NORDIC PULP & PAPER RESEARCH JOURNAL
·
2022
·Vol. 37
·期 2
·300-310
·
IF 1.595
Jin-Jie Zhang,Ying-Ping Qi,Yong-Feng Shen,Hua Li
Paper cultural relics are both precious, inheritable and fragile. However, with the passage of time, paper will also be affected by a variety of factors, and will appear mildew, yellow, brittle, or even completely damaged. In order to protect the cultural relics, extend lifespan paper, CMC-acrylate-OVPOSS graft copolymerization emulsion was synthesized by using carboxymethyl cellulose (CMC) as substrate, methyl methacrylate (MMA), butyl acrylate (BA), glycidyl methacrylate (GMA), hydroxyethyl methacrylate (HEMA), octavinyl polyhedral oligomeric silsesquioxane (OVPOSS) as graft copolymer. The CMC-acrylate-OVPOSS emulsion was coated on the surface of the paper to test its protective effect on the paper. The results showed that the mass concentration of 10 % reinforcement solution coated on the paper, mechanical properties of paper were greatly improved, and the gloss and whiteness of paper were slightly changed, the paper also had a certain aging resistance and acid and alkali corrosion resistance. At the same time, the reversibility experiment showed that the reinforcement material had a certain reversibility.
研究领域:
材料科学
·
文物保护
·
高分子化学
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2017
·
IF 6.198
Xiaoqing Ye,Wuye Pan,Shilin Zhao,Yuehao Zhao,Yimin Zhu,Jing Liu,Weiping Liu
Although an acceleration of male pubertal development has been observed, precisely which endocrine-disrupting chemicals (EDCs) might contribute to the advancing onset of puberty in boys remains unclear. Here, pyrethroids, a class of widely used insecticides that have been considered as EDCs, are proposed as new environmental risk factors. In this study, 463 boys at the age of 9–16 years old were recruited in Hangzhou, Zhejiang, China. The common metabolites of pyrethroids, 3-phenoxybenzoic acid (3-PBA), and 4-fluoro-3-phenoxybenzoic acid (4-F-3-PBA), as well as gonadotropins, including luteinizing hormone (LH) and follicle-stimulating hormone (FSH), were analyzed in urine samples. Pubertal development was assessed based on Tanner stages and testicular volume (TV). A positive association between 3-PBA and gonadotropins was found (p < 0.001), in which a 10% increase in 3-PBA was associated with a 2.4% and 2.9% increase in LH and FSH, respectively. Higher urinary levels of 3-PBA in boys were associated with 275% and 280% increase in the risk of being genitalia stage 3 (G3) and G4, respectively (p < 0.05). There was a significant (132%) induction in odd of being TV 12–19 mL with increasing 3-PBA concentration compared to being in TV < 4 mL (p < 0.05). For the first time to our knowledge, this work reports on an association of increased pyrethroid exposure with elevated gonadotropins levels and earlier pubertal development in boys.
研究领域:
环境科学
·
内分泌学
·
公共卫生
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2019
·
IF 2.29
Zhijun Zhao,Ying Huang,Zhaohuan Zhang,Weiyang Fei,Mingsheng Luo,Yongsheng Zhao
Currently, solvent-based absorption is known as an effective technology to capture acid gases, e.g., CO 2 or H 2 S. In this work, the constant-volume method is used to determine CO 2 and H 2 S solubility in propylene carbonate (PC), imidazolium-based ionic liquids (ILs): 1-butyl-3-methylimidazolium tetrafluoroborate [Bmim][BF 4 ], 1-hexyl-3-methylimidazolium tetrafluoroborate [Hmim][BF 4 ], and 1-octyl-3-methylimidazolium tetrafluoroborate [Omim][BF 4 ], and their mixtures at temperature from 303.15 to 333.15 K under pressures up to about 1 MPa. Besides, the quantum chemistry-based COSMO-RS models are used to predict the vapor pressure and the solubility in these solvents. The experimental results illustrate that adding [Omim][BF 4 ] into PC can improve the CO 2 and H 2 S solubility and the H 2 S/CO 2 selectivity compared with the pure PC, which increases with the increasing [Omim][BF 4 ] mass fraction in the mixtures. The simulation with COSMO-RS shows the vapor pressures of PC in the mixtures decreases with the increasing [Omim][BF 4 ] mass fraction. Moreover, the prediction results show that COSMO-RS-Lei model is in much better agreement than COSMO-RS (ADF 2005) for predicting both CO 2 and H 2 S solubility and the prediction accuracy of CO 2 is better than that of H 2 S. Finally, the mixtures of PC and [Omim][BF 4 ] may be used as promising physical solvents to capture CO 2 and H 2 S selectively with high partial pressures because they connect the advantages of organic solvents and ILs.
