Polymer Chemistry
·
2022
·Vol. 13
·期 8
·1098-1106
·
IF 5.364
Junjin Duan,Yi Gong,Dong Chen,Yuhong Ma,Changtong Song,Wantai Yang
In this study, we develop a direct, thermally initiated radical homopolymerization of vinyl ethers mediated by lithium salts CH3OLi and LiI. In the case of vinyl ether monomers having a hydroxyl group, for example, diethyleneglycol monovinyl ether (DEGV), a high molecular weight poly(DEGV) (Mn = 18 700) is produced in a high yield (≥68%) with negligible acetal formation. Most importantly, this method further enables the radical polymerization of alkyl vinyl ether (IBVE) which has no hydroxyl group to form hydrogen bonds to facilitate the radical polymerization. There are no evident structural defects caused by side reactions such as β-scission and hydrogen abstraction as the poly(IBVE) yield is up to about 50% and Mn = 8500. Under similar conditions, the poly(IBVE) yield of the control run is only 16.2%. Density functional theory calculations suggest that the interaction between Li+ and CC–O of IBVE significantly reduces the HOMO–LUMO energy gap from 6.83 eV to 4.61 eV. In addition, the changes in 1H-NMR chemical shifts of CH2CH–O– further support the existence of interaction between Li+ and CC–O. This cation-π complexation between Li+ and vinyl ether can effectively reduce the electron density of the vinyl group and as a result increases the stability of σ-radicals and suppresses unfavorable side reactions.
研究领域:
高分子化学
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材料科学
·
物理化学
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产品关联
DOI
高影响因子
Nanoscale Research Letters
·
2018
·Vol. 13
·期 1
·1-8
·
IF 3.125
Yue Tian-Tian,Li Xiao,Wang Xiao-Xiong,Yan Xu,Yu Miao,Ma Jian-Wei,Zhou Yu,Ramakrishna Seeram,Long Yun-Ze
Electrospinning provides an effective method for generating nanofibers from solution of carboxymethyl chitosan/polyoxyethylene oxide (CMCS/PEO). The goal of this work is to explore the potential application of electrospun CMCS/PEO nanofiber membrane in fruit fresh-keeping. The microstructure, antibacterial activity, hydrophilia, and air permeability of the nanofiber membrane have been tested. For comparison, the fresh-keeping effects of commercial cling wrap and CMCS/PEO nanofiber membranes on strawberries’ rotting rate and weight loss rate have been studied. The results indicate that the electrospun CMCS/PEO membrane could effectively avoid water loss in strawberries and has a remarkable effect to prolong strawberries’ shelf life due to its breathability and antibacterial activity. In addition, the composite CMCS/PEO, nanofiber membrane is non-poisonous and edible, which can be used in food industry.
研究领域:
食品科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2019
·
IF 4.784
Tao Zheng,Dingming Zhong,Dafeng Zheng,Fengli Bao,Jianmin Zheng,Xueqing Qiu
In order to develop a biomass-based superplasticizer, kraft lignin (KL) was grafted with isopentenol polyoxyethylene ether (TPEG) to prepare a novel macromonomer (KL-TPEG). It was shown that the retention ratio of the aliphatic C C bond increased from 81.07% to 90.20% with the increase of m(TPEG)/m(KL). When the grafting ratio was increased, the average number of TPEG grafted on one KL molecule was approximately 1.4, 3.1, 4.6, 6.2 and 7.6. The star-like structure was also confirmed by FT-IR, 1 H NMR and GPC. KL-TPEG had favorable surface activity and dispersion stability on the cement particles. It was illustrated that the shear stress and shear viscosity of the cement slurries with KL-TPEG were significantly less than that of blank slurry. The dispersion-retention ability of KL-TPEG on the slurry was also gradually enhanced with the increase of the grafting ratio of TPEG. It was seldom reported on the biomass-based TPEG. Through modified with KL, the rheology behavior and the dispersion-retention ability of TPEG was greatly improved, and the cost of TPEG was also reduced, thus this study not only promoted the development of biomass-based macromonomer, but also helped for the high value utilization of lignin.
