JOURNAL OF BIOSCIENCE AND BIOENGINEERING
·
2019
·
IF 2.032
Lin Huang,Di Meng,Qiaopeng Tian,Shaolan Yang,Huaxiang Deng,Zhengbing Guan,Yujie Cai,Xiangru Liao
Recently, residual plasticizer phthalate esters (PAEs) in the different environments pose a serious health threat to humans and mammals. Biodegradation has been considered a promising and eco-friendly way to eliminate PAEs. In this study, a gene ( baces04 ) encoding the novel PAEs hydrolase , carboxylesterase (BaCEs04), was screened from the genome of Bacillus velezensis SYBC H47 via bioinformatics analysis. Then, baces04 was cloned and expressed in Escherichia coli BL21 (DE3). BaCEs04 belonged to the esterase family VI. It contained a conserved domain (Gly 159 -His 160 -Ser 161 -Leu 162 -Gly 163 ) and a typical serine hydrolase catalytic site (Ser 161 -Asp 204 -His 261 ). The characterization of BaCEs04 showed that the activity was optimal at 60°C and pH 7.5. This enzyme also displayed high resistance to metal ions, organic solvents , and detergents. After treatment with BaCEs04 for 5 h, the degradation ratio of four different 1 mM PAEs, including dimethyl phthalate, diethyl phthalate, dipropyl phthalate, and dibutyl phthalate, was 32.4%, 50.5%, 77.9%, and 86.8%, respectively. The degradation products of four PAEs were identified as their corresponding monoalkyl phthalates. This is the first report that family VI esterase displaying PAE-hydrolysis activity. This study also proved that BaCEs04 could be used as an ideal candidate for the application in bioremediation and industry.
研究领域:
环境科学
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微生物学
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生物化学
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生物技术
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DOI
PubMed
高影响因子
COLLOID JOURNAL
·
2025
·
IF 1.1
Zheqing Gong,Lijun Chen
Acrylate polymer latex and vinyl acetate-tert-carbonatepolymer latex have been widely used as waterborne coating polymers for many industrial applications. A large number of open literatures have reported on the preparation and modification of acrylate latex or vinyl acetate-tert-vinyl carbonate latex, which are synthesized with semi-continuous seeded or soap-free emulsion polymerization or other advanced emulsion polymerization technology. However, the fluorine modified BA/MMA/VAc/VeoVa10 quaternary cross-linked polymer latex has not been reported in the open literatures. In this study, butyl acrylate (BA), methyl methacrylate (MMA), vinyl acetate (VAc), tertiary vinyl carbonate (VeoVa10) are the main monomers, and sulfosuccinateethoxyether alkyl monoester disodium salt (X-40) and alkylphenolpolyoxyethylene ether (LB-407) are used as the emulsifiers. Hydroxypropylmethacrylate (HPMA) and hexafluorobutyl methacrylate (HFMA) are used as the modified monomers. Potassium persulfate (KPS) is the initiator. The fluorine modified polymer latex is prepared via the semi-continuous seeded emulsion polymerization. The structure of the latex film is characterized by Fourier transform infrared spectroscopy (FTIR). Latex films are tested by the thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and contact angle (CA). The particle size of the latex is measured with the Zetatrac dynamic light scattering instrument. The conditions for preparing the resultant latex is optimized and obtained as follows: the amount of emulsifier is 7 wt %; the amount of initiator is 0.8 wt %; the amount of HFMA is 5 wt %. The appearance of the resultant latex is translucent and blue and the average particle size of the polymer latex and its distribution are small, which is 57.89 nm and 0.048, respectively. The water contact angle increased to 95.45°. Thermal decomposition temperature of the film of the fluorine modified polymer latex is 17.33°C higher than that of the film of conventional polymer latex.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
WASTE MANAGEMENT
·
2022
·
IF 8.816
Ning Zhang,Xiaojing Cui,Chizhou Wang,Shaodi Wu,Yuhua Zhao,Yongqin Qi,Xianglin Hou,Haibo Jin,Tiansheng Deng
Vinyl ester resins (VER) and its composites are widely used in chemical industry and municipal engineering. However, its dense three-dimensional network structure makes its degradation and recycling a great challenge. Herein, a novel, efficient and green degradation system gamma-valerolactone (GVL)–H 2 O/p-toluene sulfonic (PTSA) was developed to degrade VER and its composites. VER was completely degraded in the GVL-H 2 O/PTSA at 210 °C and 0.6 MPa. By combing SEM-EDS, IR, NMR, GPC and MALDI-TOF-MS analysis, it was clarified that VER swelled well in GVL, allowing the transfer of PTSA and H 2 O through the resin matrix. The ester bonds in VER were cleaved via hydrolysis with H 2 O catalyzed by the sulfonic acid of PTSA, and high value-added polymer products, i.e., copolymer of styrene and methacrylic acid (SMAA) and bisphenol-A diglycidyl ether (DGEBA), were recycled, which accounted for ca. 87.0 wt% of raw VER. DGEBA can be recycled to prepare a new PU material. The GVL-H 2 O/PTSA system was also effective for degrading UPR and VER-containing composites. This work provides a practical strategy for chemical degradation and recovery of thermoset VER resins.
