水溶性改性纤维素对粘土水化的抑制作用

为探索水溶性改性纤维素聚合物作为钻井用页岩水化抑制剂的可能性，本文以工业棉纤维为基本原料，在会成条件相当的情况下制备了羧甲基纤维素钠（CMC－Na）、羧甲基纤维素钾（CMC－K）、阳离子化羧甲基纤维素钠（CCMC－Na）与阳离子化波甲基纤维素钾（CCMC－K）四种结构不同的水溶性改性纤维素聚合物；以X-射线衍射、膨胀性试验及造浆试验考察了它们对粘土水化的抑制作用和机理。研究表明，在本试验条件下，四种改性纤维素聚合物对粘土水化均有一定的抑制效果；而合成时引入钾离子或季接阳离子则可使产物的抑制能力明显增强．     

四种不同产地无烟煤性能研究

对四种国产无烟煤的化学成分、氧化率和岩相结果进行了分析，以及用此四种无烟煤在相同工艺条件下制成的微孔炭砖试样进行了试验研究。结果表明，阳泉煤制成的微孔炭砖性能优良，且阳泉煤变质程度最好，是生产微孔炭砖最为理想的原料；宁夏太西煤只要控制好煅烧质量，也是生产微孔炭砖的优质原料。     

镁铝阴离子粘土对砷酸根离子的吸附作用

利用共沉淀水热法制备了镁铝阴离子粘土材料，研究了其水溶液对砷酸根离子的去除能力。结果表明：镁铝阴离子粘土对砷酸根离子具有较高的去除率和吸附容量、较快的吸附速度。砷酸根离子的吸附平衡数据很好的符合Freundlich型吸附等温方程。同时，吸附动力学数据完全符合Lagergren二级速度方程。吸附砷酸根离子后的阴离子粘土材料，用稀NazCO3溶液可以很好的洗脱再生。阴离子粘土对砷酸根离子的吸附属于层间离子交换作用。     

聚酰胺6/黏土/聚乙二醇共混调温纤维的制备与性能

通过熔融纺丝法制备了系列聚酰胺6/黏土/聚乙二醇(PTFs)共混调温纤维,并采用傅里叶红外光谱仪、差示扫描量热仪、热红外成像仪、热失重分析仪和复丝强力仪测试了纤维的结构、热性能、调温性能和力学性能。研究显示,PTFs调温纤维的结晶温度为33℃,结晶焓值达到8.46 J/g,且在100次升降温热循环后调温纤维仍保持良好的热性能。通过模拟冷热环境交替下纤维的温度—时间响应行为发现,在热环境(90℃)和冷环境(10℃)下,调温纤维体现出明显的温度滞后响应,与纯PA6纤维相比温差达到3℃。黏土/聚乙二醇在纤维中的最大质量分数为15%,在牵伸4倍时,纤维的拉伸断裂强度达到3.15 cN/dtex。     

Preparation and characterization of polystyrene–clay nanocomposites by free‐radical polymerization

The polymerizable cationic surfactant, vinylbenzyldimethylethanolammouium chloride (VBDEAC), was synthesized to functionalize montmorillonite (MMT) clay and used to prepare exfoliated polystyrene–clay nanocomposites. The organophilic MMT was prepared by Na⁺ exchanged montmorillonite and ammonium cations of the VBDEAC in an aqueous medium. Polystyrene–clay nanocomposites were prepared by free‐radical polymerization of the styrene containing intercalated organophilic MMT. Dispersion of the intercalated montmorillonite in the polystyrene matrix determined by X‐ray diffraction reveals that the basal spacing is higher than 17.6 nm. These nanocomposites were characterized by differential scanning calorimetry (DSC), transmission electron micrograph (TEM), thermal gravimetric analysis (TGA), and mechanical properties. The exfoliated nanocomposites have higher thermal stability and better mechanical properties than the pure polystyrene. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1370–1377, 2002     

The effects of air content on permeability of lightweight concrete

Air entraining agent is used to control the floatation of lightweight aggregate (LWA) in lightweight aggregate concrete (LWAC), therefore reducing the segregation of LWAC. At the same time, using an air entraining agent will affect the water sorption of the concrete. In this paper, two lightweight concrete mixes of density 1000 kg/m³ and air content of 13.5% and 31.9% were compared and the effects of entrained air on the strength, surface sorptivity, and chloride permeability of LWAC are presented. Results show that the use of porous LWA would not lower the permeability resistance of concrete. Entrained air had little effect on sorptivity but a major effect on chloride permeability. The weaker pores' network in the cement paste is the basic cause for the high chloride permeability of concrete than the use of porous LWA. Although chloride permeability of low density LWAC concrete decreased with age of concrete, it was found that the concrete was not dense enough to stop the chloride ion to penetrate through the concrete before the concrete mature at 90 days.     

