Polyethylene terephthalate (PET) is a thermoplastic material that is widely used in many application fields, such as packaging, construction and household products. Due to the relevant contribution of PET to global yearly solid waste, the recycling of such material has become an important issue. Disposed PET does not maintain the mechanical properties of virgin material, as exposure to water and other substances can cause multiple chain scissions, with subsequent degradation of the viscoelastic properties. For this reason, chain extension is needed to improve the final properties of the recycled product. Chain extension is generally performed through reactive extrusion. As the latter involves structural modification and flow of PET molecules, rheology is a relevant asset for understanding the process and tailoring the mechanical properties of the final products. This paper briefly reviews relevant rheological studies associated with the recycling of polyethylene terephthalate through the reactive extrusion process.
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http://dx.doi.org/10.3390/ma16093358 | DOI Listing |
Environ Res
January 2025
Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources of China, State Key Laboratory Breeding Base of Marine Genetic Resources, Fujian Key Laboratory of Marine Genetic Resources, Xiamen 361005, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519000, China. Electronic address:
Plastic waste that ends up in the deep sea is becoming an increasing concern. However, it remains unclear whether there is any microflora capable of degrading plastic within this vast ecosystem. In this study, we investigated the bacterial communities associated with different types of plastic-polyamide-nylon 4, 6 (PA), polyethylene (PE), polyethylene terephthalate (PET), and polystyrene (PS)-after one year of in situ incubation in the pelagic deep sea of the Western Pacific.
View Article and Find Full Text PDFEnviron Res
January 2025
State Environmental Protection Key Laboratory of Marine Ecosystem Restoration, National Marine Environmental Monitoring Center, Dalian 116023, China; College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China. Electronic address:
Shipboard domestic sewage, encompassing both black water and gray water, has the potential to transport significant quantities of environmentally harmful microplastics, a concern that has garnered increasing global attention. In this study, Fourier infrared (FTIR) detection was used to detect microplastics in marine domestic wastewater. The primary objective was to evaluate the abundance and characteristics of microplastics present in ship domestic sewage, investigate potential sources and influencing factors, and assess the ecological risks associated with ship sewage through analyses of microplastic abundance and hazard indices.
View Article and Find Full Text PDFMaterials (Basel)
December 2024
Faculty of Physics and Astronomy, University of Wroclaw, 9 Maxa Born Square, 50-204 Wroclaw, Poland.
This research explores how varying proportions of virgin polyethylene terephthalate (vPET) and recycled polyethylene terephthalate (rPET) in vPET-rPET blends, combined with preform thermal conditions during the stretch blow molding (SBM) process, influence PET bottles' microscopic characteristics. Key metrics such as viscosity, density, crystallinity, amorphous phase relaxation, and microcavitation were assessed using response surface methodology (RSM). Statistical analysis, including Analysis of variance (ANOVA) and its power, supported the interpretation of results.
View Article and Find Full Text PDFPolymers (Basel)
January 2025
Department of Mechanical Engineering, Doctoral School, Petroleum-Gas University of Ploiesti, 100680 Ploiesti, Romania.
Polymers (Basel)
December 2024
Department of Chemical Engineering, Kwangwoon University, 20, Kwangwoon-ro, Nowon-gu, Seoul 01897, Republic of Korea.
A novel monomer, 9-bis[4-(2-hydroxyethoxy)phenyl]fluorene di(mercaptopropionate), with a highly refractive index, purity, and excellent UV-curable properties, is synthesized through an optimized Fischer esterification process, reacting 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene with 3-mercaptopropionic acid. The structural characterization of this monomer is performed using Fourier-transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, high-performance liquid chromatography, and liquid chromatography-mass spectrometry. The synthesis conditions are optimized using a design-of-experiments approach.
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