研究领域:
化学工程
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材料科学
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环境科学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·Vol. 141
·期 14
·e55186
·
IF 2.7
Yong Wang,Liang Wen,Jiajian Liu,Chuncheng Li,Tian Yin,Yaonan Xiao,Zhikui Jiang,Shaohua Wu,Zijian Zhang,Bo Zhang
Bio-based copolymers with excellent mechanical properties and biodegradability are highly desired for packaging and agricultural applications. In this work, a series of high molecular weight bio-based poly(ester-carbonate)s are synthesized using glycolic acid (GA), dimethyl carbonate (DMC), and 1,4-butanediol (BDO). The intrinsic viscosity ([ η ]) of these copolymers ranges from 0.70 to 1.11 dL/g. The tensile strength, elastic modulus, and elongation at break of PBCGA10 are 19.69 ± 2.40 MPa, 151.20 ± 37.17 MPa, and 1173 ± 142%, respectively, which are superior to the mechanical properties of PBAT. The degradation weight loss of PBCGA10 and PBCGA20 after 30 days can reach 8% and 40%, respectively, indicating excellent degradation performance of the copolymers. Moreover, copolymers undergo degradation through a surface degradation mechanism. The main products of copolymer degradation are BDO, CO 2 , and H 2 O, which do not cause harm to organisms and the environment.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2013
·
IF 2.596
Quancai Li,Chunxia Li,Cheng Yang,Chenchang Liu,Guangli Yu,Huashi Guan
Three derivatives of polymannuronic acid (PM) were prepared by chemically polyanionic modification. PM was substituted with phosphate ( OPO 3 2− ), H-phosphonate ( OPO 2 H − ) and sulfate ( OSO 3 − ) groups with the degree of substitution (DS) of 0.41, 1.42 and 1.04, respectively. The structures of all PM derivatives were characterized by FT-IR, 31 P NMR and 13 C NMR spectroscopy . The weight average molecular weight (Mw) was determined by high performance gel permeation chromatography (HPGPC). The antioxidant activities of PM and its derivatives were evaluated in vitro. The results indicated that both phosphate and H-phosphonate groups improved the hydroxyl radical scavenging activity, while sulfate group enhanced the superoxide radical scavenging activity. However, all of the derivatives scavenged DPPH less effectively than PM. The mechanism for how the different anionic substituent groups influenced the antioxidant activities was discussed.
研究领域:
生物化学
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食品科学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 137
·期 2
·48278
·
IF 2.188
Rui-Qi Li,Tao Huang,Shu-Ling Gong
Waterborne saturated polyester (WSP) with high hydroxyl content was prepared through solution polymerization by using stepwise feeding and stage heating methods. The stability of polyester dispersion was enhanced in terms of molecular structure and polymerization process. The conditions of polymerization process, monomer types, and catalyst type were determined. The effects of the ratio of alcohol-to-acid, trimethylolpropane (TMP) content and the feeding method, the content of terminal monomer and branched monomer on the dispersion were investigated. The stability of the self-emulsifying polyester and the water resistance of the film were proved to be excellent. Through transesterification, waterborne unsaturated polyester (WUP) was synthesized by WSP. Polyester-acrylate composite emulsion can be obtained by physical blending or chemical copolymerization of synthetic waterborne polyester. The viscosity of the composite emulsion was improved, and the hardness and water resistance were improved. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48278.
