二氟乙醇的合成方法

介绍了脂肪族含氟中间体二氟乙醇的基本特性,并按照其原料不同,简述了几种基本的合成方法:以二氟乙酸或二氟乙酸酯为原料的金属硼氢化物还原法、以二氟乙酰氯为原料的催化氢化法、以1,1-二氟-2-溴(或氯)乙烷为原料的酯化水解法。其中,以二氟乙酰氯为起始原料,反应试剂易得,条件设备简单,产率较为理想,最为适合工业化生产。     

苯甲酰脲类杀虫剂伏虫隆合成新工艺

以2,4-二氟硝基苯为原料,经过氯化、还原反应合成了3,5-二氯-2,4-二氟苯胺;以2,6-二氯苯腈为原料,经过氟化和水解制得2,6-二氟苯甲酰胺。将2,6-二氟苯甲酰胺与二(三氯甲基)碳酸酯酰化合成2,6-二氯苯甲酰异氰酸酯,再与3,5-二氯-2,4-二氟苯胺加成得到杀虫剂伏虫隆,总收率为75·3%。     

2,2-二氟乙胺的合成研究进展

2,2-二氟乙胺是农药、医药等的关键原料和中间体。本文总结并评述了2,2-二氟乙胺的合成方法。重点介绍了以2,2-二氟-1-氯代乙烷、二氟乙腈和1,1-二氟-2-硝基乙烷和二氟乙醇为原料的合成方法。     

二氟溴乙酰氟的制备研究进展

二氟溴乙酰氟是一种有用的中间体,可用于制备氟橡胶用全氟乙烯基醚、表面活性剂用全氟磺酸、含氟缩聚物的原料中间体,以及润滑剂、溶剂和绝缘材料用全氟化碳醚的原料.其制备路线有四氟乙烯法、偏氟乙烯法、三氟氯乙烯法、二氟乙酰氟法、1,4-二溴六氟-2-丁烯法和全氟烯醚法.     

2,2-二氟乙醇的合成

介绍了2,2-二氟乙醇的性质、用途,分析、比较了已有的2,2-二氟乙醇的合成方法,提出了以1,1-二氟-2-氯乙烷和氟化钾水溶液为原料合成二氟乙醇的生产方法。     

2,3-二氟-4-羟基苯硼酸的合成

本文以邻二氟苯为原料,利用其定位效应,通过与丁基锂、硼酸三甲酯直接作用得到2,3-二氟苯硼酸,再通过与H2O2反应得到2,3-二氟苯酚。以所合成的2,3-二氟苯酚为原料,通过叔丁基二甲基氯硅烷保护酚羟基,再在低温下与丁基锂、硼酸三甲酯等作用得到2,3-二氟-4-羟基苯硼酸,5步反应总产率为83%。     

苯甲酰脲类杀虫剂伏虫隆合成新工艺

伏虫隆是一种苯甲酰脲类杀虫剂,尤其对有机磷、拟除虫菊酯、氨基甲酸酯三类杀虫剂已产生抗性的害虫防治效果更佳。以2,4-二氟硝基苯为原料,经过氯化、还原反应合成了3,5-二氯-2,4-二氟苯胺;以2,6-二氯苯腈为原料,经过氟化和水解制得2,6-二氟苯甲酰胺,将2,6-二氟苯甲酰胺与二(三氯甲基)碳酸酯酰化合成2,6-二氟苯甲酰异氰酸酯,再与3,5-二氯-2,4二氟苯胺加成得到杀虫剂伏虫隆,总收率为75.3%。产物结构经元素分析、IR和1HNMR所表征。该工艺具有原料易得、收率高、质量好、对环境污染小的特点。     

3,5-二氟苯胺的合成方法研究进展

介绍了3,5-二氟苯胺的合成方法,评述了从不同原料出发的10条合成路线的优缺点,建议在我国开发以间苯二胺、2,4-二氟苯胺为原料的合成工艺。     

一种二氟乙酸乙酯的制备工艺

采用连续加料的方式制备二氟乙酸乙酯。以二氟氯乙酸乙酯为原料,在温度和催化剂作用下加氢脱氯,得到二氟乙酸乙酯。并考察了温度和H_2/原料摩尔比对转化率的影响。结果表明反应温度在240℃左右、H_2/原料摩尔比为30,二氟氯乙酸乙酯的转化率最大。     

