymers were confirmed by using Fourier transform infrared (FTIR) and 1H nuclear magnetic resonance (NMR) spectroscopy; the copolymers showed good thermal stability. A series of polyphenysulfone (PPSU)/PAES-NS blend ultrafiltration (UF) membranes was prepared via conventional immersion precipitation phase inversion methods The morphologies of the modified membranes were investigated by scanning electron microscopy (SEM). The surface hydrophilicity of the UF membranes was studied by water contact angle measurement, indicating that the zwitterionic group increased the membrane hydrophilicity. UF of solvated model pollutants using the membranes showed a significant reduction of the irreversible adsorption of the foulants, illustrating the excellent anti-fouling properties of the membrane. The water flux of the PAES-NS membrane was significantly enhanced, being almost three times higher than that of the pristine PPSU membrane, with retention of a high rejection level. After three UF cycles, the water flux recovery of the PAES-NS membrane was as high as 96%.

Biodegradation Studies of Novel Fluorinated Di-Vinyl Urethane Monomers and Interaction of Biological Elements with Their Polymerized Films.

The monomeric components of resin composites in dental restorative materials are susceptible to hydrolysis in the oral cavity. The main objective of this study was to assess the bio-stability of fluorinated urethane dimethacrylates and determine the nature of fluoro-chemistry interactions with protein and bacterial adhesion (both sources of hydrolytic activity) onto cured resin. Degradation studies were performed in the presence of either albumin (in a mildly alkaline pH) or cholesterol esterase (CE). The surface chemistry of the polymers was assessed by water contact angle measurements, pre- and post- incubation with albumin. Adhesion of Streptococcus mutans to cured resin was investigated. The fluorinated monomers were more stable against degradation when compared to the commercial monomer bisphenol A-diglycidyl methacrylate (BisGMA). While fluorinated monomers showed hydrolytic stability with respect to CE, all fluorinated monomers underwent some degree of degradation with albumin. The fluoro-chemistry did not reduce protein and/or bacterial adhesion onto the surface, however post incubation with albumin, the fluorinated surfaces still presented hydrophobic character as determined by the high contact angle values ranging from 79° to 86°. These monomers could potentially be used to increase the hydrophobicity of polymeric composites and provide a means to moderate esterolytic degradation associated with the monomeric component of the polymers within the oral cavity.

Preparation and Study of Shape Memory in Epoxy Resins

Shape memory polymers (SMPs) are stimuli‐response materials known for their ability to be actuated from temporary shape into original shape. Because of this unique functionality SMPs are promising materials for diverse applications fields, including smart biomedical devices, aviation, automobile, structures or coatings. In this article, the work has been focused on the chemical modification of an epoxy monomer Bisphenol A diglycidyl ether (DGEBA) which was carried out by using allyl amines as curing agents and a thiol. When both systems Epoxy‐Amine/Tiol‐Ene were photopolymerized, a soft phase is introduced through a thiol‐ene system and a rigid phase is given by the polymerization of the epoxy polymer when it reacts with the curing agent allyl amine. One of the main requirements in SMPs is the presence of soft and rigid phases. The study of the effect of the concentration of three different curing agents, allyl amine type, over the capacity of the conformed polymers to return to their original shape was evaluated. DMA analysis was used to determine the Tg in the polymers, once obtained, the polymers were treated on a hot water bath above 10 °C their Tg, then the evaluation of the memory shape was carried out by two tests, bending and torsion. SMPs were obtained and specimens with 20% of concentration of allyl amine as curing agent showed an improvement in their ability of memory shape with a 99% of recovery.

Evidence of Absence: Estrogenicity Assessment of a New Food-Contact Coating and the Bisphenol Used in Its Synthesis.