研究领域:
化学工程
·
环境科学
✓ 已验证
DOI
高影响因子
ORGANIC PROCESS RESEARCH & DEVELOPMENT
·
2019
·
IF 3.327
Xin-peng Ma,Jin-sha Chen,Xiao-hua Du
Hymexazol is an efficient and low-toxicity soil fungicide. In this work, a fully continuous flow process for the synthesis of hymexazol has been developed. This process begins with combining ethyl acetoacetate and hydroxylamine hydrochloride to form a hydroxamic acid intermediate. The reaction solution is then quenched with concentrated hydrochloric acid to obtain the final product, hymexazol. Under the optimized process conditions, the total yield of the target product reached 86%. In addition, production was successfully scaled-up to a kilogram scale. The continuous flow method not only greatly decreases the reaction time but also significantly inhibits the side reactions.
研究领域:
化学工程
·
农药科学
✓ 已验证
DOI
高影响因子
Polymer Chemistry
·
2018
·Vol. 9
·期 21
·2880-2886
·
IF 4.927
Jiangjun Zhou,Mang Wu,Qiang Peng,Feng Jiang,Haowei Pan,Baoxia Wang,Shengquan Liu,Zhongkai Wang
Three easily performed and efficient strategies for preparing sustainable monomers and polymers derived from renewable fatty acids were investigated. All of these strategies relied on highly efficient esterification between halogenated compounds and fatty acids promoted by 1,1,3,3-tetramethylguanidine (TMG). In strategy 1, fatty acid-derived monomers and polymers were synthesized by TMG-promoted esterification of fatty acids with halogenated compounds followed by polymerization. In strategy 2, TMG-promoted esterification and polymerization reactions were performed in a one-pot process. In strategy 3, TMG-catalyzed esterification between halogenated polymers and fatty acids was conducted to obtain fatty acid-based sustainable polymers. 1H nuclear magnetic resonance and size-exclusion chromatography were used to characterize the as-prepared fatty acid based monomers and polymers. To demonstrate the versatility of these strategies, a series of fatty acid-based monomers was developed using various halogenated monomers. Moreover, reversible addition–fragmentation chain transfer (RAFT) polymerization was performed successfully on the prepared monomers.
研究领域:
材料化学
·
绿色化学
✓ 已验证
DOI
高影响因子
FLUID PHASE EQUILIBRIA
·
2014
·
IF 2.241
Guo-Min Yu,Li-Sheng Wang,Chao-Jun Du,Jian Sun
A phosphorous flame retardant of phosphoric acid , P , P ′-1,4-phenylene P , P , P ′, P ′-tetraphenyl ester (PAPTE) was synthesized by diphenyl chlorophosphate and hydroquinone . The structural features of PAPTE were investigated with mass spectra (MS), infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR) and high-performance liquid chromatograph (HPLC) methods. The thermal behavior of PAPTE was analyzed with differential scanning calorimeter (DSC) and thermogravimetric analysis (TGA) instruments. A static analytic method was used to measure the solubilities of PAPTE in the several selected pure solvents, which are methanol, ethanol, acetone, ethyl acetate , acetonitrile , methyl acetate , toluene, ether, n -propanol, i -propanol, where the temperatures range is from 288.25 to 333.45 K. The experiments were also performed in the binary mixed solvents of acetone and methanol. Several thermodynamic models were used to correlate the experimental solubility data, such as Wilson, nonrandom two-liquid (NRTL), UNIQUAC equations. The solubility data of PAPTE in binary solvents were correlated with the modified Wilson model. The calculated results showed that those models can excellently reproduce the experimental data and the UNIQUAC equation reveals the better ability in correlation. Using the Scatchard–Hildebrand methodology, the activity coefficients, solubility parameter of the solute and the partial molar excess enthalpies at infinite dilution were calculated.
