高岭土催化甲醇脱水制二甲醚的研究

比较研究了高岭土的结构特征,采用常压微型反应装置评价了高岭土作为催化甲醇制二甲醚催化剂的活性,并对高岭土进行了酸处理改性研究.结果表明,高岭土中高结晶度的高岭石有利于催化甲醇脱水制二甲醚,酸处理改性能提高高岭土的催化活性.     

Superabsorbent hydrogel composites

A new cost‐effective approach to enhance gel strength of superabsorbent hydrogels was invented. Superabsorbent hydrogel composites (SHCs) were prepared through an optimized rapid solution polymerization of concentrated partially neutralized acrylic acid in the presence of a crosslinking agent under normal atmospheric conditions. Kaolin was used as an inorganic component in the polymerization process to strengthen the hydrogel products. FT‐IR spectroscopy was used to confirm grafting of acrylic chains on to the surface of kaolin particles. Morphology of the products was studied by scanning electron microscopy (SEM). Compared with the kaolin‐free hydrogel (control), kaolin caused a reduced equilibrium swelling and swelling rate as low as 17–31% and 19–29%, respectively. Kaolin, however, resulted in enhanced gel strength as high as 21–35% compared to the control. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to study thermal properties of the composites. The SHCs exhibited higher thermal stability than the control. Meanwhile, changes in certain thermal transitions reconfirmed the chemical interaction of the acrylic chain with kaolin. These thermostabilized strengthened superabsorbent hydrogels may be considered as good candidates for agricultural application to retain more water under soil pressure. Copyright © 2003 John Wiley & Sons, Ltd.     

Surface modification of highly dispersed rubber fillers and pigments by titanate proadhesive and hydrophobic compounds

A method of modifying silicate and carbonate fillers with titanate coupling agents and proadhesive agents was worked out. The modification aimed at hydrophobization of filler surface by introduction to the surface of functional groups with chemical affinity to polymers. Optimum amounts of modifying substances and appropriate conditions for performing the modification process were established. The obtained fillers showed a high degree of hydrophobicity.The modified fillers were applied in rubber mixtures based on butadienestyrene or natural rubber, in polyurethanes, in PVC, and as pigments in oil dyes of high corossive resistance.     

永磁叶轮式除铁装置对煤系高岭土工业的影响

GCT-2型永磁叶轮式除铁装置的研制成功解决了高岭岩成分中含铁量过高的问题。促进了煤系高岭土工业的发展。文章简要介绍了该装置的结构、工作原理及其性能特点。     

Mechanical,Thermal and Morphological Behaviors of Castor Oil Based PU/PS Interpenetrating Polymer Network-Metakaolin Composites

The meta kaolin (MK) clay particulate filler with different weight ratios viz., 0, 5, 10, 20 and 30 wt% were incorporated into castable polyurethane (PU)/polystyrene (PS) (90/10) interpenetrating polymer network (IPN). The effects of MK particulate filler loading on the mechanical and thermal properties of PU/PS (90/10) IPN composites have been studied. From the tensile behavior, it was noticed that a significant improvement in tensile strength and tensile modulus as an increase in MK filler content. Thermogravimetric analysis (TGA) data reveals the marginal improvement in thermal stability after incorporation of MK filler. TGA studies of the IPN composites have been performed in order to establish the thermal stability and their mode of thermal degradation. It was found that degradation of all composites takes place in two steps. Degradation kinetic parameters were obtained for the composites using three mathematical models. Tensile fractured composite specimens were used to analyze the morphology of the composites by scanning electron microscopic (SEM) technique.     

Effect of Aging on the Synthesis of Kaolin-Based Zeolite Y from Ahoko Nigeria Using a Novel Metakaolinization Technique

Zeolite Y was systematically synthesized from Ahoko Nigerian kaolin in a conventional hydrothermal system using novel metakaolinization technique. The effect of aging on the formation of zeolite phase was investigated during the course of the synthesis. A rapidly processed metakaolin at a temperature of 600°C and exposure time of 50 minutes, which is capable of reducing the energy and cost of producing it was used to study the synthesis of zeolite Y. It was found that aging conditions play a prominent role in the preparation of zeolite Y from Ahoko metakaolin. Aging played a significant role by increasing the crystallinity of the final product even though zeolite Y was obtain without aging. The outcome of zeolite Y synthesized from Ahoko kaolin in 9 hours at 100°C was different from most reports on the synthesis of zeolite Y from kaolin where longing time (72 hours) of crystallization are reported.     