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
Membranes
·
2022
·Vol. 12
·期 12
·1269
·
IF 4.562
Zhengquan Yang,Mingyu Peng,Yu Li,Xiaowei Wu,Tian Gui,Yuqin Li,Fei Zhang,Xiangshu Chen,Hidetoshi Kita
In this work, a dense and acid-resistant beta zeolite membrane was applied to improve the esterification of citric acid and n-butanol, for the first time. Through the continuous removal of the by-product water via pervaporation (PV), the conversion of citric acid was significantly enhanced from 71.7% to 99.2% using p-Toluenesulfonic acid (PTSA) as catalyst. PTSA was a well-known strong acid, and the membrane kept almost no change after PV-esterification, indicating the superior acid resistance of beta zeolite membrane. Compared to the use of acid-resistant MOR zeolite membrane by PV-esterification, a consistently higher conversion of citric acid was obtained using a high-flux beta zeolite membrane. The results showed that high water permeation on the beta zeolite membrane, with good acid resistance, had a strong promoting effect on esterification, leading to an improved conversion. In addition, the citric acid conversion of 97.7% could still be achieved by PV-esterification at a low reaction temperature of 388 K.Keywords:improved esterification;Tributyl citrate;beta zeolite membrane;PV-esterification;high conversion
研究领域:
化学工程
·
材料科学
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产品关联
DOI
PubMed
高影响因子
Forensic Toxicology
·
2024
·
IF 2.8
Zhang Xiaolong,Chen Yuxuan,Liu Jinlei,Wang Mengchao,Dai Yinyin,Zhao Kundi,Gu Jie,Zhang Huimin,Wurita Amin,Hasegawa Koutaro
Purpose Distribution and abuse of imidazole-derived γ-aminobutyric acid (GABA) agonists, such as etomidate and metomidate, and their analogs have been encountered frequently especially in China. The aim of this study was to identify etomidate, metomidate, propoxate, and isopropoxate more accurately by establishing a gas chromatography–mass spectrometry (GC–MS) and liquid chromatography tandem mass spectrometry (LC–MS/MS) method and applying it to real forensic cases. Methods One mg of the seized powder was dissolved in 1 mL of methanol, and subjected to GC–MS and LC–MS/MS. Hair samples were washed and cut into approximately 2 mm sections, then ground to powder by a low-temperature grinder. Twenty mg of the hair powder was extracted with 1 mL of methanol, and the supernatant was subjected to LC–MS/MS. Results Etomidate, metomidate, propoxate, and isopropoxate were chromatographically separated and each mass spectrum was obtained by GC–MS. For LC–MS/MS, tested validation data were all satisfactory. The seized powder samples contained isopropoxate, with an approximate content of 30.9%. Etomidate, etomidate acid, metomidate, and isopropoxate could be determined in the submitted hairs, ranging from 2.89 to 8.09 ng/mg, 0.0591–0.177 ng/mg, 0.342–2.77 ng/mg, and 33.2–130 ng/mg, respectively. Conclusions Mass spectra and ion chromatograms of etomidate, metomidate, isopropoxate, and propoxate were obtained by GC–MS. We have also established a simultaneous and reliable analytical method for etomidate, etomidate acid, metomidate, and isopropoxate in human hair by LC–MS/MS. This is the first report to present analytical results of a novel imidazole-derived GABA agonist isopropoxate in drug abuse cases.
研究领域:
法医学
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药物滥用检测
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分析化学
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产品关联
DOI
PubMed
高影响因子
Journal of Coatings Technology and Research
·
2015
·Vol. 12
·期 3
·525-532
·
IF 1.298
Yi Jie,Ren Runtao,Huang Congshu,Zhang Chuyi,Ma Yupu
Poly(ether ester) polyols consisting of polypropylene glycol-2000 (PPG-2000) and different ratios of ε-caprolactone and lactic acid (LA) had been prepared by polycondensation reactions. Degradable polyurethane (PU) films were prepared with poly (ether ester) polyols and hexamethylene diisocyanate trimer. Hydrolytic degradation experiments demonstrated that PU films could be degradable in artificial seawater. Importantly, the hydrolytic degradation of PU films in artificial seawater increased with the increase of LA content. The results also showed that the surfaces of PU films were renewed and kept active, as revealed by the scanning electron microscope micrographs of degradation PU coatings. Moreover, the copper ion release rates of PU coatings prepared with poly(ether ester) polyols reached steady state at about 35 days. The degradable polyurethanes based on poly(ether ester) polyols (PPG-2000, ε-caprolactone, and LA) could be effective and durable resins for marine antifouling.
