PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
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2024
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IF 6.9
Zhongqing Shen,Zixian Jia,Kunpeng Yu,Jing Xie,Lijiao Qin,Lin Gao,Baozhong Li,Xuehai Wang,Jianzhong Yin
Depolymerization shows promise as a strategy for converting waste plastic into monomers that can be used for repolymerization. However, catalytic approaches would be more complex and expensive due to catalyst separation, recovery, and recycling. Here, we present a CO 2 -enhanced subcritical methanolysis method without catalyst that can generate monomer from poly(ethylene terephthalate)(PET). The synergistic effect of CO 2 on the subcritical methanolysis process for PET depolymerization was investigated including the CO 2 initial pressure, reaction temperature and reaction time. Under subcritical conditions, the optimal reaction parameters with PET conversion ratio of 100% and DMT yield of 79.1% are as follows: temperature of 220℃, methanol to PET mass ratio of 6:1 and reaction time of 50 min. Moreover, through the analysis of experimental data, it was concluded that the depolymerization reaction follows a first-order kinetics, with the reaction rate being 2–3 times faster than the traditional process. However, the apparent activation energy for both reactions is found to be similar, with values of 135.1 kJ·mol −1 and 146.2 kJ·mol −1 , respectively.
研究领域:
化学工程
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材料科学
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DOI
高影响因子
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
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2025
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IF 3.7
Qi Zeng,Lili Jian,Songbiao Shi,Qiaoqiao Guo,Syed Raziuddin Quadri,Lijuan Long,Xinpeng Tian
Mangrove ecosystems are critical for coastal protection and biodiversity but are increasingly threatened by plastic pollution, particularly polyethylene terephthalate (PET). In this study, a novel marine bacterium, strain SCSIO 80796T, was isolated from PET debris collected from the mangrove in QiAo Island, Zhuhai, China. Using a polyphasic taxonomic approach, including 16S rRNA gene sequencing, genome-based comparisons (average nucleotide identity [ANI] 72.2%, digital DNA-DNA hybridization [dDDH] 19.0%, average amino acid identity [AAI] 70.6%), and phenotypic and chemotaxonomic analyses, the strain was classified as a novel species within the genus Neptunicella. It is proposed as Neptunicella plasticusilytica sp. nov. (type strain SCSIO 80796ᵀ = MCCC 1K08369T = KCTC 92826T). Genomic analysis revealed that strain SCSIO 80796ᵀ encodes a novel PET-degrading enzyme, NmCut, which degrades PET and yields 105–120 µM of degradation products [terephthalic acid (TPA), mono(2-hydroxyethyl) terephthalate (MHET), bis(2-hydroxyethyl) terephthalate (BHET)] within 48 h at 60°C. NmCut exhibits both structural and evolutionary novelty, featuring a unique PET-binding module (PBM) absent in known PETases. PBM is characterized by a long, positively charged α-helix enriched in aromatic residues, forming a distinct substrate-interacting surface with potential as a transferable domain to enhance the efficiency of other plastic-degrading enzymes. This study not only expands the known diversity within Neptunicella but also highlights the potential of marine-derived microbes in addressing plastic pollution through biotechnological applications.
研究领域:
海洋微生物学
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环境生物技术
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微生物分类学
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生物降解
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基因组学
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酶学
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DOI
PubMed
高影响因子
Materials
·
2023
·Vol. 16
·期 6
·2362
·
IF 3.4
Kuntong Song,Yi Li,Ruiqi Zhang,Nan Wang,Junhong Liu,Wenxia Hou,Qing Zhou,Xingmei Lu
Compared with conventional pyrolysis, steam-assisted pyrolysis of polyethylene terephthalate (PET) can effectively eliminate char and upgrade terephthalic acid (TPA). However, during steam-assisted pyrolysis of PET, the degree of cracking still varies greatly, and while some of the product is excessively cracked to gas, the other part is still insufficiently cracked. In addition, these two types of products seriously affect the yield and purity of TPA. To further enhance the TPA, an attempt was made to reduce these impurities simultaneously by synergistic catalysis among the different components of the metal–acid catalyst. Through a series of experiments, Pt@Hzsm-5 was screened as the optimal catalyst. In the catalytic steam-assisted pyrolysis of PET, the optimum reaction temperature decreased to 400 °C, the calculated yield of TPA increased to 98.23 wt%, and the purity increased to 92.2%. The Pt@Hzsm-5 could be recycled three times with no significant decrease in the obtained yield of TPA. The catalytic mechanism of the Pt@Hzsm-5 was investigated through the analysis of the products and isotope tracing experiments. The Pt catalyzed the hydrogen transfer reaction between the water molecules and PET molecules, which inhibited the excessive cracking of TPA by improving the hydrogen transfer efficiency, reduced the generation of gaseous products, and improved the calculated yield of TPA. In contrast, the Hzsm-5 catalyzed the reaction of monovinyl ester cracking to TPA, effectively reducing the impurities in the solid product, increasing the olefin yield, and improving the purity of TPA. This discovery not only clarifies the synergistic catalytic effect of the Pt@Hzsm-5 in the steam-assisted pyrolysis of the PET reaction but also lays the foundation for further screening of other inexpensive metal–acid catalysts. This is of great significance to realize the industrial application of TPA preparation by PET pyrolysis.Keywords:PET;metal–acid catalyst;steam-assisted pyrolysis;TPA
