离子选择电极法测定陶瓷工业废水的含氟量

本文采用氟离子选择电极法,该法具有测定简便、快速、灵敏、选择性好、可测定浑浊、有色样品等优点,最低检出浓度为0.05mg/L,适用浓度范围宽,在测定含陶瓷工业废水氟量中取得良好效果。     

高性能含氟丙烯酸涂料的研制

将液态含氟丙烯酸单体与丙烯酸酯类单体采用常压溶液聚合工艺，合成了支链含氟的丙烯酸树脂。配成白色磁漆后，机械性能、耐介质性能及耐候性与其他含氟树脂所制磁漆相当。     

Synthesis of Exocyclic Trisubstituted Alkenes via Nickel‐ Catalyzed Kumada‐Type Cross‐Coupling Reaction of gem‐ Difluoroalkenes with Di‐Grignard Reagents

A practical, nickel‐catalyzed Kumada‐type double cross‐coupling reaction of gem‐difluoroalkenes with 1,4‐ or 1,5‐di‐Grignard reagents was developed. The reaction proceeded efficiently at room temperature and a variety of cyclization products, arylmethylenecyclopentanes and arylmethylenecyclohexanes, were obtained in high to excellent yields, respectively.

     

Volatilization of fluorine in a CaO–SiO2–CaF2-based system with the substitution of Na2O with K2O

Cuspidine-based systems are used to control the crystallization in mold fluxes, which is enabled by CaF₂ additions. However, excess CaF₂ increases the corrosion of casting machines. Therefore, Na₂O and K₂O are added to the mold flux system to ensure an optimized crystallization and lubrication ability of the flux with the CaF₂ content. This study investigated the effect of substituting Na₂O with K₂O on the volatilization of fluorine in a CaO–SiO₂–CaF₂-based slag system at high temperatures. The substitution of Na₂O with K₂O was performed at 5 mol% intervals. The volatilization was observed by thermogravimetric analysis under several isothermal conditions. The mass loss was measured at a heating rate of 5, 10, and 20 K/min. As the temperature increased, the volatilization of the mixed samples increased. The activation energy was calculated using the Flynn–Wall–Ozawa and Kissinger–Akahira–Sunose methods. A kinetic analysis of the volatilization of fluorine was conducted using the calculated parameters and several known kinetic models. Consequently, the volatilization of the Na-rich sample was controlled by chemical reactions and that of the K-rich sample was identified to be controlled by a phase-boundary-controlled reaction. These results suggest that the addition of mixed alkali oxide promote the volatilization during the early stages of the reaction. From the post-experimental composition analyses, the remaining Na and K in the samples suggested a different mechanism for the Na and K volatilization. The volatilization of Na increased with time, whereas K volatilized easily during the beginning of the reaction.     

Activity of Fluorine‐Containing Analogues of WC‐9 and Structurally Related Analogues against Two Intracellular Parasites: Trypanosoma cruzi and Toxoplasma gondii

Two obligate intracellular parasites, Trypanosoma cruzi, the agent of Chagas disease, and Toxoplasma gondii, an agent of toxoplasmosis, upregulate the mevalonate pathway of their host cells upon infection, which suggests that this host pathway could be a potential drug target. In this work, a number of compounds structurally related to WC‐9 (4‐phenoxyphenoxyethyl thiocyanate), a known squalene synthase inhibitor, were designed, synthesized, and evaluated for their effect on T. cruzi and T. gondii growth in tissue culture cells. Two fluorine‐containing derivatives, the 3‐(3‐fluorophenoxy)‐ and 3‐(4‐fluorophenoxy)phenoxyethyl thiocyanates, exhibited half‐maximal effective concentration (EC₅₀) values of 1.6 and 4.9 μm , respectively, against tachyzoites of T. gondii, whereas they showed similar potency to WC‐9 against intracellular T. cruzi (EC₅₀ values of 5.4 and 5.7 μm , respectively). In addition, 2‐[3‐ (phenoxy)phenoxyethylthio]ethyl‐1,1‐bisphosphonate, which is a hybrid inhibitor containing 3‐phenoxyphenoxy and bisphosphonate groups, has activity against T. gondii proliferation at sub‐micromolar levels (EC₅₀=0.7 μm ), which suggests a combined inhibitory effect of the two functional groups.     

水性双组分氟丙烯酸—聚氨酯涂料的研制及性能测试

介绍了水性双组分氟丙烯酸-聚氨酯涂料所用原料及其预处理,水性双组分氟丙烯酸-聚氨酯涂料的羟基组分采用两步法合成:第一步合成了具有大分子表面活性剂性能的水性聚氨酯,在合成的过程中引入了双键和羟基组分;然后采用无皂乳液聚合的方法合成了以氟丙烯酸酯为核、聚氨酯为壳的水性树脂。并列举了采用该树脂与水性固化剂配合研制的清漆的性能指标,该清漆有着非常广泛的用途,讨论了影响涂料性能的各种因素。该双组分清漆水性含氟丙烯酸酯-聚氨酯清漆具有优异的综合性能。     

软化剂对F246氟橡胶性能的影响

研究了氟硅油、固体古马隆、齐聚酯对F246氟橡胶硫化胶硫化特性、力学性能、耐溶剂性能、耐热老化性能以及耐油性能的影响。研究结果表明,加入软化剂会降低混炼胶的最低和最高转矩;添加了氟硅油和齐聚酯的混炼胶硫化速度有所提高;所用软化剂对硫化胶交联密度的影响都不大;添加氟硅油的硫化胶综合力学性能较好;古马隆和齐聚酯均会使硫化胶耐热老化和耐油性能下降,氟硅油则对耐热老化以及耐油性能无明显不利影响。     

土壤中氟的形态与危害

氟是人体必需的微量元素,过量或不足对生物均可造成危害,对土壤中氟的存在形态以及造成的危害进行了综合比较,探讨了氟在土壤中迁移转化的过程,为探索土壤氟污染的防治及危害、土壤中氟化物的迁移、转化特征及氟的环境生物学意义提供依据。     

含氟污水返回过磷酸钙生产系统再利用

为使过磷酸钙副产氟硅酸钠的生产过程中所产生的含氟污水达标排放,南化公司采用了两种处理方法.一种是化学处理,将含氟污水与熟石灰水反应,氟会生成氟化钙沉淀,氟化钙和污水的硅胶经压滤去除;但每年需水处理费50万元左右,年累计产生3000t废渣需外运堆放,产生二次污染.另一种是含氟污水返回过磷酸钙生产系统,用作原料硫酸的稀释水,无二次污染,不仅改善了过磷酸钙的物性,减少防结块剂的用量,而且还降低了硫酸消耗,每年可降低过磷酸钙生产成本240万元;但需解决部分管道、设备的防腐问题.