新的聚合物支载硼氢负离子还原剂系统研究 3: 聚合物支载还原剂III

硼氢化钠的低分子还原系统研究很多,但其聚合物支载还原剂相对来说就很少,而且仅以强碱型阴离子交换树脂来制备的聚合物试剂。为了寻找用途更广泛的、新的聚合物支载还原剂,我们进行了硼氢负离子的聚合物还原系统的研究;发现能用弱酸型阳离子交换树脂制备出新的聚合物支载还原剂。前文报道了用NaBH_4的水溶液和阴离子交换树脂     

离子交换-双氧水氧化法制备纳米CeO2晶体

以99.995% Ce(NO₃)₃和强碱性阴离子交换树脂为原料，采用离子交换-双氧水氧化法合成制备出纳米CeO₂晶体。并就离子交换反应中的Ce³⁺浓度、树脂加入速度和离子交换温度及H₂O₂加入速度等条件对CeO₂粒径的影响进行了探讨，得出了离子交换-双氧水氧化法制备纳米CeO₂晶体的最佳工艺条件。FTIR、TEM分析表明，离子交换法无需对合成的Ce(OH)₃溶胶进行洗涤即可去除NO₃^-、CO₃^2-等阴离子杂质，并用H₂O₂将该溶胶氧化，经真空干燥可制得粒径分布均匀，平均晶粒尺寸约3 nm，高纯度的CeO₂粉体。     

Structure formation in heavy metal oxyhydrates at low rates of gel formation

Oxyhydrate gels have a hydrophilic surface, due to which they undergo destruction and secondary polymerization in aqueous media. Prolonged storage in aqueous solution gives rise to regions with selfsimilar helical ordering in gels. Structuring of this kind is also observed when synthesis is conducted under conditions that provide low gelation rates. Electromagnetic UV and visible radiation is another means to change the gel structure; it makes the oligomer species pass into the excited state, due to which one of the directions of structuring becomes dominant. This work summarizes the results of computer simulation of gel agglomerates. For oxyhydrate systems, helical ordering was found to be one of the local energy minima. The units of a macrohelix can lie at various angles relative to one another, and they can change, after absorption of energy, the helix pitch and the order of elements in the helix.     

Water absorption of a diglycidyl ether of bisphenol A/1,3-bisaminomethylcyclohexane (DGEBA/1,3-BAC) epoxy resin system

The diffusive and dynamic mechanical behavior of the DGEBA/1,3-BAC epoxy resin system was studied during water absorption. The diffusion of water was investigated at 100% relative humidity, by immersion of specimens in water at 60, 80 and 100°C. In all absorption experiments, water diffusion followed Fick's law. Diffusion coefficients and saturated water concentrations are given for these temperatures. The activation energy for diffusion was determined from the relationship between the diffusion coefficient and the reciprocal of the absolute temperature. The value obtained was 31.2 kJ mol^–1. Dynamic mechanical analysis of samples immersed in 100°C water and with various water contents showed both a shift of T_g, defined by thetan peak, to lower temperatures and a slight decrease in the dynamic modulus in the presence of water. These effects are probably a result of plasticization.This work was supported by the Xunta de Galicia through grant XUGA-17201A92.     

后交联型St-DVB大孔吸附树脂对低级醇类的吸附性能研究

分别在静态和动态条件下研究了Friedel—Crafs后交联型聚苯乙烯-二乙烯基苯(St-DVB)大孔吸附树脂对水溶液中多种低级一元醇的吸附性能，测定静态吸附等温线和动态吸附曲线，并分别按照Langmuir和Freundlich模型进行拟合．结果显示，树脂对水中低浓度低级一元醇的吸附过程属于放热的物理吸附过程，树脂吸附能力随着一元醇碳原子数的增加，即分子内疏水基团质量的增加而增加；树脂对直链醇的吸附能力稍强于同分异构的支链醇．     

Investigation of the tensile properties of “epoxy resin‐monomer” systems using cationic UV‐crosslinkable blends

The compatibility of cycloaliphatic and aromatic multifunctional epoxides with several epoxide resins allows the development of a wide range of cationic radiation‐curable formulations. The influence of different “epoxide resin‐monomer” systems UV‐cured in the presence of suitable cationic photoinitiators on the resulting physicochemical film properties was studied, and the results are stated. Copyright © 2004 John Wiley & Sons, Ltd.     

High-temperature TG/DSC/QMS applications in environmental protection

The decomposition reactions of polystyrene, phenolic resin and a protective undercoating material for automobiles which contains PVC were tested using a new type of thermal analysis — mass spectrometry coupling system for measurements to 1500C or 2000C, which is based on the principle of a two-step skimmer orifice system. The results will be presented, with particular emphasis on the detection sensitivity of the new system for the products of decomposition.The capability of this coupling system to detect even heavy metals such as lead and silver in the waste gases from decomposition or after evaporation at high temperatures will also be demonstrated.     

大孔树脂吸附法处理含苯肼工业废水的研究

以Hz-841大孔树脂为吸附剂,95%乙醇为脱附剂处理含苯肼4000~5000mg/L的工业废水,取得了理想的分离效果,苯肼吸附率>99.8%,树脂工作吸附量40~50g/L。     

以硫醚为主链的螯合树脂研究Ⅰ.4-氨基安替吡啉树脂和乙基原磺酸基树脂的合成及吸附性能

聚环硫氯丙烷或环硫氯丙烷与环氧氯丙烷共聚物，在少量二乙烯三胺存在下制得交联预聚物，将交联预聚物与4－氨基安替吡啉（4AAP）或乙基原磺酸钾（PEA）反应，制得四种侧链带氨基安替吡啉，乙基原碘酸基的新型螯合树脂。它们对贵金属具有优良的吸附性能和高的吸附选择性。并通过X－射线光电子能谱初步探讨了树脂对金属离子的螯合作用。     

锂辉石—石灰石烧结中煤粉代替重油作燃料的研究和实践

目前世界锂工业原料以锂辉石为主。我国锂辉石储量居世界首位，主要分布于新疆、四川、湖南等地，其中又以四川的储量占全国第一。锂的主要基础化合物ＬｉＯＨＨ２Ｏ系用锂辉石－石灰石烧结法而得，烧结燃料是影响ＬｉＯＨＨ２Ｏ产品价格的重要因素之一。过去国内外均采用...