FLUID PHASE EQUILIBRIA
·
2018
·
IF 2.197
Xiangyang Liu,Chenyang Zhu,Feng Yang,Chao Su,Maogang He
An experimental study on the isobaric molar heat capacities of ethyl nonanoate and ethyl dodecanoate was performed at temperatures between 303 K and 393 K and at pressures between 0.1 MPa and 25.2 MPa. An increase of isobaric molar heat capacity with temperature increase was observed, and temperature was found to have a greater effect on isobaric molar heat capacity than pressure. Then the isobaric molar heat capacity data of 18 saturated fatty acid methyl and ethyl esters in literature were selected, to get a general correlation for the isobaric molar heat capacity of saturated fatty acid alkyl esters. The average absolute relative deviation and the maximum deviation of the present correlation from experimental data are lower than 0.70% and 3.82%, respectively. At last, to test the predictive ability of the proposed correlation, the heat capacities of ethyl nonanoate and ethyl dodecanoate were calculated. The average absolute relative deviation and the maximum deviation from our experimental results are 0.88% and 2.10%, respectively.
研究领域:
物理化学
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
DYES AND PIGMENTS
·
2016
·
IF 4.055
Gaofeng Feng,Hong-Fei Qian,Gang Bai,Yan-Chun Liu,Ling-Ling Hu
A series of new kinds of diester/diurethane tethered azo disperse dyes were synthesized through the reaction between the hydroxyl group in disperse dyes, such as C. I. Disperse Red 1 ( 1a ), C. I. Disperse Red 13 ( 1b ), and C. I. Disperse Blue 106 ( 1c ), and terephthaloyl chloride or p -phenylene diisocyanate . Structures of these new dyes were fully characterized with NMR, MS, and FT-IR. Visible absorption measurement in DMF indicated that all new diester/diurethane tethered dyes exhibited a little shorter maximum absorption wavelength and much higher molar extinction coefficient than their prototypes. Moreover, the fastnesses to wash and sublimation of dyeing on polyurethane fibre were dramatically improved due to the dye's moderately increased molecular size. It is an attractive new strategy to synthesize a library of tethered dyes with improved fastness properties using various different tethering agents or disperse dyes.
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
AICHE JOURNAL
·
2018
·Vol. 65
·期 2
·675-683
·
IF 3.326
Hao Qin,Zhen Song,Qian Zeng,Hongye Cheng,Lifang Chen,Zhiwen Qi
The traditional production of long-chain organic esters like isobutyl isobutyrate (BIBE) suffers from severe problems due to the homogenous catalyst in process and complex system thermodynamics. In this work, an innovative bifunctional deep eutectic solvent (DES) is introduced, playing as both reaction catalyst and extraction solvent, to intensify the esterification process. The DES was formed by imidazole (Im) and p -toluenesulfonic acid (PTSA), which was for the first time found acid–base tunable, represented by weak basic DES [3Im:PTSA] and strong acidic DES [Im:2PTSA]. The formation mechanisms of [3Im:PTSA] and [Im:2PTSA] were illustrated by Fourier-transform infrared spectroscopy (FTIR) and COnductor-like Screening MOdel for Real Solvent (COSMO-RS) combined with the Im-PTSA phase diagram. The dual functions of the acidic [Im:2PTSA] in reactive extraction were evaluated by σ -potential analysis and esterification experiments. The high conversion, easy product separation, and good solvent reusability confirm the excellent catalytic and solvent effect of [Im:2PTSA]. © 2018 American Institute of Chemical Engineers AIChE J , 65: 675–683, 2019
研究领域:
化学工程
·
有机合成
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2022
·Vol. 41
·期 4
·476-482
·
IF 3.815
Zhang Jian,Zhu Jie,Hua Zan,Liu Guang-Ming
Soil environment on earth contains a variety of ions, which are expected to play a vital role in the biodegradation of plastics discarded in the environment. In this work, poly(butyleneadipate- co -terephthalate) (PBAT) is employed as a model biodegradable plastic to study the specific ion effects on the enzymatic degradation of polyester plastics. The results show that the specific ion effects on the enzymatic degradation rate of the PBAT films and on the catalytic rate constant for the enzymatic hydrolysis of the ester bonds are strongly dependent on temperature and ionic strength. Both the enzymatic degradation rate and catalytic rate constant decrease following the trends Na + > K + > Ca 2+ and Cl − > SO 4
2− > NO 3
− for cations and anions, respectively, indicating that the ion-specific enzymatic degradation of the PBAT films is closely correlated with the specific ion effects on enzymatic hydrolysis of the ester bonds. Our study shows that the specific ion effects on the enzyme activity can be understood by taking into account the ion-specific cation-anion interaction, ionic dispersion force, salting-out effect and salting-in effect. This study of specific ion effects on the enzymatic hydrolysis of the ester bonds and the resultant enzymatic degradation of the PBAT films would offer us a new clue to develop new biodegradable, environmentally friendly synthetic plastics.