研究领域:
化学工程
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催化材料
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产品关联
DOI
PubMed
高影响因子
Surfaces and Interfaces
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2025
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IF 6.3
Yinchuan Pu,Duoduo Huang,Su Wang,Wei Xu
Developing robust and durable superhydrophilic surfaces on polyethylene terephthalate (PET) films is critical for advancing their applications in self-cleaning and biomedical technologies. In this study, a coating solution containing polyethyleneimine and HDI polyisocyanate was bar-coated onto PET film surfaces and subsequently cross-linked to form a dense R-NH-CO-NH-R' covalent network. After modification, the PET film surfaces demonstrated superhydrophilicity (WCA=0°) accompanied by a significant increase in surface energy to 79.4 mN/m, while achieving excellent 5B-grade adhesion. Furthermore, when exposed to 40-hour immersion in aqueous solutions, the modified surfaces maintained their superhydrophilicity (0° WCA) with essentially unchanged surface energies. The coatings showed near-complete surface coverage along with substantial covalent bonds retention. Such crosslinking construction approach via bar-coating exhibits promising potential for PET films in superhydrophilic applications.
研究领域:
生物医学工程
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材料科学
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表面工程
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产品关联
DOI
高影响因子
DESIGNED MONOMERS AND POLYMERS
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2022
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IF 3.718
Shichang Chen,Xuhai Fu,Zhijun Jing,Hongzheng Chen
PBT and PET are subjected to thermal-oxidative degradation and thermomechanical degradation during the process of melt blending, which affect the polymer structure and properties. The effect of feed properties of PET and the addition of modified nanoparticles on blends are a question worthy of discussion. This work describes the melting and thermal stability, the crystallization behavior and non-isothermal crystallization kinetic, the rheological behaviors and mechanical properties of several PBT/PET blends prepared by twin-screw melt extrusion. Results show that the molecular chain of the polyester blends obtained by stable extrusion are not significantly degraded, there is only one obvious melting peak and crystallization peak on the thermal analysis curves, and the melting point is lower than either of the two polyesters. An appropriate amount of SD can effectively reduce the crystallization rate of the PBT material and extend the crystallization time. The rheological behavior of PBT/PET blends is complicated than PET raw materials and SD, as well as the melt processing temperature and shear rate will all affect the rheological behavior of the blends. For example, at low shear rate, polyester blends with SD exhibit strong shear thinning behavior. In general, the SD content affects the rheological property of blends in a way similar to the law of influence on crystallization behavior. When SD content is 0.3 wt%, a polyester product with higher elongation at break than pure PBT can be obtained. This can provide a useful reference for preparing commercialized polyester blend products with good melt processability and elongation by simple blending.
研究领域:
高分子科学
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材料科学
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化学工程
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DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
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2023
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IF 9.5
Xiangqiong He,Pengbao Shi,Taixia Wu,Bing Yu,Hailin Cong,Youqing Shen
Transmission through the respiratory tract is one of the most important ways for bacteria and viruses to infect the human body; the use of high-performance antibacterial and antiviral protective equipment is the most effective way to prevent the spread of respiratory diseases. However, at present, most personal protective equipment lacks the ability to kill pathogens. In this paper, a kind of polytetrahydropyrimidine–polyethylene terephthalate functional fiber (PET–PTHP fibers) with highly sustained antibacterial and antiviral properties was prepared. The inactivation rate of the fibers against Staphylococcus aureus and Escherichia coli was as high as 99.99%, and the antibacterial time was more than 72 h. The fibers have an obvious destructive effect on lentiviruses and can reduce the infection rate of lentiviruses in BxPC-3 cells from 25.4 to 9.7%. The cytotoxicity test, cell live/dead staining test, and cell proliferation test all confirmed that PET–PTHP fibers have no obvious cytotoxicity and good cytocompatibility. By applying the functional fibers to the inner layer of the masks, a new type of mask with adsorption, filtration, and killing properties against pathogens was prepared. The filtration efficiency of the new masks was 99.3%, and the pressure drop was 104 Pa. The new masks have excellent air permeability and filtration effect, meet the practical application conditions, and are of grade A; therefore, these masks provide medical protection as well as kill pathogens at the same time, further reducing the risk of human infection.
