Design of Side-Chain Fluorinated Polyethers Featuring Predefined Breaking Points for Fluorosurfactant Applications

3 - Manufacture

Some quenched and annealed samples of tetrafluoroethylene copolymers containing perfluoropropyl vinyl ether, perfluoromethyl vinyl ether, and hexafluoropropene were studied by small-angle X-ray scattering and differential scanning calorimetry. Small-angle X-ray scattering experimental spectra were analyzed by a fitting method with the profiles calculated from some theoretical distribution models of the lamellar thickness. The mathematical evaluation of small-angle X-ray scattering patterns has provided crystallinity values which were compared with those obtained by wide-angle X-ray scattering in order to obtain information on the organization of the lamellar stacks. The experimental results allow one to conclude that, during the annealing of the quenched fluorinated copolymers, at increasing temperatures, the melting of the thin lamellae takes place together with the appearance and the growth of nonlamellar crystallites.

Fluoroalkyl acrylate (FA) polymers are widely used as fluorine-based water and oil repellents for various materials such as textiles, carpets and paper. Water repellency can also be achieved with silicone-based polymers and hydrocarbon polymers, but with FA polymers even higher resistance to water pressure, better oil repellency, and antifouling properties can be attained. For that reason, generally fluorine-based systems are currently employed as water and oil repellents. In recent years, extensive investigations and research have been carried out because of increasing concerns about the accumulation in the environment and the living body of perfluorooctanoic acid (PFOA) derived from fluorotelomers, which constitute the raw material for FA polymers. This chapter gives an overview of the PFOA issue and the production process of FA polymers, touching upon the relationship between the water-repellent performance of FA polymers and their structures. The future prospects of alternative technologies to produce environmentally friendly (short-chain type) fluorine-based water and oil repellents and PFOA-free products are discussed.

Absolute rate coefficients for the reaction between OH radicals and perfluoro propyl vinyl ether (PPVE) were obtained using the technique of pulsed laser photolysis with the detection of OH radicals by laser induced fluorescence. Rate coefficients were measured over a range of temperatures (212-298 K) and at either 50 or 200 Torr bath-gas (N2 or N2/O2). The temperature dependence of the rate coefficient is given by k1(212-298 K) = (4.88 ± 0.49) × 10(-13) exp[(564 ± 10)/T] cm(3) molecule(-1) s(-1) with a value at room temperature of (3.4 ± 0.3) × 10(-12) cm(3) molecule(-1) s(-1). No pressure dependence was observed, indicating that the reaction is at the high pressure limit under atmospheric conditions. The accuracy of the rate coefficient obtained was enhanced by on-line optical absorption measurements of PPVE at 184.95 nm using a value of σ(184.95 nm) = (5.64 ± 0.28) × 10(-18) cm(2) molecule(-1) determined in this work. An atmospheric lifetime of a few days for PPVE was calculated. Extensive quantum chemical calculations as a complement to the experimental work are presented in order to determine its probable tropospheric degradation mechanism.

Six trace metals (Cd, Pb, Cr, Cu, Zn, and Mn) and 2 perfluorinated compounds (PFCs), perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), were analyzed in 43 representative tea products (including 18 green, 12 Oolong, and 13 black teas) from 7 main tea production provinces in China, using the atomic absorption spectrophotometer for trace metals analysis and HPLC-MS/MS for PFOS and PFOA analysis. The average contents of the 3 essential metals Mn, Cu, and Zn ions in the tea samples were 629.74, 17.75, and 37.38 mg/kg, whereas 3 toxic metals Cd, Cr, and Pb were 0.65, 1.02, and 1.92 mg/kg, respectively. The contents of heavy metals in the 3 types of tea were in the order of black tea > Oolong tea > green tea. Both PFOS and PFOA contents were low and PFOA content was higher than PFOS in the tea samples. The highest concentration of PFOA was 0.25 ng/g dry weight found in a Hunan green tea. The Principal component analysis was performed with the trace metals and PFCs to analyze the relationships of these indices. The results showed that black teas had higher trace metals and PFCs than green and Oolong teas, and the teas from Hunan and Zhejiang provinces had higher Pb and Cr than others. This paper reports trace metals, and perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) in wide range of tea products produced in the south China area. This paper also warns the low PFOS and PFOA pollution in tea.

BackgroundPhthalates are compounds that are used in a wide range of consumer products. However, the contribution of dietary intake to phthalate exposure has not been well defined.ObjectiveThe objective of this study was to assess the contribution of different food types to phthalate exposure. Phthalates are chemicals of concern because of the high levels measured in people and the environment, as well as the demonstrated toxicity in animal studies and limited epidemiological studies. Previous research, although limited, has suggested that phthalates contaminate food in various countries.MethodsWe conducted an exploratory analysis of data collected as part of the 2003–2004 National Health and Nutrition Examination Survey (NHANES). Associations between dietary intake (assessed by a 24-hr dietary recall) for a range of food types (meat, poultry, fish, fruit, vegetable, and dairy) and phthalate metabolites measured in urine were analyzed using multiple linear regression modeling.ResultsWe found that metabolites of di-(2-ethylhexyl) phthalate (DEHP) and high-molecular-weight phthalate metabolites were associated with the consumption of poultry. Monoethyl phthalate, the metabolite of diethyl phthalate (DEP), was associated with vegetable consumption, specifically tomato and potato consumption.DiscussionThese results, combined with results from previous studies, suggest that diet is an important route of intake for phthalates. Further research is needed to determine the sources of food contamination with these toxic chemicals and to describe the levels of contamination of U.S. food in a large, representative U.S. sample.

