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石蜡或聚丁二烯填充型高吸油树脂的合成及其性能比较 总被引:3,自引:0,他引:3
以过氧化二苯甲酰 (BPO)为引发剂、二甲基丙烯酸乙二酯 (EGDMA)为化学交联剂、甲基丙烯酸十二酯 (DMA)和苯乙烯 (St)为单体、石蜡 (Paraffin)或聚丁二烯 (PB)为填充剂 ,用悬浮聚合法合成了填充型高吸油树脂 .研究了单体配比、填充剂用量以及化学交联度对树脂吸油性能及凝胶分率的影响 .对石蜡和PB填充的高吸油树脂进行比较 ,发现PB填充的高吸油树脂中存在物理交联 ,而石蜡填充的树脂中不含物理交联 ;PB填充的高吸油树脂随PB用量的增加 ,吸油倍率提高 ,凝胶分率上升 ,脱油速率增大 ;而石蜡填充的树脂随石蜡用量的增加 ,吸油倍率提高 ,但凝胶分率和脱油速率变化不大 相似文献
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速吸油型高吸油性树脂的研究 总被引:6,自引:0,他引:6
以丙烯酸-2乙基己酯与甲基丙烯酸异丁酯为单体,采用加入一种惰性溶剂的悬浮聚合法合成了多孔性高吸油性树脂。在单体中基丙烯酸异丁酯含量为27%以及引发剂为1%和交联剂为0.5%的条件,制得的树脂吸油速度在1小时内达最大值;可以吸其自身重量10倍的煤油、18.2倍的苯。 相似文献
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甲基丙烯酸十二酯精制及其树脂性能研究 总被引:1,自引:0,他引:1
对工业级甲基丙烯酸十二酯单体进行了精制提纯,采用悬浮聚合法合成了甲基丙烯酸十二酯树脂。利用傅立叶变换红外光谱(FTIR)对精制前后单体以及树脂的结构进行了表征、利用热分析仪(TG)和差式扫描量热仪(DSC)对树脂的热性能进行了分析,同时研究了精制时碱液浓度对树脂饱和吸油率、吸油速率以及充分溶胀后树脂剩余率的影响。结果表明,精制后单体合成的树脂耐热性能有了明显改善,热降解温度大大提高;精制前后单体合成的树脂,由于杂质存在的缘故,其低温玻璃化转变类型明显不同;经6wt%碱液和8wt%碱液精制后单体的纯度有了明显提高,由其合成的树脂饱和吸油率,吸油速率都有较大提高,甚至接近化学纯单体合成树脂的饱和吸油率。 相似文献
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有机膨润土改性高吸油树脂复合材料的合成及性质 总被引:1,自引:0,他引:1
以十六烷基三甲基溴化铵为表面改性剂制备了有机膨润土,并制备了以甲基丙烯酸十六酯为单体的吸油树脂/有机膨润土复合材料.采用X射线衍射仪(XRD)、傅里叶变换红外光谱仪(FTIR)、扫描电子显微镜(SEM)对样品进行分析.结果表明,经十六烷基三甲基溴化铵改性的膨润土层间距由原来的1.12 nm增大到1.87 nm;所得有机膨润土/吸油树脂复合材料对四氯化碳的饱和吸油率为16.3 g/g. 相似文献
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J. A. Hodgeson 《International journal of environmental analytical chemistry》2013,93(2):113-132
Abstract Instrumental and manual methods currently available for the measurement of atmospheric oxidants are surveyed. Techniques used in the United States are emphasized and their advantages and disadvantages are discussed. Commercial systems are evaluated in terms of general operating principles rather than of specific instruments. The ability of these techniques to meet the measurement requirements defined by U.S. Federal air quality oxidant criteria are discussed. Alternative chemical techniques that may have some advantages over the neutral, buffered KI procedure are discussed. Also some attractive, alternative instrumental procedures that are ozone-specific are presented. These systems are based on chemiluminescence and ultraviolet absorption photometry. Electrochemical and colorimetric methods for total oxidant measurements are compared. Finally, some data are presented on relationships of ozone and total oxidants. 相似文献
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钼、钨系过氧化物是非常重要的Sharpless烯烃环氧化催化剂,有着非常广泛的工业发展前景。本文综述了钼、钨系过氧化物的种类,结构,合成方法及催化活性,分析了各种钼、钨系过氧化物的特点以及在催化环氧化领域的发展现状。同时,本文还讨论了钼、钨系过氧化物催化烯烃环氧化反应的机理。评述了在催化环氧化领域中两种主要理论——Mimoun机理与Sharpless机理的争论焦点及发展现状,以及计算化学对两种理论中间过渡态的研究进展,并且重点分析了Sharpless机理的过渡态结构。此外,本文还综述了影响钼、钨系过氧化物催化剂反应活性的各种因素以及质子所产生的副反应。最后,本文对应用于催化环氧化领域的钼、钨系过氧化物未来的研究方向提出了建议。 相似文献
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《Physics and Chemistry of Liquids》2012,50(6):561-568
Measurements of densities, speeds of sound, excess volumes and viscosities of binary mixture of methyl tert-butyl ether with tetralin and decalin are reported at 303.15?K over the entire range of composition. Excess volumes are measured using batch dilatometer technique. Sound speeds are obtained using ultrasonic interferometer. Densities are computed from excess volume data. Isentropic compressibilities are derived from density and sound speed data. Speeds of sound are evaluated on the basis of Jacobson's free length theory and Schaff's collision factor theory. The predicted values are in good agreement with the experimental results. The viscosity data are analysed on the basis of corresponding states approach. Excess volumes and deviation in isentropic compressibilities are negative and deviation in viscosities are positive over the entire composition range. The experimental results are discussed in terms of possible molecular interactions between unlike molecules. 相似文献
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Barbara Pacholczyk-Sienicka Grzegorz Ciepielowski ukasz Albrecht 《Molecules (Basel, Switzerland)》2021,26(2)
