二苯基甲烷二异氰酸酯生产技术及发展

综述了二苯基甲烷二异氰酸酯(MDI)光气法生产中在连续缩合、MDI提纯和降低产品色度等方面的研究;MDI非光气法生产中合成苯氨基甲酸甲酯(MPC)所用催化剂,合成亚甲基二苯基氨基甲酸甲酯(MDU)所用催化剂、甲基化试剂和溶剂,MDU热分解或催化分解制备MDI所用催化剂和溶剂等方面的研究。光气法生产工艺存在固有的缺点,氨基甲酸酯分解法的非光气法生产工艺是MDI生产的研究新热点。     

89─Ⅰ型贮液式电化学气体传感器

报道的气体传感器是一种贮液式电化学气体检测池，选择不同的电极和电解质溶液就可制成多种不同气体的传感器。文中具体介绍了传感器的制作方法和用于光气检测的简单情况。     

三光气的合成及应用研究

以碳酸二甲酯为原料,合成一种使用安全、方便的光气代用品,使其具有与光气相同的反应活性,可代替光气完成相应的化学品的合成。     

光气合成反应器动态仿真

该文对光气合成管式反应器的动态仿真技术进行了研究.根据物料及焓守恒方程建立了管式反应器的动态机理模型,并根据模型的形式和特点选择了适当的数值计算方法,开发了光气反应器的动态模拟程序模块.模块应用结果表明,达到稳态时的结果能比较真实地反映生产实际情况,动态过程能很好地反映生产的变化趋势,并能完成对非正常工况的模拟.该模型对光气合成反应器动态特性和控制方式的研究以及光气合成相关工艺仿真培训系统软件的开发等都有重要的意义.     

Investigating ozone-induced decomposition of surface-bound permethrin for conditions in aircraft cabins

Abstract  The reaction of ozone with permethrin can potentially form phosgene. Published evidence on ozone levels and permethrin surface concentrations in aircraft cabins indicated that significant phosgene formation might occur in this setting. A derivatization technique was developed to detect phosgene with a lower limit of detection of 2 ppb. Chamber experiments were conducted with permethrin-coated materials (glass, carpet, seat fabric, and plastic) exposed to ozone under cabin-relevant conditions (150 ppb O₃, 4.5/h air exchange rate, <1% relative humidity, 1700 ng/cm² of permethrin). Phosgene was not detected in these experiments. Reaction of ozone with permethrin appears to be hindered by the electron-withdrawing chlorine atoms adjacent to the double bond in permethrin. Experimental results indicate that the upper limit on the reaction probability of ozone with surface-bound permethrin is ∼10⁻⁷. Extrapolation by means of material-balance modeling indicates that the upper limit on the phosgene level in aircraft cabins resulting from this chemistry is ∼1 μg/m³ or ∼0.3 ppb. It was thus determined that phosgene formation, if it occurs in aircraft cabins, is not likely to exceed relevant, health-based phosgene exposure guidelines.  

Practical Implications

Phosgene formation from ozone-initiated oxidation of permethrin in the aircraft cabin environment, if it occurs, is estimated to generate levels below the California Office of Environmental Health Hazard Assessment acute reference exposure level of 4 μg/m³ or ∼1 ppb.     

Temperature enhanced gas sensing properties of diamond films

Nanocrystalline diamond (NCD) film was used as a functional part of gas sensor. The gas sensing properties of H-terminated nanocrystalline diamond films were examined to oxidizing gases (i.e., COCl₂ and humid air). Pronounced increase in the surface conductivity (3 orders of magnitude) was found after sensor exposure to phosgene gas and was explained by the surface transfer doping effect. We also present a possible way how to achieve sensor selectivity, i.e. how to distinguish between phosgene and humid air (the mostly present background gas in a common environment).     

Cl2 Adsorption and Desorption over Ordered Mesoporous Carbon Materials as an Indicator for Catalytic Phosgene Formation

The presented work evaluates the implementation of adsorption and desorption experiments with Cl₂ over carbon materials towards the development of more active and stable catalysts for industrial phosgene synthesis. By using a soft templating method as a tool, ordered mesoporous carbon materials with tunable porosity, surface area, and degree of graphitization were synthesized and utilized as model system. The Cl₂ adsorption/desorption properties of these materials were studied and compared to commercial activated carbon. To draw correlations between Cl₂ adsorption/desorption behavior and catalytic performance, the materials were further tested in the phosgene formation in a plug flow reactor. However, the chemical reaction of Cl₂ with carbon during the adsorption/desorption experiment hinders a direct correlation.     

碳酸二乙酯合成方法综述

首先介绍了碳酸二乙酯的性质和用途，然后对各种生产方法进行综述，通过分析得出了以绿色化工产品碳酸二甲酯为原料与乙醇酯交换工艺是清洁生产方法的结论。     

对硝基异氰酸苯酯的制备

介绍用光气和对硝基苯胺在乙酸乙酯溶剂中反应来制备对硝基异氰酸苯酯的方法，并讨论了其最佳工艺条件。     

光气检测用小分子荧光探针的研究进展

光气因其剧毒性对社会公共安全和人类健康造成巨大威胁，对其实时监测、检测十分必要。荧光探针由于选择性好、灵敏度高、可实时监测、成本低、操作简单等优点已成为识别光气分子的有力工具。首先，综述了光气小分子荧光探针的研究进展；然后，以荧光分子的识别基团为分类标准，从设计思路和识别机理对各类荧光探针进行了系统的归纳和总结；最后，对光气小分子荧光探针进一步的发展方向及其所面临的挑战进行了展望。