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二硫化二苯并噻唑的催化合成 总被引:1,自引:0,他引:1
以2-巯基苯并噻唑和氨水为原料,双氧水作氧化剂,经催化剂A进行催化,合成了二硫化二苯并噻唑。通过考察催化剂种类、催化剂用量、氨水用量、物料配比、反应时间和反应温度对产率的影响,得出适宜的工艺条件为:选用催化剂A,用量为2-巯基苯并噻唑的1%,氨的加入量为n(2-巯基苯并噻唑)∶n(氨水)=1∶6.0,双氧水用量为n(2-巯基苯并噻唑)∶n(双氧水)=2∶1.2,反应时间3 h,反应温度50℃。在此条件下,二硫化二苯并噻唑的产率为90.7%,熔点为165.3~168.7℃。二硫化二苯并噻唑粗品通过甲苯进行一次重结晶后,熔点可达173.6~175℃。 相似文献
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实验采用双氧水?乙酸氧化体系对模拟汽油中噻吩进行氧化脱硫,以四丁基溴化铵(TBAB)为相转移催化剂,质量分数30%的过氧化氢水溶液为氧化剂,乙酸为助氧化剂,在温和的条件下将模拟汽油中的噻吩氧化为砜类、亚砜类等极性较强的物质,并以N-甲基吡咯烷酮(NMP)为萃取剂将其萃取出来。考察了反应时间、反应温度、相转移催化剂用量等工艺条件对脱硫效果的影响。结果表明,在20 mL含硫量为500μg/g的模拟汽油中最优的氧化脱硫条件为:n(噻吩):n(双氧水)=1:4,n(双氧水):n(乙酸)=5:3,四丁基溴化铵的质量为0.03 g,室温下反应3 h,脱硫率达89.10%。 相似文献
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多步法合成苯酚中需加入酸及有机试剂,容易造成环境污染。在TS-1分子筛与过氧化氢形成的体系中苯一步羟基化合成苯酚的方法,由于反应条件温和,绿色环保,引起了研究者的关注,但目前的文献报道都基于单一溶剂体系,研究结果各有差异。在甲醇-水两元混合体系中,通过改变两者比例来调整溶液极性,采用TS-1分子筛为催化剂,双氧水为氧化剂,研究了TS-1分子筛直接催化苯羟基化制苯酚的反应。结果表明,当n(水)∶n(甲醇)=0.78、反应时间4h、催化剂用量TS-1/苯为17.5g/mol、n(过氧化氢)∶n(苯)=4.76、反应温度为60℃,苯酚的收率在甲醇-水体系中明显优于单一溶剂,并在此条件下,加入冰醋酸量为n(冰醋酸)∶n(苯)=0.31时,苯酚收率可达12.82%。 相似文献
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《化工进展》2016,(1)
以乙二醇和二氯亚砜为原料,在多相催化剂三氯化钌和氧化剂作用下合成1,3,2-二唑噻吩-2,2-二氧化物。用1H核磁共振谱和红外吸收光谱对1,3,2-二唑噻吩-2,2-二氧化物进行了表征。考察了氧化剂种类、原料摩尔比、反应温度、反应时间、氧化剂用量和催化剂用量对目标产物收率的影响,得到较优的操作条件为:用高碘酸钠作氧化剂、n(二氯亚砜)∶n(乙二醇)=1.2∶1、反应温度40℃、反应时间60min、m(高碘酸钠)∶m(乙二醇)=3∶1、催化剂用量为乙二醇质量的0.2%。在此条件下,收率达81.25%。该工艺在合成路线方面具有副产少、毒性小、收率高的优点,具有更好的实际应用价值。 相似文献
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M. S. J. Simmonds W. M. Blaney F. Delle Monache M. Marquina Mac-Quhae G. B. Marini Bettolo 《Journal of chemical ecology》1985,11(12):1593-1599
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. 相似文献
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Cheng-Le Zhao Shane Porzio Alan Smith Haiyan Ge H. T. Davis L. E. Scriven 《Journal of Coatings Technology and Research》2006,3(2):109-115
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. 相似文献
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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. 相似文献
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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. 相似文献
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中蓝晨光化工研究院有限公司《塑料工业》编辑部 《塑料工业》2009,37(3)
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. 相似文献
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中蓝晨光化工研究院《塑料工业》编辑部 《塑料工业》2007,35(3):1-25,67
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。 相似文献