研究领域:
材料科学
·
生物质化学
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产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2021
·Vol. 28
·期 28
·37781-37792
·
IF 4.223
Wang Dan,Lou Jiangfei,Xu Jin,Yuan Jiugang,Wang Qiang,Wang Ping,Fan Xuerong
Alkylphenol polyethoxylates (APEO n ) are the second-largest category of commercial nonionic surfactants, which are difficult to degrade naturally in the environment. This study examined the degradation of octylphenol polyethoxylate (OPEO n ) by laccase and its laccase-mediated systems. The results showed that OPEO n was poorly degraded by laccase alone. 2, 2′-azino-bis [3-ethylbenzothiazoline-6-sulphonic acid] (ABTS), 1-hydroxybenzotriazole (HBT), and 2, 2, 6, 6-tetramethylpiperidine-1-oxyl (TEMPO) were selected as the redox mediators. Experimental results also indicated that 52.4% of the initial OPEO n amount was degraded by laccase in the presence of TEMPO. The degradation efficiency was analyzed using high-performance liquid chromatography. Furthermore, the structural characteristics of the degradation products were measured using matrix-assisted laser desorption/ionization-time of flight mass spectrometry and nuclear magnetic resonance spectroscopy, and it could be found that the laccase-TEMPO system could gradually shorten the ethoxylate chain by oxidizing the primary hydroxyl group of OPEO n , thereby degrading the OPEO n of the macromolecule into small molecules. The maximum of the ion peak distributions of OPEO n decreased from n = 8 finally down to 3. The novel enzymatic system introduced by this study will become a promising alternative method for high-efficiency APEO n conversion and had great potential value in wastewater treatment. Graphical abstract
研究领域:
环境科学
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生物化学
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产品关联
DOI
PubMed
高影响因子
Atmosphere
·
2018
·Vol. 9
·期 10
·401
·
IF 1.704
Chen Lv,Lin Du,Narcisse T. Tsona,Xiaotong Jiang,Wenxing Wang
Rate coefficients at ambient temperature and atmospheric pressure for the reaction of ozone with 2-methoxypropene (2-MPE) and 2-ethoxypropene (2-EPE) were determined in an evacuable 100 L Teflon reaction chamber using absolute and relative rate methods. The product experiments were carried out using a 50 L Teflon reaction chamber in conjunction with FTIR as the detection technique. The rate coefficients (kin units of cm3molecule−1s−1) obtained are 1.18 ± 0.13 × 10−17and 1.89 ± 0.23 × 10−17for reactions with 2-MPE and 2-EPE, respectively. The effects of the alkoxy group on the gas-phase reactivity of alkyl vinyl ethers toward ozone are compared and discussed. The major ozonolysis products are methyl acetate, formaldehyde and CO2for 2-MPE, and ethyl acetate, formaldehyde and CO2for 2-EPE. Possible mechanisms for the two vinyl ethers are proposed based on the observed reaction products. Additionally, atmospheric lifetimes of 32 h and 21 h for 2-MPE and 2-EPE were estimated based on the measured rate constants and the ambient tropospheric concentration of ozone, respectively. The obtained values of the lifetimes indicate that the reaction with ozone is an important loss process for these vinyl ethers in the atmosphere, especially in polluted areas.Keywords:vinyl ethers;rate coefficient;absolute and relative kinetics;mechanism;atmospheric implications
研究领域:
大气化学
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环境科学
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DOI
高影响因子
International Journal of Refrigeration
·
2019
·
IF 3.177
Tao Jia,Shengshan Bi,Jiangtao Wu,Panyuan Li
Experimental solubilities of difluoromethane (R32) in polyol ester (POE), polyvinylether (PVE), and polyalkylene glycol (PAG) base oils were measured in the temperatures range from 273 K to 351 K based on the isochoric method. The experimental setup was checked by measuring the solubility of carbon dioxide in n -decane at pressures from 0.1 to 4.6 MPa. The expanded uncertainty ( k = 2) of the measured solubility data was estimated to be less than 2.8%. The experimental solubility data were correlated using the Peng–Robinson (PR) equation of state (EOS) and Wilson activity coefficient model. The absolute average deviations of the experimental data and calculated values for R32 in POE, PVE, and PAG base oils were 1.74%, 0.73%, and 0.97%, respectively. The solubility of R32 in three base oil were calculated and compared at same temperatures and pressures, and the results showed that the solubility order of R32 in the three base oils was: PAG > PVE > POE.