1,2-二溴-3,3,3-三氟丙烷的制备研究

以3,3,3-三氟丙烯和溴为原料,以1,2-二溴-3,3,3-三氟丙烷为溶剂合成了目标物1,2-二溴-3,3,3-三氟丙烷。讨论了各种反应条件如催化剂、溶剂量、3,3,3-三氟丙烯流量、温度和原料配比对收率的影响。     

受限纳米通道内气泡核化的分子动力学模拟

采用分子动力学方法模拟研究受限纳米通道内液体在固体壁面上的核化生长过程,本文主要研究固体壁面润湿性对液体核化生长的影响并分析了气泡成核机理。结果表明：不同壁面润湿性对气泡核化生长产生较大影响。壁面润湿性强时,近壁面处会形成一层液膜,出现与池沸腾不同的现象,流体在液膜层发生均质核化,气泡核化生长速度较快;壁面润湿性较弱时,液体在近壁面处发生异质核化,气泡核化生长速度相对较慢;壁面润湿性最弱时,在近壁面处会形成一层气膜,热量通过气膜传递给流体,传热效果不佳,液体很难发生核化现象。形成这种现象的原因是壁面润湿性强,近壁面处会形成“类固体”层,热量由壁面经“类固体”层传给通道内流体,传热效果好,此外,“类固体”层越厚传热效果越好。壁面润湿性弱时,近壁面处没有“类固体”层,会形成一层气膜,降低传热效果,影响通道内流体核化生长。     

电气石在环境领域中的研究现状及制膜探索

电气石是电气石矿物族矿物的总称,是一种含硼硅酸盐矿物,其成分复杂,具有特殊的晶体结构,电气石具有压电性、热电性和自发极性。目前电气石广泛应用于环境领域,但国内对此方面的研究仍处于初级阶段。以电气石为原料制备"空气负离子薄膜"的研究是一个新视角,具有较广的应用前景和市场价值。     

Preparation and structures of the poly(vinyl chloride) porous membranes

Formation of membranes from a binary system, poly(vinyl chloride) and dimethylformamide, was studied. Phase separation during membrane formation was caused by absorption of aqueous vapor from the atmosphere. The membrane structure was closely related to the degree of phase separation. The membrane formation process was divided into three stages, i.e., an early stage, a transitional stage, and a late stage. By leaching the solution at the early stage, where the casting solution was still transparent, a membrane with a finger-like structure was obtained. On the other hand, a network structure was obtained by leaching at the late stage which was dependent on the molecular weight and the concentration of poly(vinyl chloride). The membrane structure was predominantly controlled by the mobility of polymer molecules in the casting solution.     

Observation of electron field emission patterns from B-doped diamond films

To develop electron beam sources of carbon materials, field emission patterns were observed in three different setups. The first was a diode-type, in which a carbon specimen was facing to a positively biased fluorescence plate. The second was a triode-type, in which a positively biased grid was placed between them. In the third setup, a commercial electron gun was modified so that it could accommodate a carbon specimen and a grid. A fluorescence plate was placed in a vacuum chamber outside the gun. As the carbon specimen for electron emission source, B-doped diamond films, a single crystal diamond with a B-doped layer, an undoped diamond film and a glass-like carbon both with a fibrous structure at the surface, and a sponge carbon were used. It was found that electron emission from edges was dominant for 1×1 cm diamond films and carbon specimens in the diode-type setup. In the triode-type setup, the edges of the specimens were masked with a Kapton® tape. The electron emission occurred only from some spots on the specimen. In the electron gun setup, it was confirmed that an electron beam was generated, and a fairly uniform circle was seen on the fluorescence plate under defocused situation, while the circle became smaller by adjusting the current of the focusing lens. Although more uniform emission from the electron source materials seemed to be necessary for practical applications, it was demonstrated that an electron beam could be generated even in such a simple setup.     

Modeling of a paper-making wastewater treatment process using a fuzzy neural network

An intelligent system that includes a predictive model and a control was developed to predict and control the performance of a wastewater treatment plant. The predictive model was based on fuzzy C-means clustering, fuzzy inference and neural networks. Fuzzy C-means clustering was used to identify model’s architecture, extract and optimize fuzzy rule. When predicting, MAPE was 4.7582% and R was 0.8535. The simulative results indicate that the learning ability and generalization of the model was good, and it can achieve a good predication of effluent COD. The control model was based on a fuzzy neural network model, taking into account the difference between the predicted value of COD and the setpoint. When simulating, R was 0.9164, MAPE was 5.273%, and RMSE was 0.0808, which showed that the FNN control model can effectively change the additive dosages. The control of a paper-making wastewater treatment process in the laboratory using the developed predictive control model and MCGS (monitor and control generated system) software shows the dosage was computed accurately to make the effluent COD remained at the setpoint, when the influent COD value or inflow flowrate was changed. The results indicate that reasonable forecasting and control performances were achieved through the developed system; the maximum error was only 3.67%, and the average relative error was 2%.     

