The effects of flame retardant silica (SiO) and magnesium hydroxide (Mg(OH)) on the thermal decomposition process of polyimide (PI) are discussed in this paper. Firstly, the decomposition process of PI in a nitrogen and oxygen atmosphere was studied by thermogravimetric analysis and differential scanning calorimetry methods, and the kinetic parameters were calculated by the nonlinear fitting method. In an inert atmosphere, PI decomposition consists of a three-step endothermic reaction, whereas in an oxygen atmosphere, PI decomposition consists of two steps, in which the first step does not change, and the second step changes to a violent exothermic peak. The effects of 3 wt % SiO (SPI) and 3 wt % Mg(OH) (MPI) on the degradation kinetics of PI are discussed. The results show that under an oxygen atmosphere, SiO and Mg(OH) hydroxide mainly delayed the second-step oxidation exothermic peak temperature of PI by 5 °C. In summary, the first step of the PI degradation is not affected by oxygen, and the flame retardant mainly acts in the second step, which can delay the oxidation heat release. In addition, the addition of SiO could prevent PI from aging whereas Mg(OH) has barely effect on the aging of PI.
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http://dx.doi.org/10.3390/polym14142791 | DOI Listing |
Int J Biol Macromol
January 2025
Engineering Research Center for Hemp and Product in Cold Region of Ministry of Education, School of Light Industry and Textile, Qiqihar University, Qiqihar 161006, PR China. Electronic address:
From the perspective of sustainable development and practical applications, there is a significant demand for the design of advanced cellulose-based film materials with superior mechanical, optical, and functional properties utilizing environmentally friendly strategies. Herein, biodegradable, mechanically robust and flame-retardant cellulose films with adjustable optical performance were successfully fabricated by in situ synthesis of NH-UiO(Zr)-66 via a DMF-free green process at room temperature. The results indicate that the introduction of NH-UiO(Zr)-66 enables films to realize a desirable flame retardancy (the limiting oxygen index (LOI) increased significantly from 19.
View Article and Find Full Text PDFEnviron Res
January 2025
Man-Technology-Environment Research Center (MTM), Örebro University, Örebro SE-701 82, Sweden.
As the volume of plastic waste from electrical and electronic equipment (WEEE) continues to rise, a significant portion is disposed of in the environment, with only a small fraction being recycled. Both disposal and recycling pose unknown health risks that require immediate attention. Existing knowledge of WEEE plastic toxicity is limited and mostly relies on epidemiological data and association studies, with few insights into the underlying toxicity mechanisms.
View Article and Find Full Text PDFEnviron Res
January 2025
Institute of Science and Technology, São Paulo State University (UNESP), Av. Três de Março, 511, Alto da Boa Vista, 18087-180 Sorocaba, SP, Brazil. Electronic address:
This study provides comprehensive overview of the current level, sources and human exposure risk to hazardous polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs), and polychlorinated biphenyls (PCBs) in South American outdoor air. Research documents were obtainable for only 6 countries within the target period (2014 - 2024). For all contaminants, urban concentrations exceeded that of rural/remote locations.
View Article and Find Full Text PDFChem Biol Interact
January 2025
Department of Environment and Planning, Centre for Environmental and Marine Studies, University of Aveiro, 3810-193 Aveiro, Portugal. Electronic address:
Research has consistently linked exposure to particulate matter (PM) with adverse health outcomes, including cardiovascular and pulmonary morbidity and mortality. Understanding the mechanisms by which PM leads to these effects on human health is crucial for developing effective mitigation strategies. One aspect of PM research that has gained increased attention in the past few years is the bioaccessibility of inhaled PM-bound pollutants that have potential to cause adverse health effects.
View Article and Find Full Text PDFJ Hazard Mater
January 2025
Laboratory of Environmental Toxicology, Chulabhorn Research Institute, Bangkok 10210, Thailand; Center of Excellence on Environmental Health and Toxicology (EHT), OPS, Ministry of Higher Education, Science, Research and Innovation, Bangkok, Thailand. Electronic address:
2-Ethylhexyl diphenyl phosphate (EHDPP) is a replacement flame-retardant commonly found in several environmental matrices and human biospecimens. Although some adverse effects of EHDPP have been identified, the endocrine-disrupting effects of EHDPP and its key metabolites on the human estrogen receptor (ER) are largely unknown. Herein, we report for the first time that EHDPP, at concentrations found in the environment and humans, significantly promoted estrogenic activity and synergized with 17β-estradiol-induced ER transactivation.
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