研究领域:
化学工程
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制冷技术
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产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2024
·
IF 5.3
Jiajun Li,Shaoqi Kong,Guochao Yan,Xuanlai Chen
The serious hazards posed by inhalable coal dust to the safety, air purity, and health of coal miners can be effectively alleviated through the use of appropriate dust suppressants. The wetting enhancement capabilities of two dust suppressants, octylphenol polyoxyethylene ether (OP-10) and nonylphenol polyoxyethylene ether (NP-10), were examined in this study through experimental and simulation methods. Macroscopic experiments (surface tension, contact angle, coal dust settling time, and water retention) indicate that the shorter the alkyl chain attached to the benzene ring in the surfactant and the lower the surface tension, the more conducive it is to improving the fluidity and suspension stability of anthracite particles in the wetting solution and further improving the interfacial properties and wetting effect between coal dust and the liquid medium. Mesoscopic experiments (laser particle size, FTIR, XPS, UV–visible spectroscopy, BET, and SEM) showed that the relevant properties of APEO-modified coals were greatly changed, especially the anthracite modified with short-chain alkyl groups of OP-10, which exhibited a stronger aggregation effect on the coal dust particles and increased the pore structure and specific surface area of the coal dust. Additionally, the hydrophilic functional groups are augmented, leading to a notable enhancement in the adsorption capacity of OP-10 on the coal surface. Microscopic simulations (Density Functional Theory calculations, Molecular Dynamics simulations) reveal that APEO surfactants with longer alkyl side chains attached to benzene rings hinder the π-π interactions between the coal's aromatic ring structures and the benzene rings in the surfactants. The surface polarity of coal modified with OP-10 is significantly enhanced, resulting in a more pronounced improvement in wetting performance and an increased water retention capability. The study systematically explores surfactant microstructure effects on anthracite wetting, laying essential groundwork for advanced dust suppression system development.
研究领域:
环境科学
·
材料科学
·
计算化学
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产品关联
DOI
高影响因子
Polymer Chemistry
·
2017
·Vol. 8
·期 17
·2713-2722
·
IF 5.375
Jia Wang,Baixue Li,Dehua Xin,Rongrong Hu,Zujin Zhao,Anjun Qin,Ben Zhong Tang
The polyhydroXations, such as polyhydrothiolation and polyhydroamination, of alkynes have been well-established. However, the polyhydroalkoxylation is rarely reported. In this paper, the polyhydroalkoxylation of aromatic diynes was successfully developed in the presence of a superbase, phosphazene base (t-BuP4). A series of soluble and regio-regular anti-Markovnikov additive poly(vinyl ether)s with high molecular weights (Mw up to 40 600) were obtained in high yields (up to 99%). All the polymers are thermally and morphologically stable. The tetraphenylethene (TPE)-containing P1a2a, P1a2b and P1a2c showed unique aggregation-enhanced emission (AEE) characteristics, and their aggregates could be used for explosive detection with a superamplification quenching effect. The poly(vinyl ether)s are degradable under acidic conditions. Thus, this work not only established a new polymerization but also generated a series of functional polymeric materials that are potentially applicable in optoelectronic and biomedical fields.
