Poly(N-vinyl-2-pyrrolidone) hydrogel production by ultraviolet radiation: new methodologies to accelerate crosslinking

Poly(N-vinyl-2-pyrrolidone) hydrogels produced by high-energy radiation relies on water radiolysis as a primary process leading to crosslinks. Conversely, ultraviolet direct irradiation into PVP leads to crosslinking trough pyrrolidinone moiety photolysis. However, this process showed to be rather inefficient. This work describes the crosslinking of poly(N-vinyl-2-pyrrolidone) based on hydrogen peroxide photolysis, therefore mimicking water radiolysis, using UV-C (e.g. low pressure Hg lamp) or UV-A radiation sources. The process efficiency and the properties of the hydrogel formed are discussed and compared with other methods of hydrogel production.     

纳米TiO2复合铁钛防锈颜料的研制及产业化进展

介绍了纳米TiO2复合铁钛防锈颜料的制备原理、工艺、技术指标;描述了铁钛防锈涂料的配方、性能检验和产业化进展情况.     

4-氟-2-氯苯胺的合成研究

介绍了以 4 氟苯胺为原料 ,通过乙酰化、氯代、水解三步制备 4 氟 2 氯苯胺的方法 ,对主要的影响因素作了考察并得出结论 :乙酰化反应温度应小于 30℃ ;氯代中 2 /SO2 Cl2为 1∶0 9(mol/mol)时较好 ;在水解阶段盐酸浓度控制在 4mol/L较佳 ,4 氟 2 氯苯胺的纯度大于 99% ,总收率达到 70 %     

β-Sialon-Al2 O3-SiC系复相材料的研制和性能

研究了在 15 0 0℃的流动氮气中 ,用Al粉、Si粉、Al2 O3粉、刚玉和SiC的颗粒及细粉直接制备 β Sialon -Al2 O3-SiC系复相材料的氮化烧结技术。XRD和SEM分析表明 ,结合相 β Sialon的显微形貌随刚玉量的增加由纤维状向棱柱状转变 ,发育良好。复相材料的高温抗折强度高于常温抗折强度。抗热震试验结果显示 :添加适量的刚玉对β Sialon -SiC复相材料和添加适量的SiC对β Sialon -刚玉 复相材料都具有良好的增韧效果 ,这是β Sialon的纤维增强及柱状晶体原位自补强增韧和复合弥散相增韧综合作用的结果。抗碱和抗高炉渣试验均显示了该复相材料优良的抗碱和抗铁渣侵蚀能力。     

2-羟基-3-氰甲基-5-甲基苯乙酮的合成

探索黄酮醋酸类化合物中间体的合成方法。通过酰基化、Fries重排、氯甲基化和氰化合成2 -羟基 - 3-氰甲基 - 5 -甲基苯乙酮 ,获得了满意的收率 ( 88.5 % )。采用新方法合成了鲜见文献报道的新化合物 2 -羟基 - 3-氰甲基 - 5 -甲基苯乙酮。该方法具有反应时间短、操作简便、收率好等优点。     

Characterization and Catalytic Properties of Combustion Synthesized Au/CeO2 Catalyst

Ceria-supported Au catalyst has been synthesized by the solution combustion method for the first time and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Au is dispersed as Au⁰ as well as Au³⁺ states on CeO₂ surface of 20-30 nm crystallites. On heating the as-prepared 1% Au/CeO₂ in air, the concentration of Au³⁺ ions on CeO₂ increases at the expense of Au⁰. Catalytic activities for CO and hydrocarbon oxidation and NO reduction over the as-prepared and the heat-treated 1% Au/CeO₂ have been carried out using a temperature-programmed reaction technique in a packed bed tubular reactor. The results are compared with nano-sized Au metal particles dispersed on -Al₂O₂ substrate prepared by the same method. All the reactions over heat-treated Au/CeO₂ occur at lower temperature in comparison with the as-prepared Au/CeO₂ and Au/Al₂O₂. The rate of NO + CO reaction over as-prepared and heat-treated 1% Au/CeO₂ are 28.3 and 54.0 mol g^-1 s^-1 at 250 and 300 °C respectively. Activation energy (E _a) values are 106 and 90 kJ mol^-1 for CO + O₂ reaction respectively over as-prepared and heat-treated 1% Au/CeO₂ respectively.     

SO_4~(2-)TiO_2固体超酸催化合成异丙基萘的研究

用SO2 - 4 TiO2 固体超酸为催化剂合成了二异丙基萘 ,生产过程简单、无污染、无腐蚀。SO2 - 4 TiO2 固体超酸催化剂较为适宜的制备条件是 :浸酸浓度为 0 5 0mol/L、焙烧温度为 5 0 0℃。在催化剂用量为 10 %、反应温度为 160℃、反应时间为 2 5h的条件下连续两次使用SO2 - 4 TiO2 超酸催化萘对丙烯的烷基化反应 ,产品中一异丙基萘、二异丙基萘、三异丙基萘的总含量大于 98%。     

掺杂型尖晶石Li_(1.05)Mg_xMn_(2-x)O_4的合成及性能研究

采用高温固相法制备了尖晶石正极材料L iMxMn2-xO4(X=0.04,0.06,0.08,0.10),并用XRD、SEM、ICP-AES、充放电测试等手段研究了其组成、结构、表观形貌和电化学性能。结果表明:该法制备的尖晶石正极材料L iMxMn2-xO4为单一尖晶石结构,粒径分布均匀,其比容量和循环性能较未掺杂尖晶石L iMn2O4有显著的提高。     

2,6-二氟苯甲酸合成工艺研究

为优化2,6-二氟苯甲酸(DFBA)的合成工艺,以2,6-二氯苯腈(DCBN)和氟化钾为原料,N,N-二甲基酰胺(DMF)为溶剂,在聚醚类催化剂A的催化下氟代合成中间体2,6-二氟苯腈,然后中间体在碱性条件下水解制得(DFBA).试验结果表明,合成DFBN的最佳条件为:DCBN在DMF中的质量浓度为0.38g/mL,KF的量为DCBN的量的2.3～2.4倍,反应时间10 h,最高收率93.5%;合成DFBA时,以质量分数为20%的NaOH为介质,反应时间9 h,收率≥92%.收率93.5%,纯度99.7%.该工艺收率高、三废排放少,可节省成本,有望工业推广.     

SO2-4/La2O3-ZrO2催化合成亚油酸乙酯

将SO2-4/ZrO2负载镧制备了新型催化剂SO2-4/La2O3-ZrO2,以亚油酸和乙醇的酯化反应为探针,考察了不同制备条件对催化剂性能的影响,结果表明,La3+浸渍浓度为0.07 mol/L,经110℃烘干后于500℃焙烧3 h所得催化剂活性最好.采用正交实验法对影响酯化反应的因素进行考察,最佳实验条件为n(醇):n(酸)= 6:1,反应时间6 h,催化剂用量3%(亚油酸),酯化率可达93.7%.且该催化剂具有良好的重复使用和再生能力.