研究领域:
材料科学
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生物医学工程
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微生物学
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2025
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IF 13.2
Songlei Mo,Xiaohui Liu,Yanqin Wang
The upcycling of polyethylene terephthalate (PET) waste into value-added chemicals is of great interest. However, the diversity of currently accessible PET-derived high-value products remains limited, posing a significant challenge to expanding their scope. Herein, we report a three-step catalytic process for converting PET waste into p-xylylenediamine (PXDA)—an essential monomer for producing high-market-value polyamides, polyimides, and nonisocyanate polyurethanes. Specifically, PET is first transformed into terephthalamide (TP) via ammonolysis, and subsequently dehydrated to terephthalonitrile (TPN), the key intermediate for PXDA synthesis. Successful separation of each intermediate ensures efficient hydrogenation of TPN to PXDA, achieving an overall PXDA yield of 54.5 % from PET. Furthermore, the transformation of common real plastic waste and scale-up experiments demonstrate the robustness and substantial industrial potential of this catalytic route. This study establishes a viable and promising strategy for upcycling PET waste into high value-added product PXDA, significantly broadening the scope of PET-derived chemicals and stimulating further exploration of other valuable derivatives.
研究领域:
高分子化学
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环境科学
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催化化学
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绿色化工
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资源循环利用
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2025
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IF 13.2
Taishun Yang,Qingming Fan,Hao He,Chuang Gao,Zixu Yang,Jing Xu
Closed-loop chemical recycling offers a promising solution to the end-of-life challenges of plastic waste. However, efficiently cleaving bonds to generate value-added products and develop chemically recyclable polymers remains a considerable challenge. We have developed a closed-loop upcycling strategy that depolymerizes poly(ethylene terephthalate) (PET) into bis(2-hydroxyethyl) terephthalate (BHET), followed by polycondensation to produce recycled PET (rPET). A series of xMn/Zn (x = 0, 0.5, 1, 2) catalysts, where x represents the molar ratio of Mn and Zn, were synthesized and employed to depolymerize PET plastic into the BHET monomer. The efficient PET glycolysis approach, utilizing the high surface area and weak acid sites of the 1Mn/Zn catalyst, achieved complete depolymerization of PET plastic with a BHET yield of 93.6 %. The recovered monomers can be utilized to remanufacture rPET, which exhibits competitive molecular weight, thermal stability, and rheological properties. The energy efficiency and techno-economic feasibility of the strategy for recycling PET waste plastic were assessed by constructing a lab-scale 5.0 g-grade process and simulating a 1-ton-grade process. This work introduces a closed-loop “PET-BHET-rPET” process, addressing end-of-use challenges, offering a cost-effective method, and providing a sustainable solution for upcycling plastic waste.
研究领域:
材料科学
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环境科学
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化学工程
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产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2024
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IF 12.2
Si-Qi Chen,Qing-Song Huang,Yang Li,Jing Wu,Sheng Chen,Zheng-Fei Yan
Polyethylene terephthalate (PET) is one of the most widely used plastics, but its fragmentation into microplastics poses significant environmental challenges. The recycling of PET microplastics is hindered by their low solubility and widespread dispersion in the environment, making microbial in-situ degradation a promising solution. However, existing PET-degrading strains exhibited the limited effectiveness, primarily due to the diffusion of secreted hydrolases away from the PET surface. In this study, Stenotrophomonas pavanii JWG-G1 was engineered to achieve the targeted aggregation of PET hydrolase PETase on the cell surface by fusing it with an endogenous anchor protein. This approach aims to maximise the local concentration of PETase around PET, thereby increasing the overall rate of PET degradation. The PETase surface-aggregated system, S. pavanii /PaL-PETase, demonstrated the highest degradation efficiency, achieving 63.3 % degradation of low-crystallinity PET (lcPET) and 27.3 % degradation of high-crystallinity PET bottles (hcPET) at 30 °C. This represents the highest degradation rate reported for a displayed whole-cell system at ambient temperature. Furthermore, this system exhibited broad-spectrum degradation activity against various polyesters. These findings suggest that this system offers a promising, eco-friendly solution to PET and other polyester pollution, with potential implications for environmental bioremediation strategies.