谷胱甘肽在高岭土修饰碳糊电极上的电化学研究

制备了高岭土修饰碳糊电极(KCPE),并以氢醌(HQ)为电催化介质测定还原型谷胱甘肽(GSH)。实验结果表明,在该电极上谷胱甘肽(GSH)的加入对氢醌的电化学响应有明显提高,且电催化氧化峰电流与GSH浓度呈良好的线性关系,由此可采用差分脉冲伏安法(DPV)对GSH进行定量测定。对修饰电极的电化学性能进行了表征,测得电极有效表面积为0.118 6 cm2、电荷传递系数为0.68、表观速率常数为1.08×104cm3·mol-1·s-1。在优化条件下,测得GSH在KCPE上的线性范围为0.1~1,2.5~25μmol/L,检出限为0.073μmol/L。用该方法对含GSH的市售药进行测定,结果满意。     

Novel filled polymer composites prepared from in situ polymerization via a colloidal approach: II. Blends of kaolin/Nylon-6 in situ composites with conventional Nylon-6 and -66

A novel in situ composite comprised of kaolin clay fillers and polyamide 6 (Nylon-6) was synthesized via a colloidal approach by suspending kaolin particles in aqueous caprolactam and then polymerizing the caprolactam under elevated temperature and pressure. This in situ polymerization technique enables the deposition of nylon molecules directly onto the filler surface. It offers a much larger contact surface area for the nylon molecules to interact with the filler particles and enhances filler/matrix interaction through polymer miscibility. The kaolin particles were shown to be uniformly dispersed in Nylon-6 matrix without appreciable agglomeration. In the highly clay-loaded composites such as the 50/50 kaolin/Nylon-6 in situ composite, the deposited nylon molecules probably form a coated layer on the filler particles. This kind of nylon coated fillers may be applied as a reinforcing entity to commercial Nylon-6 or −;66 by improving particle dispersion and melt processability. The 50/50 kaolin/Nylon-6 in situ composites have been used as a masterbatch for blending with commercial Nylon-6 and Nylon-66 to take advantage of their good properties and to reduce cost. Rheology and mechanical properties of the masterbatch/nylon composites have been investigated in comparison with those of the conventional melt-mixed composites. The improvement of rheological and mechanical properties of the in situ composites has been discussed in relation to the composite structure. © 1996 John Wiley & Sons, Inc.     

Novel filled polymer composites prepared from in situ polymerization via a colloidal approach: I. Kaolin/Nylon-6 in situ composites

A mineral-filled in situ composite was prepared by a colloidal approach by first suspending kaolin filler particles in aqueous caprolactam, and then polymerizing caprolactam in situ at high pressure and temperature. The purpose of this colloidal in situ polymerization is to improve particle dispersion and to enhance interaction of the filler to the polymer matrix. X-ray diffraction studies of the in situ kaolin/Nylon-6 composites revealed that the x-ray peak corresponding to the α-crystal form of Nylon-6 diminished with increasing kaolin loading, while the γ-crystal structure became more pronounced. The degree of crystallinity of Nylon-6 remained fairly unchanged with the kaolin loading level in the in situ composites. Calorimetric and dynamic mechanical studies exhibited that the glass transition temperature of the resulting composite increased significantly with increase in kaolin concentration, suggesting strong filler-matrix interaction at the kaolin/Nylon-6 interface. Scanning electron microscopic (SEM) results showed uniform filler dispersion in the in situ composites relative to the conventional melt-mixed composites. Modulus and tensile strength of these in situ composites were found to be distinctively higher than that of the conventional melt-mixed kaolin/Nylon-6 composites. However, as typical for composite materials, drawability and fracture toughness decreased with increasing kaolin loading. © 1996 John Wiley & Sons, Inc.     

甜菜碱OSB-12@高岭土杂化材料对染料吸附机理研究

实验设计以硅酸铝为实体框架、十二烷基乙氧基磺基甜菜碱(OSB-12)为功能有机物, 通过共沉淀法合成同时吸附阴、阳离子染料的纳米材料. 借助FT-IR, SEM以及比表面孔隙分析等多种手段表征该吸附材料的结构、形貌. 材料通过静电纺丝制备成微米纤维, 解决了材料的便捷、完全回收问题, 且对阴、阳离子染料均有良好吸附效果, 吸附速率快. 结果表明, 弱酸性桃红B和碱性艳蓝BO吸附量分别达到471和847 mg/g, 论文详细讨论了染料的吸附机理, 电荷作用在离子型染料吸附过程中起主导作用, 即包埋在材料中的两性表面活性剂OSB-12发挥着离子交换的功能. 从染料去除率和材料分离性能等可以预见, 该材料在实际染料废水处理中体现了良好的应用潜力.