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Chemical Science Apr 2024Poly(vinyl chloride) (PVC) is one of the highest production volume polymers due to its many applications, and it is one of the least recycled due to its chemical... (Review)
Review
Poly(vinyl chloride) (PVC) is one of the highest production volume polymers due to its many applications, and it is one of the least recycled due to its chemical structure and frequent formulation with additives. Developing efficient PVC recycling techniques would enable PVC waste to be reused or repurposed in other processes. Within this context, the literature on PVC modification offers considerable insight into versatile reaction pathways, potentially inspiring new approaches for repurposing PVC waste into value-added products. This perspective provides an overview of PVC functionalization through a lens of chemical recycling, discussing various PVC reactivity trends and their applications with a critical assessment and future outlook of their recycling implications.
PubMed: 38665509
DOI: 10.1039/d3sc06758k -
Environmental Health Perspectives Jul 2000Vinyl chloride (VC) is both a known carcinogen and a regulated chemical, and its production capacity has almost doubled over the last 20 years, currently 27 million... (Review)
Review
Vinyl chloride (VC) is both a known carcinogen and a regulated chemical, and its production capacity has almost doubled over the last 20 years, currently 27 million tons/year worldwide. According to recent reports it is still a cause for concern. VC has been found as a degradation product of chloroethylene solvents (perchloroethylene and trichloroethylene) and in landfill gas and groundwater at concentrations up to 200 mg/m(3) and 10 mg/L, respectively. Worldwide occupational exposure to VC still seems to be high in some countries (e.g., averages of approximately 1,300 mg/m(3) until 1987 in one factory), and exposure may also be high in others where VC is not regulated. By combining the most relevant epidemiologic studies from several countries, we observed a 5-fold excess of liver cancer, primarily because of a 45-fold excess risk from angiosarcoma of the liver (ASL). The number of ASL cases reported up to the end of 1998 was 197 worldwide. The average latency for ASL is 22 years. Some studies show a small excess risk for hepatocellular carcinoma, and others suggest a possible risk of brain tumors among highly exposed workers. Lung cancer, lymphomas, or leukemia do not seem to be related to VC exposure according to recent results. The mutation spectra observed in rat and human liver tumors (ASL and/or hepatocellular carcinoma) that are associated with exposure to VC are clearly distinct from those observed in sporadic liver tumors or hepatic tumors that are associated with other exposures. In rats, the substitution mutations found at A:T base pairs in the ras and p53 genes are consistent with the promutagenic properties of the DNA adduct 1,N(6)-ethenoadenine formed from VC metabolites. Risk assessments derived from animal studies seem to overestimate the actual risk of cancer when comparing estimated and reported cases of ASL.
Topics: Animals; Carcinogens; Carcinoma, Hepatocellular; Environmental Exposure; Epidemiologic Studies; Hemangiosarcoma; Humans; Liver Neoplasms; Occupational Exposure; Rats; Risk Assessment; Vinyl Chloride
PubMed: 10905993
DOI: 10.1289/ehp.00108579 -
Polymers Oct 2019In this study, we investigated the influence of methacryl-functionalized polyhedral oligomeric silsesquioxane (MA-POSS) nanoparticles as a plasticizer and thermal...
In this study, we investigated the influence of methacryl-functionalized polyhedral oligomeric silsesquioxane (MA-POSS) nanoparticles as a plasticizer and thermal stabilizer for a poly(vinyl chloride) (PVC) homopolymer and for a poly(vinyl chloride)/dissononyl cyclohexane-1,2-dicarboxylate (PVC/DINCH) binary blend system. The PVC and the PVC/DINCH blend both became flexible, with decreases in their glass transition temperatures and increases in their thermal decomposition temperatures, upon an increase in MA-POSS content, the result of hydrogen bonding between the C=O groups of MA-POSS and the H-CCl units of the PVC, as determined using infrared spectroscopy. Furthermore, the first thermal decomposition temperature of the pure PVC, due to the emission of HCl, increased from 290 to 306 °C, that is, the MA-POSS nanoparticles had a retarding effect on the decomposition of the PVC matrix. In tensile tests, all the PVC/DINCH/MA-POSS ternary blends were transparent and displayed flexibility, but their modulus and tensile strength both decreased, while their elongation properties increased, upon an increase in MA-POSS concentration, both before and after thermal annealing. In contrast, the elongation decreased, but the modulus and tensile strength increased, after thermal annealing at 100 °C for 7 days.
