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.     

Pt/C活性催化剂催化氢化合成6-氯-2-羟基喹喔啉

以对氯邻硝基乙酰乙酰苯胺为原料，在碱性条件下经环合及催化氢化合成6-氯-2-羟基喹喔啉。采用自制的Pt／C催化剂，考察了反应条件对产品收率的影响，在85℃，1．0～1．3MPa氢气压力下进行加氢还原反应，总收率89．6％(以对氯邻硝基乙酰乙酰苯胺转化为6-氯-2-羟基喹喔啉)。     

碳铵化肥发青问题解决小结

探讨了该厂化肥生产中碳铵发青的原因,通过硫化氢含量的测定,分析了系统内外影响因素,提出了解决措施,达到了不停车稳定产品质量的目的。     

Olefins polymerization on titania and titania-supported rhodium

The adsorption of ethene and propene on titania and titania-supported rhodium has been studied, observing a continuous adsorption even after 24 h. The samples have been reduced at 623 or 773 K, but no difference was observed, whichever the reduction temperature or the presence of rhodium, on the amount of gas adsorbed per unit of surface area of the solid. A study of the polymerization has been done following the equal reactivity hypothesis, and it has been concluded that the role played by the rhodium particles is to facilitate adsorption of the gaseous molecule, that is then transfered to the surface of the support, where it polymerizes.     

Kinetics of the methanation of carbon dioxide over a supported Ni-La2O3 catalyst

The kinetics of the methanation of carbon dioxide was investigated using an alumina supported Ni-La₂O₂ catalyst in a differential and integral reactor. In the differential reactor the molar ratio of H₂ to CO₂ was varied from 0.6 to 30. In the integral reactor the rates were measured with up to 90% conversion. Both reactor tests were carried out at temperatures between 513 and 593 K. The experimental results were described by a Langmuir-Hinshelwood type equation. The kinetics can be explained by assuming equilibrium of dissociative carbon dioxide and hydrogen adsorption, and assuming hydrogenation of surface carbon as the rate determining step.     

IR study of the interaction of hydroxyl groups of silica gel with Cr species of Phillips' type catalysts

Spectroscopic evidence for the interaction of hydroxyl groups and chromium ions was obtained using a catalyst prepared from chromyl chloride. A new OH peak, observed at 3705 cm^–1 after pumping away CO gas, is attributed to the direct interaction of OH with the low-valent chromium. This peak shifts to 3590 cm^–1 on contact with O₂ at room temperature and it is assigned to a hydroxyl interacting with the oxidized chromium. New assignments are also proposed for IR bands of CO presorbed on the catalyst. The peak due to CO at 2188 cm^–1 decreases as the OH intensity at 3705 cm^–1 increases, suggesting that the former peak arises from adsorption on Cr(II) species to which two oxygen atoms are attached.     

2,6-二乙酰基吡啶合成方法的改进

优化了2，6—二乙酰基吡啶的合成工艺。以2，6—吡啶二羧酸为原料，经过醇化及克莱森酯缩合反应，合成了2，6—二乙酰基吡啶，2，6—吡啶二羧酸二乙醇和2，6—二乙酰基吡啶的分离收率分别为94．1％和88．9％，2，6—二乙酰基毗啶的质量分数大于99％。     

甲基葡萄糖甙（MeG）水溶液工艺改进试验

介绍了用５次以上的母液生产ＭｅＧ水溶液工艺的改进试验。