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Materials (Basel, Switzerland) Feb 2021This paper reviews the current trends in replacing commonly used plasticizers in poly(vinyl chloride), PVC, formulations by new compounds with reduced migration, leading... (Review)
Review
This paper reviews the current trends in replacing commonly used plasticizers in poly(vinyl chloride), PVC, formulations by new compounds with reduced migration, leading to the enhancement in mechanical properties and better plasticizing efficiency. Novel plasticizers have been divided into three groups depending on the replacement strategy, i.e., total replacement, partial replacement, and internal plasticizers. Chemical and physical properties of PVC formulations containing a wide range of plasticizers have been compared, allowing observance of the improvements in polymer performance in comparison to PVC plasticized with conventionally applied bis(2-ethylhexyl) phthalate, di-n-octyl phthalate, bis(2-ethylhexyl) terephthalate and di-n-octyl terephthalate. Among a variety of newly developed plasticizers, we have indicated those presenting excellent migration resistance and advantageous mechanical properties, as well as those derived from natural sources. A separate chapter has been dedicated to the description of a synergistic effect of a mixture of two plasticizers, primary and secondary, that benefits in migration suppression when secondary plasticizer is added to PVC blend.
PubMed: 33578880
DOI: 10.3390/ma14040844 -
Cureus Oct 2023This editorial explores the potential link between vinyl chloride (VC) and cardiovascular diseases, specifically in the context of a recent train derailment in East...
This editorial explores the potential link between vinyl chloride (VC) and cardiovascular diseases, specifically in the context of a recent train derailment in East Palestine, Ohio. The primary finding of this article suggests a likely increased risk of cardiovascular factors associated with vinyl chloride exposure. This underscores the importance of proactive risk management and enhanced population monitoring. Together, these findings highlight the need for timely interventions to address cardiovascular health concerns in exposed populations.
PubMed: 37954788
DOI: 10.7759/cureus.46835 -
ACS Omega Jul 2019Over 80 heat treatment experiments have been made on samples of chloride-contaminated plutonium dioxide retrieved from two packages in storage at Sellafield. These...
Over 80 heat treatment experiments have been made on samples of chloride-contaminated plutonium dioxide retrieved from two packages in storage at Sellafield. These packages dated from 1974 and 1980 and were produced in a batch process by conversion of plutonium oxalate in a furnace at around 550 °C. The storage package contained a poly(vinyl chloride) (PVC) bag between the screw top inner and outer metal cans. Degradation of the PVC has led to adsorption of hydrogen chloride together with other atmospheric gases onto the PuO surface. Analysis by caustic leaching and ion chromatography gave chloride contents of ∼2000 to >5000 ppm Cl (i.e., μgCl g of the original sample). Although there are some subtle differences, in general, there is surprisingly good agreement in results from heat treatment experiments for all the samples from both cans. Mass loss on heating (LOH) plateaus at nearly 3 wt % above 700 °C, although samples that were long stored under an air atmosphere or preexposed to 95% relative humidity atmospheres, gave higher LOH up to ∼4 wt %. The majority of the mass loss is due to adsorbed water and other atmospheric gases rather than chloride. Heating volatilizes chloride only above ∼400 °C implying that simple physisorption of HCl is not the main cause of contamination. Interestingly, above 700 °C, >100% of the initial leachable chloride can be volatilized. Surface (leachable) chloride decreases quickly with heat treatment temperatures up to ∼600 °C but only slowly above this temperature. Storage in air atmosphere post-heat treatment apparently leads to a reequilibration as leachable chloride increases. The presence of a "nonleachable" form of chloride was thus inferred and subsequently confirmed in PuO samples (pre- and post-heat treatment) that were fully dissolved and analyzed for the total chloride inventory. Reheating samples in either air or argon at temperatures up to the first heat treatment temperature did not volatilize significant amounts of additional chloride. With regard to a thermal stabilization process, heat treatment in flowing air at 800 °C with cooling and packaging under dry argon appears optimal, particularly, if thinner powder beds can be maintained. From electron microscopy, heat treatment appeared to have the most effect on degrading the square platelet particles compared to those with the trapezoidal morphology.
PubMed: 31460372
DOI: 10.1021/acsomega.9b00719 -
Environmental Science and Ecotechnology Apr 2023
PubMed: 36949895
DOI: 10.1016/j.ese.2023.100259 -
Toxicological Sciences : An Official... May 2023Alterations in physiological processes in pancreas have been associated with various metabolic dysfunctions and can result from environmental exposures, such as...