PubMed: 31635274
DOI: 10.3390/polym11101711 -
American Journal of Disaster Medicine 2015In 2012 in New Jersey, a train derailment resulted in the puncture of a tanker car carrying liquid vinyl chloride under pressure, and a resulting airborne vinyl chloride...
OBJECTIVE
In 2012 in New Jersey, a train derailment resulted in the puncture of a tanker car carrying liquid vinyl chloride under pressure, and a resulting airborne vinyl chloride plume drifted onto the grounds of a nearby refinery. This report details the investigation of exposures and symptoms among refinery workers.
DESIGN AND SETTING
The investigation team met with refinery workers to discuss their experience after the derailment and provided workers a self-administered survey to document symptoms and worker responses during the incident. Associations among categorical variables and experiencing symptoms were evaluated using Fisher's exact test.
PARTICIPANTS
Twenty-six of 155 (17 percent) workers present at the refinery or driving on the access road the date the spill occurred completed the survey.
MAIN OUTCOME MEASURE(S)
Any self-reported symptom following exposure from the vinyl chloride release.
RESULTS
Fifteen workers (58 percent) reported ≥1 symptom, most commonly headache (12, 46 percent). Three (12 percent) reported using respiratory protection. No differences in reporting symptoms were observed by location during the incident or by the building in which workers sheltered. Workers who moved from one shelter to another during the incident (ie, broke shelter) were more likely to report symptoms (Fisher's exact test, p=0.03); however, there are only limited data regarding vinyl chloride concentrations in shelters versus outside.
CONCLUSIONS
Breaking shelter might result in greater exposures, and managers and health and safety officers of vulnerable facilities with limited physical access should consider developing robust shelter-in-place plans and alternate emergency egress plans. Workers should consider using respiratory protection if exiting a shelter is necessary during a chemical incident.
Topics: Accidents, Occupational; Chemical Hazard Release; Cross-Sectional Studies; Female; Humans; Male; New Jersey; Occupational Diseases; Occupational Exposure; Railroads; Vinyl Chloride
PubMed: 26312496
DOI: 10.5055/ajdm.2015.0198 -
Environmental Science and Ecotechnology Apr 2023
PubMed: 36949895
DOI: 10.1016/j.ese.2023.100259 -
Scientific Reports Mar 2022To inhibit the agglomeration of nanotitanium dioxide, a poly (vinyl chloride) (PVC) composite film doped with folic acid-modified titanium dioxide was synthesized and...
To inhibit the agglomeration of nanotitanium dioxide, a poly (vinyl chloride) (PVC) composite film doped with folic acid-modified titanium dioxide was synthesized and characterized using X-ray powder diffraction, X-ray photoelectron spectroscopy and thermogravimetric analysis coupled with Fourier transform infrared spectroscopy. The average grain size of the folic acid-modified titanium dioxide was found to decrease by 1.3 nm, indicating that the cohesiveness of the nanoparticles is decreased. The lowest temperature for 1.0% thermal decomposition of PVC was determined to be 230.0 °C. The decomposition rate at the peak temperature is found to be 39.6% lower than that of a control sample. The stability of the PVC is improved due to a lower number of surface chlorine atoms as well intermolecular attraction. A mechanism for folic acid modification of titanium dioxide-doped PVC is proposed. After doping, the ester groups in the plasticizer show a significant decrease in the vibration peak intensities observed at 1264 cm, 1736 cm and 1106 cm. The doped PVC film suppresses the release of CO, and the strongest vibration peak at 1264 cm is found to be 17.2% lower than that for the blank sample, indicating that doping is beneficial for plasticizer recovery.
Topics: Folic Acid; Plasticizers; Polyvinyl Chloride; Titanium; Vinyl Chloride
PubMed: 35233000
DOI: 10.1038/s41598-022-07177-5 -
Polymers Mar 2021This study examined, the effect of chemically extracted raspberry pomace on the thermal stability, mechanical properties, flammability, chemical structure and processing...