Spices and herbs are among the most commonly adulterated food types. This is because spices are widely used to process food. Spices not only enhance the flavor and taste of food, but they are also sources of numerous bioactive compounds that are significantly beneficial for health. The healing effects of spices are connected with their antimicrobial, anti-inflammatory and carminative properties. However, regular consumption of adulterated spices may cause fatal damage to our system because adulterants in most cases are unhealthy. For that reason, the appropriate analytical methods are necessary for quality assurance and to ensure the authenticity of spices. Spectroscopic methods are gaining interest as they are fast, require little or no sample preparation, and provide rich structural information. This review provides an overview of the application of NMR spectroscopy combined with chemometric analysis to determine the quality and adulteration of spices. 相似文献
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《印度化学会志》2023,100(2):100871
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使用高灵敏的光腔衰荡光谱(CavityRingDownSpectroscopy)技术测出了异丙醇的O-H伸缩v=4、5振动泛频光谱,每个振动能级都有三个吸收峰,被归属为分子构像的O-H伸缩泛频吸收.给出了光腔衰荡光谱的振动泛频吸收的谱带强度公式,并求得分子不同构像在不同振动能级的O-H伸缩泛频吸收的谱带强度;同时利用局域模理论,求得分子各O-H伸缩局域模振子的机械频率(X1)、非谐性(X2)以及解离能(D).用密度泛函(DFT)B3LYP/6-31+G*理论方法优化了分子的各种可能构像,验证了分子存在反式(trans)和偏转(gauche)两种稳定构像,计算的分子的O-H伸缩频率及构像稳定性同实验结果是一致的. 相似文献
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Different methods for construction of contactless conductivity detectors (CCD) for microchip electrophoresis device are described in this review. This includes three main schemes of CCD for microchips, such as (i) the detection electrodes are placed along the microchannel from outside of the microchip and they are insulated from the channel by the cover lid of microchip device; (ii) the electrodes are placed across of the microchannel in the same plane and they are insulated by thin separation channel walls and (iii) electrodes are buried in widened part of microchannel and they are insulated from solution by ultrathin layer of silicon carbide. Specific issues related to the CCD on microfluidics are discussed, such as an influence of shape and magnitude of ac voltage and placement of electrodes and their insulation. Various applications for security, pharmacological, bioassays and food analysis purposes are described. 相似文献
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Pterins are bicyclic heterocycles that are found widely across Nature and are involved in a variety of biological functions. Notably, pterins are found at the core of molybdenum cofactor (Moco) containing enzymes in the molybdopterin (MPT) ligand that coordinates molybdenum and facilitates cofactor activity. Pterins are diverse and can be widely functionalized to tune their properties. Herein, the general methods of synthesis, redox and spectroscopic properties of pterin are discussed to provide more insight into pterin chemistry and their importance to biological systems. 相似文献
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Stretchable conductors are indispensable components of stretchable electronic devices, such as stretchable sensors, transistors, light-emitting diode arrays, solar cells, and so on. However, most of the conductive materials are stiff with very low stretchability. Nature has evolved various strategies to realize stretchability, which give a lot of inspirations to the design and fabrication of stretchable conductors. We herein summarized the nature’s strategies to realize stretchability and revealed the underlying mechanisms. After that, the applications of these strategies in fabricating stretchable conductors are exemplified and the effects of some important parameters on the performances are discussed. Then, possible applications of these stretchable conductors are summarized. Finally, critical issues in the stretchable conductors are discussed and several prospective exploration directions are provided. 相似文献