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1.
以H3PW6Mo6O40为催化剂,对以环己酮与乙二醇为原料合成环己酮乙二醇缩酮的反应条件进行了研究,较系统地研究了酮醇物质的量比、催化剂用量、反应时间对收率的影响。实验结果表明,在n(环己酮):n(乙二醇)=1.0:1.5,催化剂用量占反应物料总质量的0.8%,反应时间0.75h,带水剂环己烷8mL的条件下,环己酮乙二醇缩酮的收率为84.9%。  相似文献   

2.
硅钨酸掺杂聚苯胺催化剂催化合成环己酮乙二醇缩酮   总被引:9,自引:0,他引:9  
采用回流法制备了硅钨酸(H4SiW12O40)掺杂聚苯胺(PAn)催化剂H4SiW12O40/PAn。通过环己酮和乙二醇为原料合成环己酮乙二醇缩酮,探讨了硅钨酸掺杂聚苯胺催化剂对缩酮反应的催化活性,较系统地研究了原料量比、催化剂用量、反应时间诸因素对产品收率的影响。实验表明:在n(环己酮):n(乙二醇)=1:1.4,催化剂用量为反应物料总质量的0.8%,环己烷为带水剂,反应时间40min的优化条件下,环己酮乙二醇缩酮的收率可达91.2%。  相似文献   

3.
稀土固体超强酸SO42-/TiO2-Y(Ⅲ)催化合成环己酮乙二醇缩酮   总被引:8,自引:0,他引:8  
制备了固体超强酸催化剂SO4^2-/TiO2-Y(Ⅲ).并利用该催化剂催化合成了环己酮乙二醇缩酮.探讨SO4^2-/TiO2-Y(Ⅲ)对缩酮反应的催化活性,较系统地研究了酮醇物质的量比、催化剂用量、反应时间诸因素对产品收率的影响。实验表明:SO4^2-/TiO2-Y(Ⅲ)是合成环己酮乙二醇缩酮的良好催化剂.在n(酮):n(醇)=1:1.5.催化剂用量为反应物料总质量的0.7%,环己烷为带水剂,反应时间1.5h的优化条件下.环己酮乙二醇缩酮的收率可达86.6%。  相似文献   

4.
在微波辐射下,以硫酸氢钠为催化剂,环己烷为带水剂,合成了环己酮乙二醇缩酮。考察了催化剂的用量、反应时间、酮醇物质的量之比、带水剂的用量及微波功率等诸多因素对产品收率的影响。实验表明,固定环己酮0.2mol,在n(环己酮):n(乙二醇)=1.0:1.5,催化剂用量为1.55g,带水剂环己烷为12mL,反应温度135℃,微波功率为500W和反应时间为25min的优化条件下,环己酮乙二醇缩酮的收率可达78.2%。  相似文献   

5.
TiSiW12O40/TiO2催化合成环己酮缩乙二醇   总被引:18,自引:5,他引:13  
杨水金  陈露春  梁永光  孙聚堂 《化学试剂》2003,25(2):100-102,110
报道了以固载杂多酸盐TiSiWl2040/Ti02为多相催化剂,通过环己酮和乙二醇反应合成了环己酮缩乙二醇,探讨TiSiWl2040/Ti02对缩酮反应的催化活性,较系统地研究了酮醇物质的量比,催化剂用量,反应时间诸因素对产品收率的影响。实验表明:TiSiWl2040/Ti02是合成环己酮缩乙二醇的良好催化剂,在n酮:n醇=1:1.5,催化剂用量为反应物料总质量的0.6%,环己烷为带水剂,反应时间40min的优化条件下,环己酮缩乙二醇的收率可达93.8%。  相似文献   

6.
铝交联蒙脱土催化合成环己酮乙二醇缩酮   总被引:2,自引:1,他引:1  
以临安钠基蒙脱土为原料制备了铝交联蒙脱土催化剂,进行了X射线衍射和比表面积分析,将其用于环己酮和乙二醇反应,合成环己酮乙二醇缩酮。系统研究了催化剂用量、酮醇物质的量比、带水剂用量及反应时间等因素对产品收率的影响。结果表明,在n(环己酮)∶n(乙二醇)=1∶1.5、反应时间1 h,催化剂和带水剂环己烷用量分别为反应物料总质量的2%和20%条件下,环己酮乙二醇缩酮收率可达74.0%。  相似文献   

7.
磷钨杂多酸掺杂聚苯胺催化合成环己酮乙二醇缩酮   总被引:1,自引:0,他引:1  
采用浸渍法制备的磷钨杂多酸掺杂聚苯胺H3PW12O40/PAn作催化剂,通过环己酮和乙二醇为原料合成环己酮乙二醇缩酮,探讨了磷钨酸掺杂聚苯胺催化剂对缩酮反应的催化活性,系统地研究了原料量比,催化剂用量,反应时间诸因素对产品收率的影响。实验表明,在n环己酮∶n乙二醇=1∶1.5(物质的量比),催化剂用量为反应物料总质量的0.25%,环己烷为带水剂,反应时间1.0 h的优化条件下,环己酮乙二醇缩酮的收率可达80.4%。  相似文献   

8.
探讨以H3PW6Mo6O40/TiO2-MoO3为催化剂,以环己酮、乙二醇为原料催化合成环己酮乙二醇缩酮反应的催化活性,较系统地研究了酮醇物质量比,催化剂用量,带水剂用量及反应时间等因素对产物收率的影响。实验表明:固定环己酮的用量为0.2 mol时,在n(环己酮)∶n(乙二醇)=1.0∶1.4,催化剂用量为反应物料总质量的1.0%,带水剂环己烷为6 mL,反应时间为60 min的优化条件下,环己酮乙二醇缩酮的收率可达78.9%。  相似文献   

9.
固体超强酸S2O8 2-/SnO2-SiO2催化合成环己酮乙二醇缩酮   总被引:1,自引:0,他引:1  
以固体超强酸S2O82-/SnO2-SiO2为催化剂,通过环己酮和乙二醇反应合成环己酮乙二醇缩酮。较系统的研究了带水剂用量、酮醇摩尔比、催化剂用量、反应时间等因素对产品收率的影响。结果表明在n(酮):n(醇)=1:1.5、环己烷作带水剂(15mL)、催化剂用量为反应物总质量的0.5%、反应时间1.5 h的优化条件下,环己酮乙二醇缩酮的产率为86.9%。  相似文献   

10.
制备了H3PW12O40/TiO2复合催化剂,并利用该催化剂催化合成了环己酮乙二醇缩酮,探讨了H3PW12O40/TiO2对缩酮反应的催化活性,较系统地研究了酮醇物质的量比,催化剂用量,反应时间诸因素对产品收率的影响。实验表明,H3PW12O40/TiO2是合成环己酮乙二醇缩酮的良好催化剂,在n(环己酮)∶n(乙二醇)=1∶1·5,催化剂用量为反应物料总质量的0·5%,环己烷为带水剂,反应时间1·0h的优化条件下,环己酮乙二醇缩酮的收率可达87·9%。  相似文献   

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12.
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   

13.
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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15.
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   

19.
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   

20.
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   

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