Alterations in physiological processes in pancreas have been associated with various metabolic dysfunctions and can result from environmental exposures, such as chemicals and diet. It was reported that environmental vinyl chloride (VC) exposure, a common industrial organochlorine and environmental pollutant, significantly exacerbated metabolic-related phenotypes in mice fed concurrently with high-fat diet (HFD) but not low-fat diet (LFD). However, little is known about the role of the pancreas in this interplay, especially at a proteomic level. The present study was undertaken to examine the protein responses to VC exposure in pancreas tissues of C57BL/6J mice fed LFD or HFD, with focus on the investigation of protein expression and/or phosphorylation levels of key protein biomarkers of carbohydrate, lipid, and energy metabolism, oxidative stress and detoxification, insulin secretion and regulation, cell growth, development, and communication, immunological responses and inflammation, and biomarkers of pancreatic diseases and cancers. We found that the protein alterations may indicate diet-mediated susceptibility in mouse pancreas induced by HFD to concurrent exposure of low levels of inhaled VC. These proteome biomarkers may lead to a better understanding of pancreas-mediated adaptive or adverse response and susceptibility to metabolic disease.
Topics: Animals; Mice; Proteome; Vinyl Chloride; Diet, High-Fat; Proteomics; Mice, Inbred C57BL; Pancreas; Biomarkers
PubMed: 36892438
DOI: 10.1093/toxsci/kfad024 -
Biomolecules Mar 2023The bioactive natural substance, hamamelitannin, was effectively synthesized in two ways. The chemical acylation of 2,3--isopropylidene-α,β-D-hamamelofuranose promoted...
The bioactive natural substance, hamamelitannin, was effectively synthesized in two ways. The chemical acylation of 2,3--isopropylidene-α,β-D-hamamelofuranose promoted by BuSnO using 3,4,5-tri--acetylgalloyl chloride, followed by the deprotection provided hamamelitannin in 79%. Pilot enzymatic benzoylation of D-hamamelose using vinyl benzoate (4 equiv.) and Lipozyme TL IM as a biocatalyst in -butyl methyl ether (-BuMeO) gave mainly benzoylated furanoses (89%), of which tribenzoates reached (52%). Enzymatic galloylation of 2,3--isopropylidene-α,β-D-hamamelofuranose with vinyl gallate under the catalysis of Lipozyme TL IM in -butyl alcohol (-BuOH) or -BuMeO provided only the 5--galloylated product. The reaction in -BuMeO proceeded in a shorter reaction time (61 h) and higher yield (82%). The more hydrophobic vinyl 3,4,5-tri--acetylgallate in the same reactions gave large amounts of acetylated products. Vinyl gallate and triacetylgallate in the enzymatic acylation of D-hamamelose with Lipozyme TL IM in -BuMeO yielded 2',5-diacylated hamamelofuranoses in a yield below 20%. The use of other vinyl gallates hydrophobized by methylation or benzylation provided 2',5-diacylated hamamelofuranoses in good yields (65-84%). The reaction with silylated vinyl gallate did not proceed. The best results were obtained with vinyl 2,3,5-tri--benzyl gallate, and the only product, 2',5-diacylated hamamelofuranoside precipitated from the reaction mixture (84% in 96 h). After debenzylation, hamamelitannin was obtained an 82% yield from hamamelose in two steps. This synthesis is preparatively undemanding and opens the way to multigram preparations of bioactive hamamelitannin and its analogues.
Topics: Gallic Acid; Acylation
PubMed: 36979454
DOI: 10.3390/biom13030519 -
Journal of Visualized Experiments : JoVE Jan 2020Vinyl chloride (VC), an abundant environmental contaminant, causes steatohepatitis at high levels, but is considered safe at lower levels. Although several studies have...
Vinyl chloride (VC), an abundant environmental contaminant, causes steatohepatitis at high levels, but is considered safe at lower levels. Although several studies have investigated the role of VC as a direct hepatotoxicant, the concept that VC modifies sensitivity of the liver to other factors, such as nonalcoholic fatty liver disease (NAFLD) caused by high-fat diet (HFD) is novel. This protocol describes an exposure paradigm to evaluate the effects of chronic, low-level exposure to VC. Mice are acclimated to low-fat or high-fat diet one week prior to the beginning of the inhalation exposure and remain on these diets throughout the experiment. Mice are exposed to VC (sub-OSHA level: <1 ppm) or room air in inhalation chambers for 6 hours/day, 5 days/week, for up to 12 weeks. Animals are monitored weekly for body weight gain and food consumption. This model of VC exposure causes no overt liver injury with VC inhalation alone. However, the combination of VC and HFD significantly enhances liver disease. A technical advantage of this co-exposure model is the whole-body exposure, without restraint. Moreover, the conditions more closely resemble a very common human situation of a combined exposure to VC with underlying nonalcoholic fatty liver disease and therefore support the novel hypothesis that VC is an environmental risk factor for the development of liver damage as a complication of obesity (i.e., NAFLD). This work challenges the paradigm that the current exposure limits of VC (occupational and environmental) are safe. The use of this model can shed new light and concern on the risks of VC exposure. This model of toxicant-induced liver injury can be used for other volatile organic compounds and to study other interactions that may impact the liver and other organ systems.
