烯丙基胺-细菌纤维素的制备及其动力学研究

基于Ce4+引发自由基接枝共聚机理,制备了新型的烯丙基胺-细菌纤维素(al-BC)吸附剂;考察了细菌纤维素(BC)和烯丙基胺加入量、硝酸铈铵(CAN)浓度等对接枝共聚反应的影响并探讨了其接枝动力学过程;以al-BC为吸附剂,研究其对重金属离子Pb2+的吸附性能。结果表明:在CAN浓度25mmol/L、硝酸浓度0.16mol/L、烯丙基胺及BC加入量分别为24mL/L和8g/L、温度40℃、反应时间4h的最优接枝条件下,al-BC接枝率为18.22%;根据实验结果拟合出了反应初期接枝反应动力学方程;在最优吸附条件下,al-BC对Pb2+的吸附能力比BC提高了37.53%。     

一种柔性链状L-Phe树脂的合成与对铜离子的吸附

以氯乙酰化聚苯乙烯微球(PS-acyl-Cl)为大分子引发剂,甲基丙烯酸缩水甘油酯(GMA)和丙烯酰胺(AM)为单体,以原子转移自由基聚合法合成了链状的亲水性环氧聚苯乙烯微球载体(PS-acyl-g-P(AM-GMA)),并与L-苯丙氨酸(LPhe)反应制得一种柔性链状L-Phe树脂。研究了反应时间、原料树脂溶胀时间、溶剂体系、催化剂添加量等对反应的影响。结果表明,随反应时间延长至20 h,增重率增至最大;原料溶胀时间延长至24 h,增重率增至最大;溶剂水较之N,N-二甲基甲酰胺经济且效果好;使用且增加催化剂至20%时,结果最好。在此优化条件下,可得环氧基转化率72%、担载量2.4 mmol/g的L-Phe树脂。研究了L-Phe树脂对Cu2+的吸附,得到最佳条件:Cu2+浓度为100mmol/L,pH为5.8~8.0,饱和吸附时间80 min。树脂最高吸附量为2.0 mmol/g。     

缩水甘油及其封端聚氨酯的合成与表征

以一氯代丙二醇为原料,与氢氧化钠反应合成出缩水甘油,并通过IR、1HNMR对其进行了结构表征,优化了缩水甘油的合成工艺,在最佳合成条件下收率为84.5%.利用制备的缩水甘油与端异氰酸酯基聚氨酯预聚物反应,合成端环氧基聚氨酯,并利用红外光谱对其进行了结构表征.初步讨论了温度对封端反应的影响和缩水甘油加入量对残留-NCO含量的影响,得出最佳反应温度为70℃,最佳反应时间为6h,缩水甘油过量5%为宜.     

淀粉基吸水树脂的制备与性能分析

以淀粉、丙烯酸(AA)和丙烯酰胺(AM)为原料,采用过硫酸铵[(NH_4)_2S_2O_8]作为引发剂,利用N,N-亚甲基双丙烯酰胺(NMBA)进行交联,采用水溶液聚合法制备了AA-AM共聚淀粉吸水树脂。考察了丙烯酸溶液pH、丙烯酸单体用量、引发剂及交联剂用量、反应体系温度与时间对合成树脂性能的影响。通过性能测试和分析得出优化合成条件为:丙烯酸溶液pH=5.5,丙烯酸单体与葡萄糖剩基(AGU)摩尔比为7∶1,过硫酸铵用量为0.35mmol,交联剂用量为0.08571mmol,反应时间为65℃,反应温度为3h。在优化工艺下合成的树脂吸收蒸馏水、0.9%NaCl溶液量分别达到798.6g/g和95.7g/g。采用红外光谱(FT-IR)和热重分析(TG)对合成的树脂进行了表征与分析评价。     

一种带有梳状柔性季铵链结构吸附材料的合成

以氯乙酰化聚苯乙烯树脂为引发剂,甲基丙烯酸缩水甘油酯为单体,通过原子转移自由基聚合(ATRP)法制备得到梳状链环氧树脂,该树脂与盐酸三乙胺反应,一步季铵化即得到含梳状柔性季铵链的强碱性阴离子交换树脂(flex-AIQ-R)。研究了溶液pH、反应时间、反应温度、催化剂及试剂用量等对反应的影响。在溶液pH为8~9,催化剂量为2%,盐酸三乙胺与环氧树脂环氧基的物质的量比为5∶1,溶剂量为10 mL/g,乙醇含量为40%时,于90℃反应10h获得转化率可达85%、担载量为2.78mmol/g的flex-AIQ-R。     

聚乙烯马来酸酐接枝物合成环氧树脂的研究

以低密度聚乙烯接枝马来酸酐(LDPE-g-MAH)为原料与环氧氯丙烷反应合成一种以聚乙烯为主要结构的固态环氧树脂—聚乙烯酯型环氧树脂(LDPE-g-MAH-g-ECH),并利用FT-IR光谱表征了该环氧树脂的化学结构。采用化学分析法研究了反应物料配比、反应温度、反应时间、催化剂用量、碱的用量与浓度等因素对合成反应的影响,确定了合成该环氧树脂的最佳反应条件。该树脂为淡褐色透明粉末,采用化学分析方法测得其环氧值0.24~0.27mmol/g,酸值0.5mg/g。     

水性环氧乳化剂的合成及其乳化性能

以环氧树脂E-51和聚乙二醇(PEG)为原料在引发剂过硫酸钾的作用下合成了水性环氧乳化剂,探讨了反应温度、反应时间、引发剂添加量、E-51与PEG用量比对合成效果的影响,优化了合成条件,并研究了优化条件下制备的乳化剂对E-51的乳化效果.结果表明:优化的合成条件为引发剂添加量0.3%几环氧当量与羟基当量比1.00:1....     

