《化学工艺学》教学改革探索与实践

根据化学工艺学课程特点,对化学工艺学的教学改革进行了探讨,认为可通过对教材内容精选、改革教学方法、强化实践教学、追踪学科发展、开设专题报告、加强绿色教育等方式,提高学生学习热情,锻炼学生的实际动手能力,培养学生的创新意识,增强教学效果。     

苯甲羟肟酸与水杨羟肟酸的合成与表征

羟肟酸是近年来应用于氧化矿浮选的一类新型捕收剂,在白钨矿、铌钽矿等矿物浮选中起到良好的效果.本次实验以苯甲酸、水杨酸和羟胺为原料合成羟肟酸,并对其进行红外表征.     

Effects of ultraviolet absorbers on the ultraviolet degradation of rice‐hull/high‐density polyethylene composites

In China, rice‐hull powder is widely used as a fiber component to reinforce polymers because of its ready availability and lower cost compared to wood fibers. However, an issue concerning these composites is their weathering durability. In this study, the effects of two ultraviolet absorbers (UVAs), UV‐326 and UV‐531, on the durability of rice‐hull/high‐density polyethylene (HDPE) composites were evaluated after the samples were exposed to UV‐accelerated weathering tests for up to 2000 h. All of the samples showed significant fading and color changes in exposed areas. X‐ray photoelectron spectroscopy and Fourier transform infrared spectroscopy were used to detect surface chemical changes. The results indicate that surface oxidation commenced immediately within the first 500 h of exposure for all of the samples. However, the control rice‐hull/HDPE composites underwent a greater degree of oxidation than those with the UVAs. Scanning electron microscopy revealed that the rice‐hull/HDPE composites degraded significantly upon accelerated UV aging, with dense cracking on the exposed surface. The UVAs provided effective protection for the rice‐hull/HDPE composites, and UV‐326 had a more positive effect on the color stability than UV‐531. The results reported herein serve to enhance our understanding of the efficiency of UV stabilizers in the protection of rice‐hull/HDPE composites against UV radiation, with a view toward improving their formulation. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis mechanisms of poly[styrene‐co‐(acrylic acid)]‐supported TiCl4 catalysts modified by magnesium compounds

Soluble poly[styrene‐co‐(acrylic acid)] (PSA) modified by magnesium compounds was used to support TiCl₄. For ethylene polymerization, four catalysts were synthesized, namely PSA/TiCl₄, PSA/MgCl₂/TiCl₄, PSA/(n‐Bu)MgCl/TiCl₄, and PSA/(n‐Bu)₂Mg/TiCl₄. The catalysts were characterized by a set of complementary techniques including X‐ray photoelectron spectroscopy, Fourier‐transform infrared spectroscopy, X‐ray diffraction, thermogravimetric analysis, scanning electron microscopy, and element analysis. Synthesis mechanisms of polymer‐supported TiCl₄ catalysts were proposed according to their chemical environments and physical structures. The binding energy of Ti 2p in PSA/TiCl₄ was extremely low as TiCl₄ attracted excessive electrons from ? COOH groups. Furthermore, the chain structure of PSA was destroyed because of intensive reactions taking place in PSA/TiCl₄. With addition of (n‐Bu)MgCl or (n‐Bu)₂Mg, ? COOH became ? COOMg‐ which then reacted with TiCl₄ in synthesis of PSA/(n‐Bu)MgCl/TiCl₄ and PSA/(n‐Bu)₂Mg/TiCl₄. Although MgCl₂ coordinated with ? COOH first, TiCl₄ would substitute MgCl₂ to coordinate with ? COOH in PSA/MgCl₂/TiCl₄. Due to the different synthesis mechanisms, the four polymer‐supported catalysts correspondingly showed various particle morphologies. Furthermore, the polymer‐supported catalyst activity was enhanced by magnesium compounds in the following order: MgCl₂ > (n‐Bu)MgCl > (n‐Bu)₂Mg > no modifier. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

彩色防滑涂层——效果很好的交通安全设施

叙述了彩色防滑涂层的国内外发展概况、组成和种类、彩色防滑涂料的技术要求、应用范围及施工建议,并指出彩色防滑涂层是值得大力推广的交通安全设施。     

电器开关用盖类零件多向抽芯注塑模具设计

分析了电器开关用盖类塑件的使用要求和结构特点,介绍了多向抽芯注塑模具的结构组成及工作原理。该模具采用四板式点浇口,采用外侧三向斜导柱抽芯和内侧弹性元件抽芯两种侧抽芯机构,结构合理,运行可靠。     

喜旱莲子草基活性炭制备及其对苯酚吸附性能的研究

利用喜旱莲子草制备活性炭,选择了活化剂、活化剂浓度、碳化时间、碳化温度等作为实验的四个因素,每个因素选取三个水平,采用正交实验法,得出了最佳制备条件:以2 mol/L的H3PO4作为活化剂,碳化温度400℃,碳化时间1 h。比较了不同时间、不同活性炭用量、不同温度下,喜旱莲子草基活性炭对苯酚的吸附效果。此外,动态吸附实验表明:提高活性炭用量(即增加填料高度),降低进水苯酚浓度以及减小进水流量均能相应延长喜旱莲子草基活性炭去除苯酚到达穿透点的时间,从而增加最大吸附容量。     

海南火山岩滤料BAF工艺的高温挂膜启动中试研究

通过构建上向流曝气生物滤池(BAF)污水处理系统,在高温(28～30℃)条件下,试验了基于海南火山岩滤料的BAF处理城市污水的挂膜启动过程。结果表明,高温条件下挂膜启动时间较中低温大大缩短。25 d后挂膜启动完成,此时COD、NH4+-N的去除率分别稳定在80%、98%,出水COD和NH4+-N的质量浓度分别稳定在50 mg/L和5mg/L以下,水质良好且运行稳定,满足GB 18918-2002中规定的一级A排放要求。证明海南火山岩滤料挂膜性能良好,具实用价值。     

我国DSD酸产品标准化工作30年

自1982年原化工部首次颁布了我国DSD酸产品第一部化工部标的化工行业标准）HG2—1436-82以来迄今已有30年。30年来对该标准先订,标准号先后改为HG2279．1992、HG／T2279—2000、HG／T2279-2011。版本标准的主要内容及每次修订的主要内容,详细解读于2012年7月1HG／T2279—2011。准（相当于现行后进行了三次修该文介绍这四个日实施的新标准     

A dissymmetric bis-quaternary ammonium salt gemini surfactant as effective inhibitor for Q235 steel in hydrochloric acid

The inhibition effect and adsorption behavior of a novel dissymmetric bisquaternary ammonium salt (DBAL) for Q235 steel in 1 M hydrochloric acid medium were investigated using weight loss method, polarization and electrochemical impedance spectroscopy (EIS). The result of weight loss method indicates that the inhibition efficiency increased with DBAL concentration and temperature in the studied range. The inhibition efficiency is above 90% at a concentration of 3.28 × 10⁻⁴ M in the temperature range of 298–328 K. The polarization measurements reveal that DBAL is a mix-type inhibitor which mainly inhibits cathodic process. EIS results show that changes in the impedance parameters (R_ct and C_d) were due to the formation of a protective layer on the Q235 steel surface by the adsorption of inhibitor molecules. Adsorption follows the Langmuir isotherm via chemical adsorption on the Q235 steel surface. Thermodynamic and kinetic parameters were evaluated from the effect of temperature on corrosion and inhibition processes to discuss the adsorption mechanism.