研究领域:
材料科学
·
海洋生物学
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DOI
高影响因子
Polymer Chemistry
·
2014
·Vol. 5
·期 8
·3098-3106
·
IF 5.368
Yu Jin,Yufeng Ji,Xiaojiang He,Suli Kan,Haidong Xia,Binqi Liang,Jia Chen,Hao Wu,Kai Guo,Zhenjiang Li
o-Benzenedisulfonimide (OBS) was demonstrated for the first time to be a safe, recyclable, and water-tolerant Brønsted acidic catalyst for the ring-opening polymerization (ROP) of δ-valerolactone and ε-caprolactone using benzyl alcohol as the initiator. The polymerizations proceeded to afford poly(δ-valerolactone) and poly(ε-caprolactone) with controlled molecular weights and narrow polydispersities. The kinetics and chain extension experiments were carried out to confirm the controlled/living fashion of the polymerizations. In addition, 1H NMR and MALDI-TOF MS measurements strongly indicated that the initiator residue was incorporated into the obtained polymers. Furthermore, well-defined poly(δ-valerolactone)-block-poly(ε-caprolactone) has been successfully synthesized via OBS-catalyzed ROP.
研究领域:
高分子化学
·
材料科学
✓ 已验证
DOI
高影响因子
POLYMER ENGINEERING AND SCIENCE
·
2023
·Vol. 63
·期 9
·3025-3036
·
IF 3.2
Xiang-nan Liu,Yuan-meng Wang,Xiang-yuan Li,Jun-ying Zhang,Jing-bo Zhao
A new synthesis route different from convenient epoxy/CO 2 method was established to synthesize a five-membered dicyclocarbonate of bisphenol A (BisA-5dCC), and its hybrid non-isocyanate polyurethanes with epoxy resins (HNIPUs) were reported. Bisphenol A was first reacted with 3-chloro-1,2-propanediol to prepare a bisphenol A tetraol (BisA-4OH), and then was reacted with excess diethyl carbonate to obtain BisA-5dCC. Three polyhydroxyurethanes with H 2 N-terminal groups (PHUs) were synthesized from the aminolysis polyaddition of BisA-5dCC and excess hexanediamine. The PHUs were crosslinked with 1,4-butanediol diglycidyl ether and bisphenol A diglycidyl ether, respectively, and different HNIPUs were prepared. The structures of BisA-4OH, BisA-5dCC, and PHUs were confirmed, and the HNIPUs were characterized by Fourier transform infrared, differential scanning calorimetry, dynamic mechanical analysis, thermogravimetric analysis, and tensile tests. HNIPUs prepared from aromatic epoxy showed higher T g (up to 81°C) and better tensile strength (as high as 60 MPa) than those from aliphatic epoxy. High-performance HNIPUs with excellent thermal and mechanical properties were successfully synthesized. Highlights Dicyclocarbonate of bisphenol A (BisA-5dCC) was prepared from a BisA tetraol. H 2 N-terminated PHUs were synthesized further from the aminolysis of BisA-5dCC. Hybrid non-isocyanate polyurethanes (HNIPUs) were obtained from PHUs and epoxys. HNIPUs prepared from aromatic epoxy showed high T g up to 81°C. They showed excellent tensile strength as high as 60 MPa.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2021
·
IF 3.178
Xiong Zheng,Yanqiong Bao,Dan Qu,Yu Liu,Guangzhao Qin
Fatty acid methyl esters (FAMEs) are the main component of biodiesels. Before the industrial application of FAMEs, it is essential to investigate the thermophysical properties of FAMEs. Thermal conductivity of fuels is used in various processes, such as the design of the heat transfer system and the determination of the temperature distribution of engines. Thus, it is of great significance to acquire accurate experimental data and develop reliable models for obtaining accurate thermal conductivity data of FAMEs. In this work, thermal conductivities of two short-chain FAMEs, methyl butyrate (MeC4:0) and methyl caproate (MeC6:0) were studied experimentally and theoretically. The thermal conductivities of these two FAMEs were measured by the transient hot-wire method at T = 303 to 523 K and p = 0.1 MPa to 15 MPa, the data were correlated as a polynomial function of temperature and pressure, the AADs are 0.38% for MeC4:0 and 0.42% for MeC6:0, respectively. Moreover, the experimental thermal conductivities agree well with the available data from literature. In addition, three classical models (Latini model, Sastri model, Liu model) were used to represent the present experimental data and the results show that Liu model with re-fitted parameters performs better in the prediction of the thermal conductivity of FAMEs, with regard to accuracy.
研究领域:
能源科学
·
物理化学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）