Influence of Synthesis Conditions and Cerium Incorporation on the Properties of Zr-Pillared Clays

Zr-pillared clays were prepared from ZrOCl₂ pillaring solutions by adopting different preparative conditions. Ce³⁺ ions are introduced to Zr-pillared clays by co-intercalation method. The resulting samples were characterized by XRD, TGA, N₂ sorption and UV-VIS-Diffuse reflectance spectroscopy techniques. Basal spacings in the range of 18–21 Å were observed depending upon the preparative condition. TG analysis shows three weight loss regions corresponding to removal of various types of water molecules. All pillared clays show Type-I sorption isotherm typical of microporous materials. Pillaring under refluxing condition is found to have beneficial effect on the surface area and pore volume of the Zr-pillared clay. The chemical environment and location of Ce³⁺ ions is studied by UV-VIS-DRS. The Ce³⁺ ions are found to be present in the micropores of the Zr-pillared clays. However heat treatment at higher temperature may result in peripheral interaction between Ce³⁺ ions and Zr-pillars. Catalytic activity of these pillared clays was evaluated for cyclohexanol dehydration which correlates well with the Brønsted acidity of these materials. The Zr-Pillared clay containing Ce³⁺ ions show good catalytic activity and stability with reaction time which has been ascribed to the stabilazition of the Brønsted acidic centers.     

Polypropylene–clay blends compatibilized with MAH‐g‐POE

A series of new Polypropylene (PP)–clay blends, containing 5 wt % clay, were prepared by melt compounding with maleic anhydride grafted poly(ethylene‐co‐octene) (MAH‐g‐POE) as the compatibilizer by varying its content from 0 to 20 wt %. The effect of MAH‐g‐POE on the PP–clay miscibility was examined by X‐ray diffraction (XRD), scanning electronic microscope (SEM) observation, differential scanning calorimeter (DSC) analysis, dynamic mechanical thermal analysis (DMTA), and rheological testing in sequence. The results showed that the addition of MAH‐g‐POE could improve the dispersion of clay layers in PP matrix and promoted the interaction between PP molecules and clay layers. At 10 wt % MAH‐g‐POE, the PP–clay blend exhibited a highest value of Tc,onset and Tg as well as a biggest melt storage modulus (G′), indicating the greatest PP–clay interaction. On the other hand, improved toughness and stiffness coexisted in blends with 5–10 wt % loading of MAH‐g‐POE. In view of SEM and DMTA observations, MAH‐g‐POE was well miscible with the PP matrix, even with the concentration up to 20 wt %. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 2558–2564, 2006     

Preparation and barrier property of poly(ethylene terephthalate)/clay nanocomposite using clay‐supported catalyst

Poly(ethylene terephthalate) (PET)/clay nanocomposite was prepared by the direct polymerization with clay‐supported catalyst. The reaction degree of catalyst against the cation exchange capacity of clay was 8 wt %. The intercalation of PET chains into the silicate layers was revealed by X‐ray diffraction studies. SEM morphology of the nanocomposite showed a good dispersion of clay‐supported catalyst, ranging from 30 to 100 nm. The intercalated and exfoliated clay‐supported catalyst in PET matrix was also observed by TEM. The improvement of O₂ permeability for PET/clay‐supported catalyst composite films over the pure PET is approximately factors of 11.3–15.6. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4875–4879, 2006     

炼铜转炉用镁铬砖损毁机理的探讨

研究了炼铜转炉用直接结合镁铬、硅酸盐结合镁铬砖的损毁机理。结果表明：对直接结合镁铬砖而言，不论是其抗冰铜的渗透性、抗转炉渣的侵蚀性，还是热震稳定性、高温强度均优于硅酸盐结合镁铬砖。所以使用直接结合镁铬耐火材料替代硅酸盐结合镁铬耐火材料可以大幅度地提高转炉炉龄。