研究领域:
化学
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材料科学
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高分子化学
✓ 已验证
DOI
高影响因子
JOURNAL OF POLYMER SCIENCE
·
2025
·Vol. 63
·期 8
·1947-1957
·
IF 3.6
Jiaying Tong,Dan Zhao,Jingwen Yao,Dong Chen,Junjin Duan,Yuhong Ma,Wantai Yang
First thought, we tried hexafluoroisopropanol (HFIP) as the hydrogen bonding donor and LiI as a mediator to promote the radical homopolymerization of vinyl ethers. Unexpectedly, an exothermic reaction and significant viscosity increase were observed as the monomer conversion of isobutyl vinyl ether (IBVE) up to 90% at 0°C in the absence of a radical initiator. Therefore, we speculated that it was a cationic rather than a radical polymerization and confirmed with the proton trapping agent 2,6-di-tert-butylpyridine. With anhydrous CH 2 Cl 2 as a solvent, the molecular weights of the PIBVE are in the range of 5900–8900. With a decrease in the reaction temperature to −20°C, the molecular weight distribution is in the range of 1.74–1.19. Moreover, 2-ethylhexyl vinyl ether (EHVE) and cyclohexyl vinyl ether (CHVE) could also undergo a similar polymerization. A plausible cationic polymerization mechanism is proposed that vinyl ethers are initiated by H + which is generated by the reaction of HFIP and LiI. The end groups of PIBVE are composed of -H at the α-end and an aldehyde group -CH 2 CHO (I) or an acetal group -CH 2 CH(OCH 2 CH(CH 3 ) 2 ) 2 (II) at the ω-end. In addition, the end groups for PEHVE and PCHVE are consistent with the above mechanism. Graphical
研究领域:
材料科学
·
高分子化学
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产品关联
DOI
高影响因子
ACS Applied Polymer Materials
·
2022
·
IF 4.855
Xia Lin,Jiajia Li,Na Li,Xiangqiang Pan,Zhengbiao Zhang,Jian Zhu
Poly(vinyl ether)s (PVEs) are typical products from living cationic polymerization. However, postpolymerization modification (PPM) and topological structure design of poly(vinyl ether)s under relatively mild conditions are rare, which limits their practical applications. Herein, we report a facile method to overcome this limitation by exploiting the selective addition reaction of electrophilic selenium reagent and divinyl monomers, which can produce PVEs with pendent vinyl groups in each repeat unit or end-functionalized PVEs. PPM of PVEs was realized by a thiol–ene click reaction. Furthermore, brush polymers and core cross-linked star polymers were successfully prepared by using end-functionalized PVEs as macromonomers, providing a general method for the preparation of topological polymers and laying a foundation for the development and application of PVEs.
研究领域:
高分子化学
·
材料科学
✓ 已验证
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2021
·
IF 5.909
Dan Wang,Ruofei Zhu,Jiangfei Lou,Jiugang Yuan,Jin Xu,Xuerong Fan
Alkylphenol polyethoxylate (APEO n ) is an emerging contaminant mainly referred to nonylphenol polyethoxylate (NPEO n ) and octylphenol polyethoxylate (OPEO n ). A novel multiscale rough composite photocatalyst (CuO@Cu-H 3 BTC) with marigold-flower nanosheets and sub-micron flakes was successfully constructed for photodegradation of OPEO n and NPEO n under visible light. Several technologies (such as SEM , EDS, FTIR, XRD, XPS and EPR) were utilized to characterize the structures and properties of the as-obtained sample. The effect of OPEO n and NPEO n removal by CuO@Cu-H 3 BTC MOF and the influence of reaction conditions on the removal efficiency were explored. It was found that 96% of OPEO n and 79% of NPEO n were removed under the action of adsorption in darkness and degradation in visible light irradiation within 120 min when treating 25 mg/L OPEO n and NPEO n solution with 1.6 g/L of CuO@Cu-H 3 BTC MOF composite. The corresponding OPEO n and NPEO n removal efficiency could still achieve almost 72% and 51% after the CuO@Cu-H 3 BTC MOF was recycled five times, respectively. The degradation mechanism of APEO n investigation revealed that the free radicals and holes generated in the CuO@Cu-H 3 BTC MOF degraded APEO n , and the existence of holes was confirmed to play the major role through quenching experiment. In summary, this facile and novel CuO@Cu-H 3 BTC MOFs composite photocatalyst boosts the application platform in wastewater treatment .
研究领域:
环境科学
·
材料科学
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DOI
高影响因子
BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY
·
2014
·Vol. 93
·期 2
·204-208
·
IF 1.216
Hu Xue-lei,Sun Zhi-wei,Wang Jing-jing,An Min,Duan Shun-shan
The aim of this paper was to examine the sublethal toxic effects of nonylphenol ethoxylate (NP 10 EO), its primary degradation product nonylphenol (NP), and their mixture on Moina macrocopa . Chronic toxicity tests were carried out by using sublethal chemical concentrations. Results showed that all treatments reduced the survivorship, body length, and reproduction of M. macrocopa with NP being 10 %–20 % more toxic to M. macrocopa than NP 10 EO. Results also indicated that the toxic effects of NP 10 EO and NP mixture on M. macrocopa were more severe than that of any single chemical alone. At the highest concentration in this experiment, 0.337 mg L −1 NP 10 EO plus 0.0154 mg L −1 NP treatment caused the survivorship of M. macrocopa to zero, neonates number of reproductions to zero, 45.5 % reduction in the body length, and 88 % reduction in the total neonates number.
研究领域:
环境科学
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）