研究领域:
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
MACROMOLECULES
·
2013
·
IF 5.521
Wenwen Yu,Miao Du,Dezhi Zhang,Yu Lin,Qiang Zheng
The effect of dangling chains on phase-separated microstructure and molecular dynamics for polyurethanes (PUs) was investigated. PUs with different dangling chain lengths and polar groups were prepared through changing the types of diol extender. The molecular dynamics was studied by a combination of dynamic mechanical analysis (DMA) and broadband dielectric relaxation spectroscopy (BDRS). Four relaxations (processes), namely, a secondary relaxation (β), the soft phase segmental relaxation (α), the I process associated with hydrogen bond, and Maxwell–Wagner–Sillars (MWS) interfacial polarization process caused by charge accumulation at hard/soft phase interfaces, were detected. The I process occurred in temperatures lower than that of MWS process but higher than α relaxation in general. The β relaxation remains unaffected with changing dangling chain lengths or polar groups. However, the glass transition temperature (Tg) of the soft phase shifts to lower temperature, and the segmental motion becomes faster with increasing dangling chain length, while the introduction of a polar ester group into the dangling chains makes it slow down, corresponding to a higher Tg, and results in a higher fragility. On the other hand, there is an absence of I process, and the MWS process shifts to higher frequencies when longer dangling chain is introduced. In the case of increasing the hard segment content, the I process reappears and the MWS process slows down. It is suggested that these results are related to the H-bond interactions within hard segments and the micromorphologies of PUs.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
Materials Today Communications
·
2022
·
IF 3.662
Feng Liu,Chunxiang Lu,Tongqing Sun
The poor wetting and spreading performances of waterborne polyurethane dispersion (WPUD) on carbon fiber (CF) surface limited its application in regulating the interfacial properties of CF reinforced polyamide 6 (PA6) composites. Unlike previous studies, this work diversified into improving the film-forming property of WPUD on CF surface. Two novel WPUD sizing agents named WPUD-Y1 and WPUD-F1 were synthesized by introducing block polyether and organic fluorine into the molecular chain. Results showed that surface energies of the elaborately designed WPUD-Y1 (35.5 mN/m) and WPUD-F1 (32.7 mN/m) were significantly lower than that of ordinary WPUD (40–55 mN/m). Especially, both sizings formed a complete and uniform film on CF surface. Interfacial shear strength (IFSS) analysis from micro-droplet test showed that sizing relieved the thermal residual stress at composite interphase by over 40 %, at the cost of reducing its interfacial strength by 20 %. More importantly, although sizing had not enhanced interfacial adhesion, the IFSS values between the sized CF and PA6 were still 20 % higher than the maximum interlaminar shear strength (ILSS) values reported in literatures.