二氧化钛-聚合物纳米复合膜的制备与光致耗氧行为

合成了一种新型二氧化钛-聚合物纳米复合膜,用于封闭体系中光致好氧研究。以钛酸异丙酯为原料,利用凝胶-水热法制备了TiO2纳米晶粒。将商品级纳米TiO2与凝胶-水热法得到的纳米TiO2分别采用层层涂覆与混合涂膜法与聚合物复合,制各固态TiO2-聚合物纳米复合膜。提出了复合膜的结构,考察了其光稳定性和其存封闭体系中光致耗氧行为,建立了光致耗氧的动力学模型。结果表明：利用光催化原理,复合膜可消耗封闭体系中的氧气：光致耗氧反应可用Langmuir-Hinshelwood气-固相催化反应动力学模型来描述。其动力学表达式符合拟一级反应动力学。     

新型受阻酚类抗氧剂的合成与性能研究

以2,6-二叔丁基苯酚原料,合成了1种新型受阻酚抗氧剂2,6-二叔丁基-4-氨基苯酚,研究了该新型抗氧剂对聚烯烃材料的抗氧化作用。结果表明,以锌粉为还原剂,8.5 %氯化钙水溶液用量为90 mL,溶剂乙醇用量为100 mL, 在80 ℃下反应8 h,新型受阻酚抗氧剂的产率达80 %以上,熔程为112.2~113.3 ℃。该抗氧剂在2种聚烯烃材料中均具有良好的加工稳定性和抗氧化性能,氧化诱导期与市售抗氧剂1076相当,优于抗氧剂BHT;经5次挤出后,添加新型抗氧剂的聚烯烃材料的熔体流动速率变化很小,但拉伸强度和断裂伸长率大幅度提高。     

调节阀流场CFD数值模拟与流道优化

应用三维建模软件对某一广泛应用的套筒型调节阀内部流场建立模型,通过前处理器生成计算网格,应用CFD软件进行离散求解,得到调节阀内部流场的可视化图形,数值模拟不同开度下流量,得到调节阀的流量特性曲线,并与试验测定的数据进行比较分析。结果表明,模拟值与试验值吻合较好,并对流道进行了结构优化,获得了能耗更低的流道结构。     

模外装饰自动换膜机构设计

基于模外装饰工艺原理,对模外装饰自动换膜机构进行了详细设计,其中包含抚平轮和夹紧轮部分、机构固定部分、机架部分和裁刀部分。抚平轮和夹紧轮部分由抚平轮、夹紧轮、轴承、轴承套和摇杆等组成;机构固定部分由电机、压块、压块杆、轴承盖和摇杆等组成,机架部分由滚动导轨副、底板、滚珠丝杆副、步进电机、滚筒支架等组成;裁刀部分由侧板、导向杆、滑块和驱动电机组成。该套模外装饰自动换膜机构能够满足设计要求和实际需要。     

Polymer nanocomposites formation by the use of sodium montmorillonite dispersion in alcohol and a cationic surfactant

To enhance the formation of nanocomposites, we pretreated montmorillonite clay with a high‐boiling‐point alcohol or a combination of the alcohol and a cationic surfactant prior to melt mixing. The polymer matrix was melt‐mixed with sodium montmorillonite treated with alcohol or a combination of the alcohol and a cationic surfactant, and then, the alcohol was removed. This new method was applied to polymethyl methacrylate, polystyrene, polyethylene, and polypropylene compounds. The dual use of a surfactant and an alcohol for the treatment of montmorillonite enabled a high degree of intercalation of montmorillonite layers by polymethyl methacrylate chains, which was not obtained in untreated clay or clay treated with either the surfactant or alcohol individually. The process was not as successful with the polyhydrocarbons. There was some evidence for slightly enhanced intercalation for polystyrene, but there was less evidence for polyethylene and polypropylene. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1951–1957, 2004