研究领域:
环境科学
·
生物化学
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2024
·
IF 12.2
Zhitong Jiang,Xue Chen,Huizhen Xue,Zhoukun Li,Jinhui Lei,Muming Yu,Xin Yan,Hui Cao,Jie Zhou,Jiawei Liu,Mingna Zheng,Weiliang Dong,Yanwei Li,Zhongli Cui
Environmental pollution caused by plastic waste has become global problem that needs to be considered urgently. In the pursuit of a circular plastic economy, biodegradation provides an attractive strategy for managing plastic wastes, whereas effective plastic-degrading microbes and enzymes are required. In this study, we report that Blastobotrys sp. G-9 isolated from discarded plastic in landfills is capable of depolymerizing polyurethanes (PU) and poly (butylene adipate-co-terephthalate) (PBAT). Strain G-9 degrades up to 60% of PU foam after 21 days of incubation at 28 ℃ by breaking down carbonyl groups via secretory hydrolase as confirmed by structural characterization of plastics and degradation products identification. Within the supernatant of strain G-9, we identify a novel cutinase BaCut1, belonging to the esterase family, that can reproduce the same effect. BaCut1 demonstrates efficient degradation toward commercial polyester plastics PU foam (0.5 mg enzyme/25 mg plastic) and agricultural film PBAT (0.5 mg enzyme/10 mg plastic) with 50% and 18% weight loss at 37 ℃ for 48 h, respectively. BaCut1 hydrolyzes PU into adipic acid as a major end-product with 42.9% recovery via ester bond cleavage , and visible biodegradation is also identified from PBAT, which is a beneficial feature for future recycling economy. Molecular docking , along with products distribution, elucidates a special substrate-binding modes of BaCut1 with plastic substrate analogue . BaCut1-mediated polyester plastic degradation offers an alternative approach for managing PU plastic wastes through possible bio-recycling.
研究领域:
环境科学
·
微生物学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·Vol. 141
·期 31
·e55723
·
IF 2.7
Xiaoxuan Li,Zheng Yin,Yanru Zhao,Penghui Li,Shengli Wu
Isocyanate-based monomers and polymers have found widespread industrial application; however, the realization of green water-based products via the preparation of stable isocyanate aqueous emulsions remains challenging. Herein, a series of organosilicon and organofluorine synergistically modified amphiphilic branched polyurethanes (HBWPU), synthesized by grafting perfluorohexyl ethanol semi-terminated isophorone diisocyanate (IPDI) onto a hydrophilic polyurethane prepolymer, is presented. Subsequently, using a physical mixing method, stable diisocyanate emulsions are fabricated by preparing diisocyanate latex particles with IPDI as the core and hyperbranched water-based polyurethanes (HBWPU) as the shell. Structural investigations showed that the branching degree and fluorine content of the HBWPU significantly affects the stability of the diisocyanate emulsions. Increasing the degree of branching from 0.34 to 0.86 causes the amount of residual isocyanate ( NCO) groups to decrease from 20.1% to 16.7%. In contrast, an increase in the fluorine content from 0% to 17.8% increases the amount of residual NCO groups from 11.5% to 24.6%. Thus, HBWPU can be used as an emulsifier to prepare waterborne diisocyanate cross-linking agents. Such polyurethane-coated isocyanate aqueous emulsions can increase the hardness and significantly improve the acetone resistance of hydroxyl polyacrylate resins.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMER INTERNATIONAL
·
2020
·Vol. 69
·期 10
·985-994
·
IF 2.574
Meng Ma,Xinpeng Wang,Kai Liu,Si Chen,Yanqin Shi,Huiwen He,Xu Wang
The preparation of poly( l -lactic acid) (PLLA) with high mechanical and ideal flame-retardant properties is a great challenge. Herein, a simultaneous toughness and flame-retardant PLLA composite was successfully fabricated by using a one-step process which introduces 4,4′-methylenediphenyl diisocyanate and ammonium polyphosphate (APP) into PLLA/poly(ε-caprolactone) blends. SEM, Fourier transform infrared spectroscopy and TGA were adopted to confirm that APP participated in the in situ reaction during the melt process. The impact strength was increased to 13.5 kJ m −2 from 1.0 kJ m −2 for L8P2A5 composite, indicating the toughening effect of reactive blending. The cone calorimeter test, limiting oxygen index and vertical burning test results indicate that the flame-retardant properties of the composites are enhanced with increasing APP content. This work provides a method to prepare PLLA with high mechanical properties and enhanced flame retardancy. © 2020 Society of Chemical Industry