Consumer concerns about exposure to substances found in food contact materials with estrogenic activity (EA) have created substantial demand for alternatives. We assessed the potential EA of both a new bisphenol monomer used to synthesize polymeric coatings for metal food-contact applications and the nonintentionally added substances (NIAS) that may migrate into food. We evaluated tetramethyl bisphenol F (TMBPF) using in vitro and in vivo assays. We extracted the polymeric coating using food simulants ethanol (50% v/v) and acetic acid (3% w/v) and measured migration using tandem liquid chromatography (LC)/mass spectrometry (MS) and LC time-of-flight MS for TMBPF and NIAS, respectively. We also tested migrants for EA using the E-SCREEN assay. TMBPF did not show estrogenic activity in the uterotrophic assay and did not alter puberty in male and female rats or mammary gland development in female rats. Neither TMBPF nor the migrants from the final polymeric coating increased proliferation of estrogen-sensitive MCF7 cells. TMBPF did not show estrogen-agonist or antagonist activity in the estrogen receptor-transactivation assay. TMBPF migration was below the 0.2 parts per billion detection limit. Our findings provide compelling evidence for the absence of EA by TMBPF and the polymeric coating derived from it and that human exposure to TMBPF would be negligible.

Effect of pendant group containing fluorine on the properties of sulfonated poly(arylene ether sulfone)s as proton exchange membrane

Three kinds of sulfonated poly(arylene ether sulfone) (xF-SPAES-40) were synthesized to explore the influence of the hydrophobic moieties on the copolymers as proton exchange membrane. Three bisphenol monomers containing different content of fluorine were reacted with 3,3′-disulfonate-4,4′-dichlorodiphenylsulfone and 4,4′-dichlorodiphenylsulfone to form xF-SPAES-40 polymers, respectively. The chemical structure of xF-SPAES-40 polymers was identified using 1H Nuclear magnetic resonance spectroscopy and Fourier transform infrared spectroscopy. The phase morphology of the obtained membranes was confirmed by small-angle X-ray scattering (SAXS) and atomic force microscopy (AFM). The properties of these sulfonated polymers towards application as a proton exchange membrane were evaluated. The morphological analysis of AFM and SAXS revealed that introduction of fluorine to the pendant group promotes microphase separation. When compared with 0F-SPAES-40, the 1F-SPAES-40 exhibited the best oxidative stability and dimensional stability at 30–90 °C. The 2F-SPAES-40 showed the highest proton conductivity among them. These results indicated that the hydrophobic components of SPAES including optimal content of fluorine were in favor of promoting proton conductivities, oxidative stability, and restraining water swelling.

Drinking water contaminants from epoxy resin-coated pipes: A field study

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.

UV light copolymerization of dimethyl vinylphosphonate with bisphenol A ethoxylate dimethacrylate

Dimethyl vinylphosphonate (DMVP), a very promising monomer, was copolymerized with acrylic monomer bisphenol A ethoxylate dimethacrylate (BEMA), in different molar ratios, by radical photoinitiated polymerization in the presence of photoinitiator Darocur 4265 (3 wt%) and in the absence of solvent. The UV light polymerization was an efficient method to obtain polymers in a green procedure. The molar ratio between DMVP and acrylic monomer BEMA varied between 1:1 and 5:1. The copolymers were characterized by FTIR, thermal analysis, water uptake and conductivity. From the ATR-FTIR spectra of DMVP-BEMA copolymers at the molar ratios of 1:1–5:1, it was observed that the intensity of P-O-C aliphatic band increased with increases in DMVP content. The synthesized copolymers showed good thermal stability in the range of 335–390 °C. DMVP:BEMA copolymer at 1:1 molar ratio displayed the highest stability, with decomposition temperature above 390 °C, the highest temperature in the series. The water uptake decreased with increases in DMVP content and this behavior was correlated with the ionic conductivity. Based on the Bode diagrams, the ionic conductivity of DMVP:BEMA of 1:1 molar ratio was 6.15 × 10−8 S cm−1 and that of DMVP:BEMA of 2:1 molar ratio was 3.69 × 10−8 S cm−1 which were considered promising as valuable conducting materials.