电化学法制备碘仿的研究

研究碘仿的电化学制法。重点探讨电极材料，电流密度，电解液温度，pH值等因素对碘仿合成的电流效率和产率的影响。碘仿电化学合成的最佳条件为：以石墨为阳极，铅作阴极，电流密度为7.0mA/cm^2,pM=11，电解液配方是在15mL乙醇中加入8g碘化钾，浴温30℃。电流效率达80.3%。产率72.3%。     

电化学法制备碘仿的研究

研究了碘仿的电化学制法。重点探讨电极材料、电流密度、电解液温度、ｐＨ等因素对碘仿合成的电流效率和产率的影响。碘仿电合成的最佳条件为：以石墨为阳极、铅作阴极，电流密度为７．０ｍＡ／ｃｍ＾２，ｐＨ１１，电解液配方是在１５ｍＬ乙醇中加入８ｇ碘化钾，浴温３０℃。电流效率达８０．３％，产率７２．３％。     

长链烷基季铵碱的制备工艺及性能

以烷基叔胺和碳酸二甲酯为原料制备烷基碳酸甲酯铵,再经水解得到烷基碳酸氢铵,通过离子膜连续电解法合成长链烷基季铵碱。以十四烷基三甲基氢氧化铵为例,考察了电解反应温度、电流密度、阳极液浓度、阴极出料液浓度对电流效率的影响,得出其优化工艺条件为:反应温度65℃、电流密度450 A/m2、阳极液浓度1.40 mol/L、阴极液出料浓度为0.15 mol/L,在该条件下电解反应的电流效率可达67%以上;通过1HNMR、IR对产品结构进行了表征,结果表明,合成的产品为长链烷基季铵碱;对得到的长链烷基季铵碱的表面活性、p H值、润湿性、泡沫性等性能进行了研究。     

电合成乙醛酸的研究

以过饱和草酸水溶液为阴极液 ,盐酸溶液为阳极液 ,在隔膜式平行板电解池内草酸电还原得到乙醛酸。考察改变阳极液盐酸溶液的浓度、电解液的电流密度和电解液的流速对生成乙醛酸电流效率的影响。考察催化电极对电合成的影响。结果表明 ,用碳板做电极材料 ,电流密度为 6 6 .7A·m-2 ,电解液流速为 2 6 1mL·min-1,电解温度为 2 0℃时 ,乙醛酸的电流效率可高达80 %以上。     

长链烷基季铵碱的制备工艺及性能研究

以烷基叔胺和碳酸二甲酯为原料制备烷基碳酸甲酯铵,烷基碳酸甲酯铵水解得到烷基碳酸氢铵,再通过离子膜连续电解法合成长链烷基季铵碱。以十四烷基三甲基氢氧化铵为例,考察了电解反应温度、电流密度、阳极液浓度、阴极出料液浓度对电流效率的影响,得出其最优工艺条件为：反应温度65 ℃、电流密度450 A/m2、阳极液浓度1.40 mol/L、阴极液出料浓度为0.15 mol/L,在此条件下电解反应的电流效率可达67%以上;通过1H-NMR、IR对产品结构进行了鉴定,结果表明合成的产品为长链烷基季铵碱;对得到的长链烷基季铵碱的表面活性、pH值、润湿性、泡沫稳定性等性能进行了研究。     

浅议影响离子膜电解槽电流效率的因素

保持最佳的离子膜电解工艺操作条件是离子膜电解槽的操作关键,它能使离子膜长期稳定地保持较高的电流效率和较低的槽电压,进而稳定直流电耗,延长离子膜的使用寿命。本文详细分析了影响离子膜电解槽电流效率的因素,认为电解槽在运行过程中,要保持高的电流效率应做到:高质量的入槽盐水;适宜的阴极液浓度、阳极液浓度和适宜的电流密度;严格控制阳极液PH值;保持适宜的电解槽温度、电解液流量和稳定的高质量的无离子水供应。     

电解法制备活性氯的研究

以石墨为阴极和 Ir Ru Ti贵金属氧化物电极为阳极 ,采用离子隔膜电解装置 ,直接电解低浓度的氯化钠溶液制备活性氯。对氯化钠浓度、表观电流密度、温度、p H值、电解时间和流速在电化学反应过程中对活性氯浓度及电流效率的影响进行了研究。由实验结果得出最佳的试验条件为 :电解温度 2 2°C,电解液浓度 2 0 .0 g/ L,电流密度 4.46m A/ cm2 ,时间 2 h,流速 1 .40 m/ s,p H值 4.2 0～ 5.0 0。另外 ,利用活性氯分别对生活污水和河水进行杀菌消毒 ,测定了杀菌消毒后的生活污水和河水中的 COD值、细菌和大肠杆菌。由于活性氯具有很强的杀菌消毒功能 ,此方法在水处理中将会得到广泛应用     

钛基锡锑氧化物电极在合成偶氮二甲酰胺中的应用

采用热分解法制备的SnO2+Sb2O3/Ti作为阳极材料,以联二脲为原料,电化学氧化法合成出偶氮二甲酰胺。通过单因素实验和正交实验研究了电流密度、电量、NaBr的质量浓度和H2SO4的浓度以及反应温度对偶氮二甲酰胺的产率和电流效率的影响。得出最佳工艺条件:电流密度2 300 A/m2,电量12 350 C,NaBr的质量浓度和H2SO4的浓度分别为8 g/L和1.47 mol/L,温度40℃。在最佳条件下,偶氮二甲酰胺的产率达94%,质量分数97%,电流效率89%。此外,SnO2+Sb2O3/Ti电极在NaBr和H2SO4的溶液中的循环伏安测试结果表明,吸附溴原子Brad复合成溴的步骤控制电合成偶氮二甲酰胺的反应速度。整个电极过程包括电子转移及后续的化学反应(EC机理)。     

电解法制取红矾钠的研究

介绍了用离子膜电解槽电解工业铬酸钠溶液合成重铬酸钠的过程。考察了电流密度、电解温度、阳极液初始浓度、阴极液初始和最终浓度对电流效率和直流耗电量的影响。得出了电解反应的最佳条件     

高铁酸钠的电化学合成及铁阳极钝化机理研究

以铁片为阳极、金属钛板为阴极,采用电化学氧化法合成高铁酸钠,研究了NaOH电解液浓度、制备温度和电流密度对高铁酸钠生成的影响及机理,并探析了高铁酸钠制备过程中铁阳极钝化的机理。结果表明,提高NaOH浓度和制备温度不仅有利于高铁酸钠的生成,同时也有利于提高电流效率;提高电流密度虽会增加高铁酸钠的生成量,但也会显著降低电流效率。综合考虑电流效率和制备成本,高铁酸钠的最佳制备条件为：NaOH浓度为14 mol/L、温度为45℃、电流密度为5 mA/cm²。在最佳制备参数下电解后,利用FESEM-EDS和XPS分析了铁电极的表面性质,长时间电解后的铁阳极表面生成了铁氧化物,且钝化后的铁阳极表面存在Fe²⁺和Fe³⁺。电化学氧化合成高铁酸钠过程中,铁阳极钝化生成Fe₃O₄是阳极失效的主要原因。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。