This study examined, the effect of chemically extracted raspberry pomace on the thermal stability, mechanical properties, flammability, chemical structure and processing of poly(vinyl chloride). It was observed that the pomace in this study was used to extract naphtha, thereby permitting the removal of bio-oil as a factor preventing the obtaining of homogeneous composites. Furthermore, adding 20% raspberry pomace filler after extraction extended the thermal stability time for the composites by about 30%. It was observed that composite density, impact strength, and tensile strength values decreased significantly with increasing concentrations of filler in the PVC matrix. At the same time, their modulus of elasticity and Shore hardness increased. All tested composites were characterized by a good burning resistance with a flammability rating of V0 according to the UL94 test. Adding 20 to 40% of a natural filler to the PVC matrix made it possible to obtain composites for the production of flame resistant elements that emitted less hydrogen chloride under fire conditions while ensuring good rigidity.
PubMed: 33805463
DOI: 10.3390/polym13071079 -
Polymers Jan 2023Primer is widely used to prepare bonding of chlorinated poly(vinyl chloride) (CPVC) pipe. The study examined the influences of primer and its major component, acetone,...
Primer is widely used to prepare bonding of chlorinated poly(vinyl chloride) (CPVC) pipe. The study examined the influences of primer and its major component, acetone, on CPVC's mechanical properties. Two types of CPVC product, sheet and pipe, were used in the mechanical testing. Sheet specimens were immersed in acetone or primer for 40 and 10 min, respectively, i.e., the maximum allowable time without mass loss, and then dried in air before the mechanical testing. Pipe (ring) specimens were treated either through immersion in acetone or primer for 30 min or in contact with these solvents locally on the inner surface for 2.5 h, and then air dried for 10.5 days before the mechanical testing. Results showed that CPVC's strength decreased after the absorption of these solvents, and air dry could remove acetone but not completely primer. The study also showed that pipe specimens by local contact with primer could generate brittle fracture. In view that sheet specimens always fractured in a ductile manner, brittle fracture of the pipe specimens could not be caused by CPVC degradation. Rather, strength decrease in the local region could provide a plausible explanation for the brittle fracture behavior, though further investigation is needed.
PubMed: 36771790
DOI: 10.3390/polym15030489 -
American Journal of Public Health Feb 2022In the late 20th century, fetal protection policies barred women from hundreds of thousands of industrial jobs on the pretext that if women became pregnant, their...
In the late 20th century, fetal protection policies barred women from hundreds of thousands of industrial jobs on the pretext that if women became pregnant, their fetuses might be harmed by workplace exposure to toxic chemicals. Beginning in the 1970s, these policies set off a decades-long contest between the chemical industry, government agencies, and the judicial system over how to balance the uncertain reproductive health risks against sex discrimination. This article revives the subject of reproductive health and workplace protections through a historical case study of fetal protection policies at Firestone Plastics, a leader in the postwar vinyl chloride industry. I use formerly secret industry documents to argue that Firestone used scientific uncertainty and gender essentialism to skirt new regulatory pressures and minimize corporate liability. Ultimately, fetal protection policies stymied innovative regulatory efforts to protect all workers-not just women-from reproductive hazards in the workplace. (. 2022;112(2):271-276. https://doi.org/10.2105/AJPH.2021.306539).
Topics: Female; Government Regulation; Hazardous Substances; Health Policy; Humans; Industry; Occupational Exposure; Occupational Health; Pregnancy; Pregnant Women; Vinyl Chloride; Women's Rights
PubMed: 35080929
DOI: 10.2105/AJPH.2021.306539 -
The Western Journal of Medicine Dec 1982The liver plays a central role in toxicology. It is the primary organ of detoxification and elimination by metabolism of many chemicals. Many workplace chemicals can... (Review)
Review
The liver plays a central role in toxicology. It is the primary organ of detoxification and elimination by metabolism of many chemicals. Many workplace chemicals can affect the liver in animals; fewer have been proved to do so in humans. The diverse hepatic effects observed in humans from occupational exposure to chemicals range from fatty infiltration, acute hepatitis and cholestasis to cirrhosis and angiosarcoma. Three important workplace chemicals, prototypes for the toxicities of many others, are carbon tetrachloride, vinyl chloride and the polychlorinated biphenyls (PCB's). These three are described in some detail to highlight principles of occupational toxicology. Most of the hepatic effects produced by chemicals in the workplace have clinical, laboratory and morphological features common to many other forms of liver disease. Therefore, only an astute physician who takes an occupational history will recognize the association between a patient's workplace and liver disease.
Topics: Carbon Tetrachloride Poisoning; Chemical and Drug Induced Liver Injury; Humans; Liver; Occupational Diseases; Polychlorinated Biphenyls; Vinyl Chloride
PubMed: 6819718
DOI: No ID Found