羧基丁腈橡胶改性环氧树脂的合成

采用羧基丁腈橡胶(XNBR)对双酚A型环氧树脂(CYD-128)进行改性,制备了羧基丁腈橡胶环氧基酯增韧剂,探讨了制备过程的反应机理、合成条件、产品转化率等,确定了最佳反应条件.结果表明:反应温度100～120 ℃,反应时间1.5～3.0 h,催化剂用量0.20%～0.30%时,羧基丁腈橡胶转化率较高.     

一种多胺型纤维素吸附剂的制备

以天然纤维素为原料,制备重金属离子吸附材料.秸秆纤维经过碱化、环氧化、烯胺化,制备了多胺型纤维素,对制备该多胺型纤维素的影响因子如温度、时间、碱浓度、环氧氯丙烷用量、二乙烯三胺用量等进行了分析研究,确定了环氧化的最优条件为:反应温度40℃,环氧氯丙烷与秸秆纤维的质量比5:1,二次碱浓度8%,反应时间15h;烯胺化的最优...     

环氧型有机硅季铵盐的合成及性能

合成了含有环氧基团的有机硅季铵盐二乙基-2,3-环氧丙基-[3-(甲基二甲氧基)]硅丙基氯化铵(DEEPSAC),研究了该化合物的表面性能及抗菌性能,表面张力的测定表明该化合物具有很好的表面活性,测得其临界胶束浓度为2.6mmol/L;平板计数实验表明DEEPSAC浓度为0.10%时对大肠杆菌的抑菌率达100%.动力学研究表明,DEEPSAC的合成反应并不符合通常季铵化反应的二级反应规律,反应级数和速率受温度及体系极性的影响,温度较低时呈现阶段反应的特点.     

Design for volume optimization of packaging for durable goods

In the literature, there are several authors arguing for the optimization of the packaging volume as an important factor in distribution efficiency. Within the context of packaging of durable goods, these authors present significant economic savings, usually illustrated by qualitative examples of redesigns. So far, these papers are limited to: (a) the economic aspect of volume (b) packaging for which the main functionality is distribution‐related, and (c) mostly qualitative empirical data. This current paper aims to contribute to this literature by: (a) arguing that volume is also a significant factor from an environmental perspective (b) including packaging for which the main functionality is marketing‐related, and (c) presenting quantitative data of over 1000 packed durable goods, covering consumer electronics, domestic appliances, toys, power tools and furniture. Several strategies for volume optimization are discussed in relation to different packaging functionalities. Copyright © 2011 John Wiley & Sons, Ltd.     

Chemical methods for searching for evidence of extra-terrestrial life

This paper describes the chemical concepts used for the purpose of detecting life in extra-terrestrial situations. These methods, developed initially within the oil industry, have been used to determine when life began on Earth and for investigating the Moon and Mars via space missions. In the case of Mars, the Viking missions led to the realization that we had meteorites from Mars on Earth. The study of Martian meteorites in the laboratory provides tantalizing clues for life on Mars in both the ancient and recent past. Meteorite analyses led to the launch of the Beagle 2 spacecraft, which was designed to prove that life-detection results obtained on Earth were authentic and not confused by terrestrial contamination. Some suggestions are made for future work.     

Optimum policy for warrants for and design of guardrails

An optimum policy for the warrants for and the design of guardrails based on benefit maximizing criteria is presented. It is shown that the strength, the number of classes of standards, and the location of guardrails should be determined simultaneously with due consideration for the nation-wide distribution of roadside dangers and the impact of colliding vehicles. Dynamic programming is used for optimization.     

New set-up for measurement of permeability properties of fibrous reinforcements for RTM

Resin transfer molding (RTM) is becoming increasingly important as a production technique for FRPs. However, the design of molds that assures the production of parts with acceptable quality remains a difficult task. Simulation codes developed for design need reliable input data such as reinforcement permeability. The measurement of this material parameter is still not standardized and thus many different set-ups have been proposed. In this paper a new method will be presented that is much faster and much less operator-dependant than other set-ups. It is a 2D central injection set-up, based on the automatic detection of the flow front position as a function of time. For this purpose, simple electrical sensors were designed and an automated calculation procedure was programmed on a PC-based system. As will be shown, the elements of the permeability tensor are not single valued at a particular fiber volume fraction. Rather, each element displays a broad distribution. More importantly, the variations in the principal permeability values are not correlated since their ratio, the anisotropy, also displays a broad distribution.     

Principles for design of systems of normative documents for microelectronic sensor components

We provide a basis for design and implementation of requirements and conditions for support of quality control, reliability, and testing of microelectronic sensor components; our approach uses normative documents and approriate supplements dealing with the homogeneous group of integrated circuits. We suggest classification of microelectronic sensors (and smart sensors in particular) as a new class of microelectronics. Translated from Izmeritel'naya Tekhnika, No. 3, pp. 12–15, March, 1997.