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2020
·
IF 2.627
Abid Ali,Lina Song,Jiankun Hu,Jingxian Jiang,Qingqing Rao,Muhammad Shoaib,Shah Fahad,Yongjie Cai,Xiaoli Zhan,Fengqiu Chen,Qinghua Zhang
In this work, a degradable polyurethane composed of caprolactone (CL) and L-Lactide (LLA) as soft segments, and 4,4′-methylenebis(cyclohexyl isocyanate) (H 12 MDI) and polytetramethylene ether glycol (PTMEG) as hard segments, was prepared. Hydrolytic degradation experiment revealed that the degradable polyurethane (PU) could be degraded in artificial seawater. It also showed that caprolactone-co-polyurethane (CL-PU) copolymer with higher crystallinity degraded much slower in artificial seawater. However, the introduction of LLA resulted in an increase in the hydrophilicity and reduction in the crystallinity of degradable PU, as demonstrated by the contact angle analysis. The result of the scanning electron microscope showed that the surface of degradable PU renewed under static condition. Moreover, degradable PU was able to be used as a carrier, and it controlled the release rate of 4, 5-dichloro-2-octyl-isothiazolone (DCOIT). The anti-diatom (Navicula incerta) test demonstrated that the (caprolactone-co-L-lactide)-co-polyurethane 4 (CL/LAx-PU4) with DCOIT contents prevented the adhesion of diatom Navicula incerta (88.37% reduction) due to their self-polishing and the release of antifoulants. Therefore, the degradable PU consisted of CL, LLA, and DCOIT could be a durable resin with good antifouling activity for the application in the marine anti-biofouling field.
研究领域:
材料科学
·
海洋生物学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2016
·Vol. 17
·期 4
·493
·
IF 3.257
Yongqiang Li,Jianwei Liu,Mei Lu,Zhiqing Ma,Chongling Cai,Yonghong Wang,Xing Zhang
Carboxylesterasesare an important class of detoxification enzymes involved in insecticide resistance in insects. A subgroup ofHelicoverpa armigeraesterases, known as Clade 001, was implicated in organophosphate and pyrethroid insecticide resistance due to their overabundance in resistant strains. In this work, a novel carboxylesterasegene001DofH. armigerafrom China was cloned, which has an open reading frame of 1665 nucleotides encoding 554 amino acid residues. We used a series of fusion proteins to successfully express carboxylesterase 001D inEscherichia coli. Three different fusion proteins were generated and tested. The enzyme kinetic assay towards 1-naphthyl acetate showed all three purified fusion proteins are active with aKcat between 0.35 and 2.29 s−1, and aKm between 7.61 and 19.72 μM. The HPLC assay showed all three purified fusion proteins had low but measurable hydrolase activity towardsβ-cypermethrin and fenvalerate insecticides (specific activities ranging from 0.13 to 0.67 μM·min−1·(μM−1·protein)). The enzyme was stable up to 40 °C and at pH 6.0–11.0. The results imply that carboxylesterase 001D is involved in detoxification, and this moderate insecticide hydrolysis may suggest that overexpression of the gene to enhance insecticide sequestration is necessary to allow carboxylesterases to confer resistance to these insecticides inH. armigera.Keywords:Helicoverpaarmigera;carboxylesterase;pyrethroid;heterologous expression
研究领域:
昆虫学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2024
·
IF 2
Muhammad Salman,Nimra Javed,Kun Hou,Asim Shakeel,Maogang He,Xiangyang Liu
To cope with stringent rules and criteria for engine performance and emissions, novel technologies must be developed to mitigate fuel’s polluting properties. Fatty acid alkyl esters, including methyl and ethyl esters, can be promising alternate surrogate fuels, including methyl butyrate, ethyl propionate, and ethyl acetate, due to their equipotential fuel nature. However, utilization is suggested for ethanol blends for their better performance and output. Therefore, thermophysical properties, such as the isobaric heat capacity of ethanol and biodiesel blends, can be essential for further property development. For this purpose, experimental isobaric heat capacity data of the ethanol and biodiesel blends with 50–50% mole fractions have been reported for ethanol + methyl butyrate, ethanol + ethyl propionate, and ethanol + ethyl acetate at a temperature range of 303.15–343.15 K and a pressure range of 0.1–20 MPa.