Microelectromechanical systems (MEMS) have played key roles in many important areas, for example transportation, communication, automated manufacturing, environmental monitoring, health care, defense systems, and a wide range of consumer products. MEMS are inherently small, thus offering attractive characteristics such as reduced size, weight, and power dissipation and improved speed and precision compared to their macroscopic counterparts. Integrated circuit (IC) fabrication technology has been the primary enabling technology for MEMS besides a few special etching, bonding and assembly techniques. Microfabrication provides a powerful tool for batch processing and miniaturizing electromechanical devices and systems to a dimensional scale that is not accessible by conventional machining techniques. As IC fabrication technology continues to scale toward deep submicrometer and nanometer feature sizes, a variety of nanoelectromechanical systems (NEMS) can be envisioned in the foreseeable future. Nanoscale mechanical devices and systems integrated with nanoelectronics will open a vast number of new exploratory research areas in science and engineering. NEMS will most likely serve as an enabling technology, merging engineering with the life sciences in ways that are not currently feasible with microscale tools and technologies.

Association between exposure to perfluoroalkyl substances (PFAS) and endometriosis in the ENDEA case-control study

Metal oxide particles in the submicron and nanometer range endow a wide range of consumer products with unique properties. The widespread use of such products raises concerns on potential toxicity of these materials to man and the environment. Besides their size, the photo-catalytic properties of metal oxide particles are of particular concern. By utilizing molecular probes with tailored optical properties, we investigated the photo-catalytic properties of seven TiO2 (anatase), ZnO and CeO2 manufactured particles in environmental media. Controlled experiments confirmed that the particles catalyzed photo-oxidation and photo-production of reactive oxygen species (ROS), while no ROS generation was observed when the ionic form of the materials was used in place of the particles. While affecting their aggregation and sedimentation, the type of media was not found to strongly influence the photo-catalytic behavior of the particles. Within the size range that was investigated, ZnO particles resulted in the highest production of ROS, while anatase particles possessed the highest oxidative ability. Possible explanations of such behavior are suggested.

8 - Structural and mechanical properties of fats and their implications for food quality

Bisphenol A (BPA) is an endocrine disrupting chemical used in a wide range of consumer products including photoactive dyes used in thermal paper. Recent studies have shown that dermal absorption of BPA can occur when handling these papers. Yet, regulatory agencies have largely dismissed thermal paper as a major source of BPA exposure. Exposure estimates provided by agencies such as the European Food Safety Authority (EFSA) are based on assumptions about how humans interact with this material, stating that ‘typical’ exposures for adults involve only one handling per day for short periods of time (<1 minute), with limited exposure surfaces (three fingertips). The objective of this study was to determine how individuals handle thermal paper in one common setting: a cafeteria providing short-order meals. We observed thermal paper handling in a college-aged population (n = 698 subjects) at the University of Massachusetts’ dining facility. We find that in this setting, individuals handle receipts for an average of 11.5 min, that >30% of individuals hold thermal paper with more than three fingertips, and >60% allow the paper to touch their palm. Only 11% of the participants we observed were consistent with the EFSA model for time of contact and dermal surface area. Mathematical modeling based on handling times we measured and previously published transfer coefficients, concentrations of BPA in paper, and absorption factors indicate the most conservative estimated intake from handling thermal paper in this population is 51.1 ng/kg/day, similar to EFSA’s estimates of 59 ng/kg/day from dermal exposures. Less conservative estimates, using published data on concentrations in thermal paper and transfer rates to skin, indicate that exposures are likely significantly higher. Based on our observational data, we propose that the current models for estimating dermal BPA exposures are not consistent with normal human behavior and should be reevaluated.