研究领域:
环境科学
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微生物学
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生物技术
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产品关联
DOI
PubMed
高影响因子
Contrast Media & Molecular Imaging
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2019
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IF 1.984
Zi Wang,Liang Cai,Tingting Xu,Dan Tang,Lin Liu,Yue Chen
Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by systemic, symmetrical, and erosive synovitis. RA is one of the most common disabling diseases in the clinic. The main clinical intervention strategies are early diagnosis and early treatment. This study aims to predict the diagnostic value of 68Ga-citrate and 18F-FDG PET/CT in RA by comparing and analyzing the value of 68Ga-citrate and 18F-FDG PET/CT for diagnosing type II collagen-induced arthritis (CIA) in rats. Some CIA models were established. Normal rats were selected as the control group, and 23 days and 40 days were selected as the early and late time points of arthritis, respectively. The semiquantitative analysis of CIA rats was carried out with 68Ga-citrate PET/CT and 18F-FDG PET/CT, and the ratio of the maximum standardized uptake (SUVmax) values in the regions of interest (ROIs) of the hind foot ankle joint and thigh muscle was calculated and statistically analyzed. The distribution of CIA rats in vivo at the 68Ga-citrate 90 min time point was studied, and the ankle tissues were evaluated with hematoxylin and eosin (HE) staining. 68Ga-citrate PET/CT is obviously superior to 18F-FDG PET/CT for CIA imaging, and the statistical results show that the difference between the two examination methods is statistically significant (). The uptake of these two radiopharmaceuticals showed the same trend in arthritis rats with different scores. The distribution of 68Ga-citrate at 90 min is consistent with the trend shown by 68Ga-citrate PET/CT. 68Ga-citrate PET/CT can reflect the inflammatory activity of affected joints in CIA rats earlier and more sensitively than 18F-FDG PET/CT, and this imaging advantage continues until the later stage of inflammation. Therefore, 68Ga-citrate PET/CT is worthy of further promotion and application in the clinical diagnosis of RA.
研究领域:
医学影像学
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风湿病学
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DOI
PubMed
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2021
·Vol. 32
·期 9
·3515-3522
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IF 3.665
Yifan Xiao,Jiaxuan Li,Jun Wu,Liang Song,Yuxi Han,Zhongwei Wang,Qing Yu
Glass fiber reinforced polyethylene terephthalate (PET/GF) with enhanced flame retardancy was prepared with few-layer black phosphorus (BPs) for the first time. The performance of red phosphorus (RP) modified PET/GF was also investigated for comparison. Results show that PET/GF with 0.9 wt% BPs (PET/GF@BP-0.9) can eliminate the ignition of cotton by dripping. The addition of 2.7 wt% of BPs can make the PET/GF sample pass UL 94 V-0 classification, while a much higher of 6.3 wt% RP was needed to pass the same classification. Compared with neat PET/GF, the peak heat release rate (PHRR) and total heat release (THR) rate of PET/GF@BP-2.7 decreases ca. 52.5% and 34.8%, respectively. The studies of char residues reveal that BPs could act as a catalyst for char formation and the formed char could roughen the surface of GF and thus restrain the “wick effect.” Thermogravimetric analysis/infrared spectrometry shows that the addition of BPs significantly inhibited the release of gas-phase products. The attractive abilities of BPs as flame retardant provide a novel and effective way of PET/GF modification.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
Polymer-Plastics Technology and Materials
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2020
·
IF 0
Yang Pan,Guangfeng Wu,Huifang Ma,Shujie Zhou,Huixuan Zhang
Herein, graft-modified ethylene-1-octene copolymer (POE-g-GMA) and styrene-butadiene-styrene triblock copolymer (SBS-g-GMA) were found to be excellent reactive compatibilizers for immiscible poly(ethylene terephthalate) (PET)/high-density polyethylene (HDPE) blends via in-situ reaction compatibilization. With increase in compatibilizer amount, uniform phase morphology was observed in all the blends. Thus, exhibiting enhanced mechanical properties, especially, the notched Izod impact strength. In comparison with SBS-g-GMA, compatibilizer POE-g-GMA demonstrated greater impact on the compatibility. The addition of 15% POE-g-GMA produced blends with best mechanical properties. Besides, both POE-g-GMA and SBS-g-GMA enhanced the melt viscosity of PET/HDPE blends.
研究领域:
材料科学
·
聚合物工程
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产品关联
DOI
危险品化学品经营许可证（带存储）