研究领域:
化学工程
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2012
·
IF 1.693
Xiaojing Li,Jiangtao Wu,Zhigang Liu
The thermal conductivity of 2-methoxyethyl acetate, 2-ethylhexyl acetate, and diethyl succinate in liquid phase was reported. The measurements of 2-methoxyethyl acetate and 2-ethylhexyl acetate, covering a temperature range from (233 to 373) K and pressure up to 20 MPa, have been performed by a transient hot-wire technique with two anodized tantalum hot wires. The measurements of diethyl succinate ranged from (263 to 383) K and atmospheric pressure to 20 MPa. The experimental data were represented by polynomial functions of pressure and temperature for the purpose of interpolation. The relative uncertainty of the present thermal conductivity data was estimated to be ± 2.0 % with a coverage factor of k = 2.
研究领域:
化学工程
·
物理化学
✓ 已验证
DOI
高影响因子
Materials Today Communications
·
2021
·
IF 3.383
Bushra Naureen,A.S.M.A. Haseeb,W.J. Basirun,Farina Muhamad
Tissue degeneration due to diseases, accidents, and wars is a worldwide issue. One of the methods used by regenerative medicine (RM) to aid tissue repair is by using a biodegradable tissue engineering scaffold (TES). Different body tissues have variable regeneration abilities, and hence, they require TES with variable degradation rates. This paper focuses on synthesising four polyurethane foam scaffolds (PUFS) with variable degradation rates based on the concentration of incorporated chain extender (CE) poly[(R)-3-hydroxybutyrate] (P3HB). The polyol employed is poly (propylene fumarate) (PPF) along with aliphatic 1,6-hexamethylene diisocyanate (HDI). GPC provided the molecular weight (M n = 455.67 g mol −1 , M w = 587.15 g mol −1 ) and PDI (1.29) of the PPF. FTIR and 1 H and 13 C NMR confirmed the proposed structures (C C, COOR, and NHCOO) of the PUFS. The FESEM images revealed a bimodal pore structure , with random, irregular, interconnected pores (242–340 µm) and discrete void spaces (735–860 µm). The size of PUFS pores and void spaces (PU4 > PU3 > PU2 > PU1) is directly proportional to their respective degradation rates. The TGA/DTA curves show a decrease of an onset thermal decomposition temperature from PU1 to PU4 (267.17 ºC PU1, 267.28 ºC PU2, 256.01 ºC PU3 and 240.72 ºC PU4) due to the respective increase in CE concentration. The results of in-vitro degradation analysis at day 70, revealed significant difference between the weight loss (%) of each group (PU1 = 4.09 ± 0.18%, PU2 = 8.03 ± 0.17%, PU3 = 13.14 ± 0.12% and PU4 = 20.21 ± 0.19%). Thus, PUFS with a higher concentration of P3HB have a faster degradation rate due to the associated P3HB hydrolysable ester/-COOR functional group within the PUFS backbone. The chemical structure , bimodal morphology, and variable degradation rate of these PUFS could be employed for various RM applications.
研究领域:
生物材料学
·
再生医学
·
高分子化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）