Hexabromocyclododecane (HBCD) and polybrominated diphenyl ethers (PBDEs) are additive flame retardants used in a wide range of consumer products. Both compounds have been detected in free-living avian species, but toxicological and molecular end points of exposure are limited. An in vitro approach was used to compare concentration-dependent effects of HBCD and the commercial penta-brominated diphenyl ether mixture DE-71 on cytotoxicity and mRNA expression in cultured hepatocytes derived from embryonic chickens. Neither HBCD-alpha, HBCD-technical mixture (TM), nor DE-71 effected hepatocyte viability at the highest concentrations assessed (30-100 microM). Real-time RT-PCR assays were developed to quantify changes in mRNA abundance of genes associated with chicken xenobiotic-sensing orphan nuclear receptor activation, the thyroid hormone (TH) pathway, and lipid regulation. Exposure to >or= 1 microM HBCD-alpha and HBCD-TM resulted in significant upregulation of cytochrome P450 (CYP) 2H1 (fourfold to sevenfold) and CYP3A37 (5- to 30-fold) at 24 and 36 h. In contrast, 30 microM DE-71 caused a twofold increase of CYP2H1 only. UGT1A9 expression was only upregulated by HBCD-alpha to a maximum of fourfold at >or= 1 microM. Transthyretin, thyroid hormone-responsive spot 14-alpha, and liver fatty acid-binding protein were all significantly downregulated (up to sevenfold) for cells exposed to >or= 1 microM HBCD-alpha and HBCD-TM. DE-71 also downregulated these three target genes twofold to fivefold at concentrations >or= 3 microM. Taken together, our results indicate that xenobiotic-metabolizing enzymes and genes associated with the TH pathway and lipid regulation are vulnerable to HBCD and DE-71 administration in cultured avian hepatocytes and might be useful molecular markers of exposure.

Bisphenol A (BPA) is an anthropogenic chemical compound utilized to manufacture a wide range of consumer products, such as polycarbonate, polyvinyl chloride (PVC), food packages, and thermal papers. Because of its extensive worldwide use, BPA is pervasive in the environment, negatively affecting aquatic life. Therefore, we studied the occurrence, persistence, and ecological risk of BPA in surface water receiving raw leachate from a municipal solid waste (MSW) open dump in Kerawalapitiya, Sri Lanka. Our findings corroborate that the BPA average concentrations in the canal network were 0.4–42.6 µg/L during the wet season and 0.2–4.9 µg/L during the dry season. The levels of BPA at 11 locations (out of 16) during both seasons differed significantly from the upstream sample, where there was no impact from the dump site (p &lt; 0.05), indicating the ubiquitous occurrence and persistence of BPA in the canal network. BPA levels in the waterbodies are greater in the wet period than in the dry period because of the continuous ingress of run‐off‐driven leachate to the canal network. Our study infers that pH and salinity correlate positively with BPA, while temperature, DO, and TSS are negatively correlated with BPA. BPA levels in five locations during the wet season and one during the dry season surpassed the tolerable level of BPA stipulated by the Canadian Federal Environmental Quality Guidelines to safeguard aquatic life, which is 3.5 µg/L. The findings of the acute ecological risk assessment articulate that during the wet season, Mozambique tilapia (Oreochromis mossambicus) and orange chromide (Etroplus maculatus) constitute a high acute risk, while they pose a medium acute risk during the dry season. Our study suggests that the relevant authorities must prevent the ingress of runoff rich with BPA onto the canal network to protect aquatic life.

Phthalates, also known as phthalic acid esters, are a group of chemicals extensively used to enhance the flexibility, transparency, durability, and longevity of plastics. Since their introduction in the 1920s, they have become integral components in a wide range of consumer products, including toys, medical devices, packaging materials, cosmetics, and personal care items. Phthalates are synthesized through the esterification of phthalic acid with various alcohols, resulting in different properties based on the length and type of the alkyl chain. They are broadly classified into low molecular weight and high molecular weight phthalates.Despite their widespread use, phthalates pose significant health concerns due to their ability to leach out of products and enter the human body through ingestion, inhalation, and dermal absorption. Once in the body, they are metabolized into more active compounds that can disrupt endocrine function, leading to reproductive and developmental issues, hormonal imbalances, and other adverse health effects. Research has linked exposure to phthalates with conditions such as premature puberty in girls, reduced sperm quality in men, and various developmental disorders in children. Environmental contamination is another major concern. Phthalates can leach into food and water from packaging materials, with levels increasing under certain conditions such as higher temperatures and prolonged storage. This widespread contamination underscores the necessity for stringent monitoring and regulatory measures to minimize human exposure and safeguard public health. In this chapter, we will explore the mechanisms of phthalate exposure, their impact on human health, and the regulatory authorities needed to address these challenges.

The rapid development in nanotechnology and incorporation of engineered nano-particles (ENPs) in a wide range of consumer products releasing the massive quantities of ENPs in different environmental compartments. The released ENPs from nano-enabled products during their life cycle raising environmental health and safety issues. This review addresses the recent state of knowledge regarding the ENPs ecotoxicity to various organisms lying at different trophic levels. Studies show that reactive oxygen species (ROS) mediated oxidative stress is the primary mechanism of nano-toxicity, either through physical damage by direct contact or release of toxic ions after ENPs dissolution process. Moreover, ENPs uptake, transformation and toxicity on physio-morphological, biochemical and molecular levels in primary producers of terrestrial environment (plants) were also reviewed. Additionally, the intrinsic detoxification mechanism in plants in response to ENPs accumulation was also examined. In the end different sustainable approaches such as biogenic synthesis, clay minerals role, biochar application, bioremediation, and legislative measures are proposed for effective handling and treatment of nano-wastes to get the maximum benefits of nanotechnology with minimum negative outcomes.