Topics: Administration, Inhalation; Animals; Diet, High-Fat; Environmental Exposure; Humans; Liver; Liver Diseases; Mice, Inbred C57BL; Models, Biological; Obesity; Vinyl Chloride
PubMed: 31984951
DOI: 10.3791/60351 -
International Journal of Environmental... Dec 2021Volatile organic compounds (VOCs) comprise various organic chemicals which are released as gases from different liquids or solids. The nature and impact of the health... (Review)
Review
Volatile organic compounds (VOCs) comprise various organic chemicals which are released as gases from different liquids or solids. The nature and impact of the health effects are dependent on the VOCs concentrations and, also, on the exposure time. VOCs are present in different household, industrial or commercial and products, but their accumulation in air and water has primarily gained attention. Among VOCs, trichloroethylene and vinyl chloride are the most toxic and carcinogenic compounds. In order to improve the indoor air and water quality, VOCs can be removed via efficient approaches involving nanomaterials, by using techniques such as adsorption, catalysis or photocatalysis. In the recent years, the development of manufacturing procedures, characterization techniques and testing processes has resulted in the growth of na-nomaterials obtaining and applications, creating great possibilities and also a tremendous prov-ocation in applying them for highly efficient VOCs removal. This review is intended to contrib-ute to the improvement of awareness and knowledge on the great potential that nanomaterials have in VOCs removal, in order a to improve indoor and outdoor environment, but also the worldwide water sources.
Topics: Air Pollutants; Air Pollution, Indoor; Environmental Monitoring; Environmental Pollutants; Nanostructures; Volatile Organic Compounds; Water Quality
PubMed: 34948756
DOI: 10.3390/ijerph182413147 -
Hepatic Medicine : Evidence and Research 2020Primary liver cancer has the sixth highest incidence and fourth highest cancer mortality worldwide. Hepatitis B is the leading cause of liver cancer, though its... (Review)
Review
Primary liver cancer has the sixth highest incidence and fourth highest cancer mortality worldwide. Hepatitis B is the leading cause of liver cancer, though its incidence is decreasing with vaccination. Alcohol is the leading cause of liver transplant, cirrhosis, and cancer in the developed world, and is projected to surpass hepatitis B as the leading hepatic cancer etiology worldwide. Tobacco smoking has shown a positive association with liver cancer in a majority of studies, though not all. Aflatoxin, a mycotoxin produced by , is estimated to account for 3-20% of global liver cancer cases, 40% of which occur in sub-Saharan Africa. These statistics are confounded by the prevalence of hepatitis B, which may have a synergistic effect on hepatic carcinogenesis. Aflatoxin is ingested and likely inhaled from agricultural products, placing farmers, food processors, and textile workers in developing nations at risk. Vinyl-chloride is used in the production of PVC plastics and causes rare liver angiosarcoma, hepatocellular carcinoma, and other neoplasms. Arsenic and cadmium are naturally-occurring, hepatocarcinogenic metals with high occupational exposure in industries involving coal, metals, plastics, and batteries. Millions of laborers in waste-disposal and manufacturing are exposed to organic solvents and N-nitrosamines, which vary from carcinogenic (group 1) to possibly carcinogenic (group 2B) in their IARC designation. Insecticide DDT is possibly hepatocarcinogenic (group 2B), though continues to be used for malaria control in the developing world. While suggested by case reports, anabolic steroids and oral contraceptives have not been shown to increase liver cancer risk in large studies.
PubMed: 33447099
DOI: 10.2147/HMER.S278070 -
ACS Catalysis Jan 2024We report the organocatalytic synthesis of Si-stereogenic compounds via desymmetrization of a prochiral silanediol with a chiral imidazole-containing catalyst. This...
We report the organocatalytic synthesis of Si-stereogenic compounds via desymmetrization of a prochiral silanediol with a chiral imidazole-containing catalyst. This metal-free silylation method affords high yields with enantioselectivity up to 98:2 for various silanediol and silyl chloride substrate combinations (including secondary alkyl, vinyl, and H groups), accessing products with potential for further elaboration. NMR and X-ray studies reveal insight into the H-bonding interactions between the imidazole organocatalyst and the silanediol and the dual activating role of the Lewis basic imidazole to account for the high enantioselectivity.
PubMed: 38269039
DOI: 10.1021/acscatal.3c03932