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41.
Owing to lack of proper recycling methods, plastic flexible film wastes are usually directly discarded or incinerated, which brings about severe environmental pollution. Therefore, converting plastic wastes into value‐added products has received more and more attention in recent years. In this work, paper‐like composites derived from plastic flexible film wastes were prepared via the thermally induced phase separation method by adding polyethylene‐graft‐maleic anhydride (PE‐g‐MAH) as a compatibilizer and fumed silica as an additive. The resulting paper‐like composites were characterized by SEM and infrared spectroscopy. Other properties such as mechanical properties, thermal properties, whiteness, printability and adsorption performance were also tested in detail. It was found that remarkable enhancements in mechanical, thermal and printable properties of the paper‐like composites were obtained when nano‐SiO2 loading was 2.5–3 wt%. Uniformly distributed holes that can endow good printability by providing space for ink or other functional molecules were observed by using SEM. Furthermore, the CIE whiteness value of the resulting composites can reach 91.6%–96.7% on adding nano‐SiO2. Additionally, the paper‐like composites integrating nano‐SiO2 and PE‐g‐MAH exhibited good solid ink affinity and high water or oil adsorption capacity. Thus, according to this research, high‐performance printable paper‐like composites used as major components of multifunctional papers can be prepared based on plastic flexible film wastes. © 2019 Society of Chemical Industry 相似文献
42.
借助全自动淬火膨胀仪测定钢的Ac1、Ac3相变点,通过对试验钢进行淬火+亚温淬火+回火热处理和淬火+回火热处理,研究了两种热处理工艺下30MnCrNiMo高强钢的组织与性能。结果表明:30MnCrNiMo高强钢的Ac1、Ac3相变点分别为653、807 ℃。采用淬火+亚温淬火+回火的热处理工艺所获得的马氏体和铁素体复相组织比直接淬火+回火得到的全马氏体组织更为细小、均匀,试验钢的屈服强度为1499 MPa,伸长率为14.0%,室温、-40 ℃冲击吸收能量分别为35.5和29.5 J,钢的塑性和冲击性能显著提升,有效改善了30MnCrNiMo高强钢的强韧性能。 相似文献
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Miaomiao Zhang Xuepei Miao Jianwei Fu Fei Bao Xing An Lifan He Xiaoyu Li Yan Meng 《Polymer International》2020,69(9):867-875
Non‐amine‐derived tetrafunctional epoxies have several advantages over the amine‐derived N,N,N′,N′‐tetraglycidyl‐4,4′‐diaminodiphenyl methane (TGDDM) in high temperature applications. Although two non‐amine‐derived tetrafunctional epoxies were developed in our laboratory, further improvements in toughness using less loading amount is still desirable. Thus, a tertiary‐amine‐free, non‐planar and triphenylmethane‐containing tetrafunctional epoxy (STFE) with a sulfone spacer was synthesized. When it was mixed with diglycidyl ether of bisphenol A (DGEBA) and cured with 4,4′‐diaminodiphenylsulfone (DDS), both thermal and mechanical performances outperformed TGDDM. Moreover, STFE modified system shows the highest toughness (35.7 kJ m–2) among three amine‐free and triphenylmethane‐containing epoxies at merely 5 wt% loading. Molecular simulation and thermomechanical analysis results suggest that the improved mechanical properties could be related to the geometry of the molecule and larger free volume. Despite a marginal drop in Tg, the thermal degradation temperature is better than that of TGDDM/DDS. In addition, the moisture resistance of STFE/DGEBA/DDS is much better than that of TGDDM/DDS. Thus, STFE modified DGEBA could be a potential replacement for TGDDM in some high temperature applications. © 2020 Society of Chemical Industry 相似文献
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Jun Wang Ziyang Gao Hongtao Fu Guangya Ding Yuanqiang Cai Xueyu Geng Changxin Shi 《Geotextiles and Geomembranes》2019,47(2):121-127
The results from three laboratory model tests performed under various vacuum and surcharge loads with PVDs are reported. Different SLRs were adopted to investigate the effect on the consolidation of dredged soil. To measure the lateral displacement, a refitted inclinometer was developed and tested. In the tests, the settlement, lateral displacement, and vane shear strength were measured, and the degree of consolidation (DOC), horizontal coefficient of consolidation (Ch), and bearing capacity were calculated. The results indicate that larger SLR values promote consolidation. The largest vane shear strength, settlement, and Ch values were all obtained under the highest SLR, and the bearing capacity under this SLR was more than double that under the lowest SLR. The DOC was found to increase with the growth of the SLR. However, considering the vacuum pressure was higher in Case-III, the influence of SLR on reinforcement effect may not be so significant. 相似文献
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Hai Huang Haichao An Haibo Ma Shenyan Chen 《International journal for numerical methods in engineering》2019,117(3):291-315
This work presents an engineering method for optimizing structures made of bars, beams, plates, or a combination of those components. Corresponding problems involve both continuous (size) and discrete (topology) variables. Using a branched multipoint approximate function, which involves such mixed variables, a series of sequential approximate problems are constructed to make the primal problem explicit. To solve the approximate problems, genetic algorithm (GA) is utilized to optimize discrete variables, and when calculating individual fitness values in GA, a second-level approximate problem only involving retained continuous variables is built to optimize continuous variables. The solution to the second-level approximate problem can be easily obtained with dual methods. Structural analyses are only needed before improving the branched approximate functions in the iteration cycles. The method aims at optimal design of discrete structures consisting of bars, beams, plates, or other components. Numerical examples are given to illustrate its effectiveness, including frame topology optimization, layout optimization of stiffeners modeled with beams or shells, concurrent layout optimization of beam and shell components, and an application in a microsatellite structure. Optimization results show that the number of structural analyses is dramatically decreased when compared with pure GA while even comparable to pure sizing optimization. 相似文献
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Wireless Networks - The legacy long term evolution (LTE) networks suffer from scalability problems when a massive number of Internet of Things devices enter the network simultaneously. In this... 相似文献