研究领域:
材料科学
·
复合材料
✓ 已验证
DOI
高影响因子
FUEL
·
2021
·
IF 6.609
Yuewen Shao,Qingyin Li,Xinyi Dong,Junzhe Wang,Kai Sun,Lijun Zhang,Shu Zhang,Leilei Xu,Xiangzhou Yuan,Xun Hu
The production of γ-valerolactone (GVL) receives increasing attention due to its extensive applications as a promising fuel and fuel additive. In this study, the direct conversion of biomass-derived furfural to GVL with a unprecedent yield of 90.5% was achieved via consecutive hydrogenation and acid-catalyzed reactions over CuAl for hydrogenation and a co-catalyst (i.e. H-ZSM-5) for acid-catalysis in ethanol. The relative abundance of the hydrogenation sites and acidic sites determines the reaction network and the transfer of the main products from furfuryl alcohol (FA) to ethyl levulinate (EL) or GVL, as the acidic sites, especially the Brønsted acidic sites, not only catalyze the formation of EL from FA, but also affect the hydrogenation activity of CuAl. However, the Lewis acidic sites facilitate the opening ring of FA to 1,4-pentanediol, preventing the GVL formation. The acid catalyst and hydrogenation catalyst deactivate via varied mechanisms in the conversion of furfural to GVL, which is required to be considered in the further development of the robust catalysts.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2022
·Vol. 57
·期 4
·2597-2609
·
IF 4.682
Zhai Wangyi,Cao Yuanming,Li Yifei,Zheng Min,Wang Zuoshan
The exploration of novel and multifunctional coatings through composite nanomaterials design is crucial for developing next-generation polyester fabrics. Herein, we report an efficient approach of self-assembling MoO 3– x QDs on MXene (Ti 3 C 2 T x ) to fabricate multifunctional polyester fabrics. In a typical preparation, MoO 3– x QDs with an average size of 5 nm were uniformly distributed on the surface of MXene nanoflakes upon UV light. Then, polyester fabrics were coated with MoO 3– x QDs/MXene by dipping. The results demonstrated that the coated fabric had a decreasing trend in the electrostatic half-period from more than 60 s (untreated fabric) to 0.15 s and had excellent washing fastness. In addition, a similar phenomenon was found in smoke suppression, with the coated fabric producing 36.16% less smoke. More importantly, the sterilization rate of the coated fabric had reached 99% to E. coli and S. aureus under sunlight owing to the strong response of MoO 3– x QDs/MXene. This work provides a novel and facile strategy to design multifunctional coatings.
研究领域:
材料科学
·
纺织工程
·
纳米技术
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2016
·Vol. 40
·期 6
·5170-5176
·
IF 3.277
Bibimaryam Mousavi,Somboon Chaemchuen,Behrooz Moosavi,Zhixiong Luo,Nadia Gholampour,Francis Verpoort
Zeolitic imidazole framework (ZIF)-67 is an efficient heterogeneous catalyst for the cycloaddition of carbon dioxide to epoxides to afford cyclic carbonates. In this work, ZIF-67 was synthesized by a simple and straightforward method at room temperature. The coupling reaction in the presence of ZIF-67 without any co-catalyst or solvent was studied under different conditions. The reaction conversion was more than 99% and the selectivity toward chloropropene carbonate was considerably higher (>99%) than the previously reported ZIF-8. Moreover, the ZIF-67 catalyst could be recycled at least four times without noticeable loss of catalytic activity.
研究领域:
化学
·
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
Polymers
·
2020
·Vol. 12
·期 2
·326
·
IF 3.426
Qiwen Yong,Jinming Chang,Qi Liu,Feng Jiang,Daidong Wei,Haijun Li
Matt polyurethane coating was successfully prepared through the synergistic effect of castor oil and phenolic epoxy resin into polyurethane backbone. The formation mechanism may be ascribed to the modulus mismatch between the partially modified epoxy polyurethane and partially unmodified polyurethane. Scanning electron microscopy (SEM) was used to observe the micro-rough surface morphologies. Atomic force microscopy (AFM) and three-dimensional (3D) surface profilometer were applied to calculate a series of surface roughness parameters in different dimensions, such asSa,Sq,Sp,Sv,Sz,Sku,Ssk, etc. The exciting results of this paper—the correlation of surface roughness on measurement length and gloss—are explored in detail. It reveals the extrinsic property of measured roughness with measurement length and provides guidance for what kind of incident angle gloss meters (20°, 60°, and 85°) best describe the gloss of matt polyurethane coating.
研究领域:
材料科学
·
表面工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）