Preparation and properties of natural rubber latex-g-modified cationic polyacrylamide copolymers and its palm oil absorbent

Abstract

The grafting of a modified cationic polyacrylamide (MCPAM) onto natural rubber (NR) latex to form a copolymer using potassium persulphate (K₂S₂O₈) to generate active radicals on both the NR particle surface as well as on the MCPAM molecules was confirmed by ATR-FTIR. The copolymers showed a marked ability to absorbe palm oil up to 10 g g^?1. First, the high molecular weight cationic polyacrylamide (CPAM) was reduced by using a combination of K₂S₂O₈ and hydrogen peroxide (H₂O₂) through thermal degradation. The molecular weight of the CPAM as determined by viscosity was about 4000 g mol^?1. It was then added to the NR latex in the presence of Terric16A16 at 60°C for 3 h and cast as a film on a glass plate to obtain the NR-g-PAM. In a water medium, the swelling ratio of the modified NR decreased as a function of the CPAM concentration. Also the thermal stability of the modified NR-g-PAM was higher than of the NR/PAM blend as confirmed by TGA. Finally, the ability of NR-g-MCPAM to absorb palm oil was investigated.     

Group Contribution Concept for Computer‐Aided Design of Working Fluids for Refrigeration Machines

The operation and performance of any refrigeration system depends mainly on the choice of the working fluids. Since classical compounds like the chlorofluorocarbons and hydrochlorofluorocarbons are now completely phased out, substitutes are required. In previous works, a method for computer‐aided design and test of alternative compounds were presented. Relevance and importance of the group contribution concept for such methods are investigated, considering two model systems, namely, the ejecto‐compression and absorption refrigeration machines with specific configurations like insertion of a distillation column and elimination of the condenser, respectively. The obtained results allow extending this approach to model other complex refrigeration systems.     

抗紫外线纤维及纺织品

抗紫外线纺织品的加工技术一是在纺丝过程中加入屏蔽剂,二是采用织物表面涂层法。介绍了常用的抗紫外线屏蔽剂和吸收剂,对国产抗紫外线涤纶长丝的物理指标及其织品的抗紫外效果进行了测试分析。结果表明抗紫外线纤维制成的纺织品具有较好的抗紫外线功能。     

甘蔗渣的几种高值化利用研究进展

甘蔗渣是糖厂重要的副产物之一,也是一种重要的可再生资源,本文主要综述甘蔗渣的几种高值化利用新途径,并提出了甘蔗渣高值化利用的发展方向。     

吸波涂料概述

重点对吸波涂料的吸波机理以及粘结剂和吸收剂种类进行了论述,并对吸波涂料的发展趋势进行了简单描述.     

Granulation of Fe-Al-Ce nano-adsorbent for fluoride removal from drinking water by spray coating on sand in a fluidized bed

A technology for the granulation of Fe-Al-Ce nano-adsorbent (Fe-Al-Ce) in a fluidized bed was developed. The coating reagent, a mixture of Fe-Al-Ce and a polymer latex, was sprayed onto sand in a fluidized bed. The granule morphology, coating layer thickness, granule stability in water and adsorption capacity for fluoride was investigated by analyzing samples for different coating time. The coating amount was from 3% to 36%. With increasing coating amount, granule stability decreased and adsorption capacity increased. FTIR analysis showed that the latex can react with active hydroxyl on the Fe-Al-Ce adsorbent, which led to a decrease of the adsorption capacity. Coated granules with a coating amount of 27.5% had a fluoride adsorption capacity of 2.22 mg/g (coated granules) at pH 7 and initial fluoride concentration of 0.001 M. A column test showed that 300 bed volumes can be treated with the effluent under 1.0 mg/L at an initial fluoride concentration of 5.5 mg/L, space velocity of 5 h^− 1 and pH of 5.8. The coating granulation of the Fe-Al-Ce adsorbent can produce granules that can be used in a packed bed for the removal of fluoride from drinking water.     

阻聚剂TBC对亚硫酸盐自动氧化的阻滞作用

通过除氧试验和空气氧化试验,研究了阻聚剂ＴＢＣ对亚硫酸盐自动氧化的阻滞作用。结果表明,自由基链反应引发剂铜离子能够加速亚硫酸盐与氧的反应,自由基吸收剂阻聚剂ＴＢＣ能够通过消除亚硫酸盐氧化过程中生成的自由基而抑制反应,水的ｐＨ值、碱度和硬度成分则无影响。试验结果为亚硫酸盐氧化的自由基机理提供了有力的证据,也为亚硫酸盐的贮存失效提供了有效的防止方法     

SF6气体绝缘金属封闭开关设备中吸附剂的设计用量

介绍了GIS设备内部水分的含量、灭弧单元电弧分解物的多少,吸收水分和电弧分解物所需吸附剂量的大小。     

常压下吸附─流化床冷冻干燥的研究

从冷冻干燥的基本原理入手,描述了常压吸附一流化冷冻干燥,并对其数学模型、实验装置提出具体的阐述,与真空冷冻干燥进行比较,认为常压下的冷冻干燥技术具有广阔的发展前景,值得进行深入的研究和探讨     

微孔淀粉的制备性质及应用

微孔淀粉是用具有生淀粉酶活力的酶在低于淀粉糊化温度下水解生淀粉形成的一种新型变性淀粉。微孔淀粉经交联、表面活性处理后，能改善其机械性能和表面性质。目前微孔淀粉主要用作微胶囊芯材、吸附剂和脂肪替代物等。