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排序方式: 共有189条查询结果,搜索用时 171 毫秒
61.
Dongmin Li Bao Zhang Xing Ou Jiafeng Zhang Kui Meng Guanjun Ji Pengfei Li Jianhui Xu 《中国化学快报》2021,32(7):2333-2337
In this paper, the ammonia leaching process and high-energy ball milling method were adapted to recover spent LiCoO2 material. The ammonia reduction leaching mechanism of LiCoO2 material in the ammonia-sodium sulfite-ammonium chloride system was elucidated. Compared with untreated LiCoO2 material, the leaching equilibrium time of LiCoO2 after ball-milled for 5 h was reduced from 48 h to 4 h, and the leaching efficiency of lithium and cobalt was improved from 69.86% and 70.80% to 89.86% and 98.22%, respectively. Importantly, the apparent activation energy and leaching kinetic equation of the reaction was calculated by the shrinking core reaction model, indicating that the reaction was controlled by the chemical reaction. 相似文献
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63.
This work analyses the rheological behaviour of thermoplastic elastomeric blends (TPE) based on ground tyre rubber (GTR), more specifically the rheological behaviour of binary and ternary polypropylene (PP) based blends with different rubber materials: an ethylene propylene diene monomer (EPDM), an ethylene propylene rubber (EPR) and GTR. The study was developed under steady-shear rate conditions by capillary rheometry at three different temperatures. Time–Temperature Superposition Principle (TTSP) was applied to the viscosity curves using a temperature dependent shift factor, allowing the construction of master curves for the analysed blends. The Cross-WLF model was used to predict the rheological parameters, giving numerical results for viscosity similar to the experimental data. GTR increased the blends viscosity. EPR showed rheological behaviour similar to PP, and EPDM presented higher power law behaviour. Pseudoplastic behaviour was observed for all the analysed blends. Incorporation of GTR in TPE blends for injection moulding purposes was found to be a feasible strategy to upcycle this type of potentially wasted material. 相似文献
64.
We improved the recyclability of mixed poly(ethylene-terephthalate) (PET) and poly(lactic acid) (PLA) bottle waste. We made uncompatibilized and compatibilized PET/PLA blends of different weight ratios with a twin-screw extruder. Then, we analysed the mechanical properties, the miscibility and the thermal stability of the blends with and without compatibilizers. From the change in intrinsic viscosities (IV), we concluded that different reactions occur between the polymer chains due to the compatibilizers. We observed that when ethylene-butyl acrylate-glycidyl methacrylate (E-BA-GMA) as compatibilizer was added, the blends became tougher; elongation at break and Charpy impact strength increased, but Young's modulus of the blends decreased. In addition, the compatibilizers improved the thermal stability of the blends and this may have been caused by a number of mechanisms. 相似文献
65.
Alain Bourmaud Antoine Le DuigouChristophe Baley 《Polymer Degradation and Stability》2011,96(10):1732-1739
The integration of the environmental problem in the design of industrial products leads us to incorporate vegetal fibres and recycled polymers into composite materials. The aim of this work is to study the behaviour and the environmental interest of a recycled PP/hemp fibre after several injection cycles. The mechanical and rheological behaviour of recycled PP/hemp composite was first studied by using tensile, dynamical mechanic analysis and rheological measurements. Then, to better understand the influence of the recycling, a morphology study was carried out on composites by using optical and electron microscopy. Finally, we investigated the environmental advantages of our composite thanks to a simplified environmental assessment. Our results highlighted the environmental interest of using a recycled matrix to prepare composites reinforced with vegetal fibres and the interesting properties of this material after recycling. 相似文献
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67.
Polymer-bound sulfonylhydrazide was prepared from commercial sulfonic acid resin through a straightforward, one-step synthetic route avoiding chlorosulfonic intermediates. The simplex self-directing optimization method was used to determine rapidly the ideal operating conditions under microwave irradiation. Polymer-bound sulfonylhydrazide has found an application as scavenging agent in winemaking therefore, this clean preparative approach is expected to be more acceptable by winemakers. An efficient recycling protocol of the used supports has also been established. 相似文献
68.
The use of fluorous ammonium salts as metal-free catalysts for the direct condensation of equimolar amounts of carboxylic acids and aliphatic alcohols has been investigated. Esterification reactions were thus conveniently carried out under mild fluorous biphasic conditions, in the presence of 1 mol % of fluorous ammonium triflate and without recourse to any additional water removal technique. Good to excellent ester yields were obtained in the case of primary and secondary aliphatic alcohols. The fluorous salt was easily recovered by simple phase separation and reused at least three times without considerable loss of activity. 相似文献
69.
Anne M. Arink 《Journal of organometallic chemistry》2004,689(23):3813-3819
An aminoarenethiolato copper(I) catalyst was attached to a carbosilane dendritic wedge, which had been prepared via a novel convergent synthetic method. Compared with the unsupported complex, this novel dendritic copper(I) catalyst is more robust towards hydrolysis and oxidation and has increased solubility in common organic solvents. The catalytic activity of the dendritic copper catalyst was tested in the 1,4-addition of Et2Zn to 2-cyclohexenone. In both polar (Et2O) and apolar (hexane) solvents excellent activity was observed. The fact that the catalytic copper site remains attached to the nanosize dendritic aminoarenethiolate ligand allows separation of this catalyst by means of nanofiltration. 相似文献
70.
Chang-Eun Yeom 《Tetrahedron letters》2007,48(51):9035-9039
Ionic liquid was found to be an excellent medium for asymmetric Diels-Alder reaction catalyzed by chiral bis(oxazoline)-copper complex. The reactivity and selectivity of reactions were highly dependent upon the property of the ionic liquids. Reactions of β-substituted acryloyl dienophiles in [Bmim]SbF6 at ambient temperature provided remarkably enhanced reactivity and stereoselectivity compared to homogeneous reactions in non-ionic liquid solvent at −78 °C. Due to the increased reactivity, the amount of metal catalyst could be reduced down to 0.6 mol % without any significant selectivity compromise. Additionally, recycling of the ligand-metal complex was achieved efficiently up to 18 times. 相似文献