无水乙醛肟的制备

乙醇肟是生产农药灭多威的中间体,也是重要的有机合成试剂和分析试剂[1]。用于有机合成的乙醛后有时必须要求无水（如：与酰氯和异氰酸酯的反应）,而目前国内市场提供的乙醇肟为含量40％左右的水溶液,不能满足需要,为此,我们对无水乙醛股的制备做了研究。无水乙醛肟可由相应乙醛肟水溶液制备。乙醛肟水溶液由盐酸羟胺或硫酸羟胺与乙醛反应而得。本文用盐酸羟胺和乙醛反应所得已醛肟水溶液经萃取、分离、蒸馏制备无水乙酸肟,取得了较好的结果。1实验部分1.1试剂与仪器．乙醛为分析纯;盐酸羟胺、氢氧化钢和二氯甲烷均为化学纯。CR－3…     

2-噻吩乙胺的合成

噻吩与N ,N 二甲基甲酰胺在三氯氧磷存在下反应得到 2 噻吩甲醛 ,产率为 6 2 % ;一氯乙酸和异丙醇反应得到一氯乙酸异丙酯 ,产率为 5 5 % ;2 噻吩甲醛与一氯乙酸异丙酯通过Darzens反应得到 2 噻吩乙醛 ,2 噻吩乙醛与盐酸羟胺反应得到 2 噻吩乙醛肟 ,产率为 72 % ;2 噻吩乙醛肟还原得到 2 噻吩乙胺 ,产率为 6 1%。通过质谱分析、薄层分析等方法初步证明了产物的结构。     

硝基乙醛肟及其盐的合成与表征

以硝基甲烷为原料,在强碱溶液中反应得到硝基乙醛肟钠盐,再酸化得到硝基乙醛肟,收率75.5%,并采用红外光谱、核磁共振光谱、元素分析进行了结构表征;分析了反应历程,优化了反应条件,确定适宜反应条件为:n(CH3NO2)∶n(NaOH)为0.6∶1,反应时间20 min,反应温度50℃,溶液pH 1.5。利用硝基乙醛肟的酸性,设计并合成两种硝基乙醛肟衍生物。     

工业乙醛含量测定方法的探讨

利用乙醛与盐酸羟胺反应生成醛肟及盐酸,再用氢氧化钠滴定,从而测定乙醛含量。该方法具有准确、快速等特点,相对标准偏差不大于0.1%,适用于工厂进行常量分析。     

2-噻吩乙胺合成新工艺

2-噻吩乙醇用SiO2负载的PCC(氯铬酸吡啶)氧化得2-噻吩乙醛,不经提纯,进一步与盐酸羟胺反应得2-噻吩乙醛肟,最后经NaBH4/CuSO4)/amberlyst-15还原得2-噻吩乙胺,总收率76.5%。     

间三氟甲基苯乙酮的合成工艺研究

以间三氟甲基苯胺为原料,经重氮化、偶合加成及水解合成间三氟甲基苯乙酮,总收率89%;并对水解反应的副产物盐酸羟胺与乙醛反应生成乙醛肟后进行了回收,回收率90.5%,实现了乙醛肟的大部分再生。     

红霉素A制备红肟的研究

研究红霉素肟的合成和鉴定,用红霉素A与盐酸羟胺反应,所得产物用碱中和,重结晶后得红肟,用质谱、核磁共振、元素分析鉴定产物,结构与红肟相符,并且用正交实验法确定最佳方案。实验结果表明:反应温度72℃、pH6.4、反应时间36hr、红碱与盐酸羟胺的摩尔比为1∶6为最佳合成条件。     

卤代乙醛缩二乙醇的合成

以醋酸乙烯酯、乙醇、氯气为原料,采用一锅煮方法合成氯乙醛缩二乙醇,同时用正交实验法优化了关键步骤氯乙醛和乙醇的缩合反应条件,得到优化条件为:醋酸乙烯酯与乙醇的比为1:5,缩合反应时间3h,缩合反应温度60℃,中和到pH值为6,此条件下产品收率达83%.并且在相同的实验条件下对其它卤代乙醛缩二醇的合成进行了初步的探讨,产品收率在60～80%之间.     

姜黄素双肟的简易合成方法研究

采用微波加热法,在乙醇水溶液中,分2次加入碳酸钠,从姜黄素和盐酸羟胺合成姜黄素双肟。当盐酸羟胺、姜黄素、碳酸钠的摩尔比为1.3∶1∶0.65,微波输出功率为650W,反应温度为78℃时,微波加热反应35min,姜黄素双肟的合成产率可达87.2%。     

乙醛肟除氧及对A3钢电极电化学性能的影响

研究了除氧剂乙醛肟 (AO)在水中形成溶液的质量浓度、温度、pH值对水中除氧和对A3钢电极电化学性能的影响。对比了用氨水 (NH3·H2 O)和氢氧化钠 (NaOH)作pH值调节剂 ,乙醛肟溶液对A3钢电极电化学行为的作用 ;比较了乙醛肟 (AO)、联氨 (N2 H4)和对苯二酚 (HQ)三种除氧剂对A3钢电极的钝化作用 ,次序为 :AO >HQ >N2 H4。结果表明 ,当 ρ(乙醛肟 ) =175 .0mg L ,水中氧含量达到最低〔ρ(O2 ) =3.4mg L〕。当温度为 75～ 90℃时 ,乙醛肟能够与氧快速反应。当 ρ(AO)=5 0 .0mg L、pH 11.0时 ,A3钢电极腐蚀电流密度jcorr=4.5 81μA cm2 ,钝化性能较好。     

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。