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1.
采用直接浸清一焙烧法,制备了SO4^2--TiO2/β-沸石催化剂。并以其催化苯乙酮和乙二醇合成了苯乙酮乙二醇缩酮、考察了催化剂的焙烧温度、TiO2负载量、催化剂用量、原料配比、带水剂的种类和用量、田流时间对反应的影响。最佳的反应条件为:催化剂焙烧温度500℃、TiO2负载量10%(质量分数)、催化剂用量1.1g、n(苯乙酮);n(乙二醇)=1:1.2、甲苯20mL、回流时间1.5h。在最佳反应条件下,苯乙酮乙二醇缩酮地度为99.6%,收率可达98.8%.SO4^2-TiO2/β-沸石催化剂制备简单、催化活性高、重复使用性好.  相似文献   

2.
稀土固体超强酸催化合成草酸二丁酯   总被引:15,自引:0,他引:15  
文艺  蒋涛  陆敏 《化工时刊》2005,19(2):30-32
以稀土固体超强酸La^3 /TiO2/SO4^2-为催化剂,催化酯化合成草酸二丁酯。考察了酯化温度、正丁醇与草酸物质的量比、带水剂苯用量、反应时间、催化剂用量等因素对反应的影响。结果表明:在120℃,正丁醇与草酸物质的量比为4,带水剂苯用量为15mL/0.1mol草酸,反应时间为2.5~3h,催化剂用量为0.8g/0.1mol草酸的条件下,草酸二丁酯收率大于93.7%。  相似文献   

3.
采用直接浸渍-焙烧法,制备了SO2-4-TiO2/β-沸石催化剂,并以其催化苯乙酮和乙二醇合成了苯乙酮乙二醇缩酮.考察了催化剂的焙烧温度、TiO2负载量、催化剂用量、原料配比、带水剂的种类和用量、回流时间对反应的影响.最佳的反应条件为:催化剂焙烧温度500℃、TiO2负载量10%(质量分数)、催化剂用量1.1 g、n(苯乙酮):n(乙二醇)=1:1.2、甲苯20 mL、回流时间1.5 h.在最佳反应条件下,苯乙酮乙二醇缩酮纯度为99.6%,收率可达98.8%.SO2-4-TiO2/β-沸石催化剂制备简单、催化活性高、重复使用性好.  相似文献   

4.
采用直接浸渍-焙烧法,制备了SO42--TiO2/β-沸石催化剂,并以其催化苯乙酮和乙二醇合成了苯乙酮乙二醇缩酮。考察了催化剂的焙烧温度、TiO2负载量、催化剂用量、原料配比、带水剂的种类和用量、回流时间对反应的影响。最佳的反应条件为:催化剂焙烧温度500℃、TiO2负载量10%(质量分数)、催化剂用量1.1 g、n(苯乙酮)∶n(乙二醇)=1∶1.2、甲苯20 mL、回流时间1.5 h。在最佳反应条件下,苯乙酮乙二醇缩酮纯度为99.6%,收率可达98.8%。SO42--TiO2/β-沸石催化剂制备简单、催化活性高、重复使用性好。  相似文献   

5.
稀土固体超强酸SO4^2-/TiO2/La^3+合成氯乙酸正丁酯   总被引:3,自引:0,他引:3  
以稀土固体超强酸SO4^2-/TiO2/La^3 为催化剂,氯乙酸与正丁醇为原料合成氯乙酸丁酯,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。实验结果表明,SO4^2-/TiO2/La^3 是合成氯乙酸正丁酯的良好催化剂,n(丁醇)/n(氯乙酸)=2.0,催化剂的用量为酸质量的2.5%,环己烷的用量为反应液总物质的量的15%。反应时闻2.0h,反应温度125-139℃,氯乙酸正丁酯的收率达到88%。  相似文献   

6.
佟以超 《贵州化工》2006,31(5):31-33
采用沉淀-浸渍方法制备了固体超强酸SO42--TiO2/Al2O3。以SO42--TiO2/Al2O3固体超强酸催化剂,通过环己酮和1,2-丙二醇的缩合反应,合成了环己酮1,2-丙二醇缩酮,考察了催化剂的活化温度、TiO2的负载量、反应物配比、催化剂用量、反应时间、带水剂用量对缩合反应的影响。  相似文献   

7.
沉淀法由Fe(NO3)3、Al(NO3)3、Zn(Ac)2、ZrOCl2和H2 SO4制备SO42-/Fe2O3/Al2O3/ZnO/ZrO2催化剂,用于催化合成苯乙酮乙二醇缩酮,研究了醇酮摩尔比、反应时间、带水剂用量、催化剂用量等对产品收率的影响.结果表明,在n(苯乙酮)∶n(乙二醇)=1∶1.2,苯乙酮物质的量为0.2 mol,催化剂的量是反应物料总质量的1.5%,带水剂甲苯20 mL,100~120℃回流反应60 min的条件下,苯乙酮乙二醇缩酮的收率达98.8%.  相似文献   

8.
SO4^2— —TiO2/Al2O3超强酸催化合成新型香料   总被引:1,自引:0,他引:1  
通过浸渍法制备了SO4^2- -TiO2/Al2O3固体超强酸催化剂,用Hammett指示剂法测定了其酸强度;以乙酰乙酸乙酯和1,3-丙二醇、1,3-二醇为原料,合成了新型香料2-甲基-2-乙酸乙酯基-1,3-二氧六环和2,4-二甲基-2-乙酸乙酯基-1,3-二氧六环,考察了催化剂的焙烧温度、TiO2的负载量、反应温度、反应物配比、催化剂用量等因素对反应的影响以及催化剂的重要使用性。结果表明,在425-575℃温度范围内,SO4^2- -TiO2/Al2O3体系可以形成超强酸;在新型香料的合成中具有催化活性高、催化速度快、化学稳定性好,重复使用性佳、无环境污染;在最佳条件下,两种香料的收率分别可达83.5%和83.6%,质量分数为99.1%。  相似文献   

9.
以纳米氧化物为前驱体制备固体超强酸催化剂SO4^2-/Fe2O3、SO4^2-,Al2O3、SO4^2-/TiO2和SO4^2-/ZrO2,其Hammett酸强度常数均小于-12.14。将固体超强酸SO4^2-/Fe2O3、SO4^2-,Al2O3、SO4^2-/TiO2和SO4^2-/ZrO3用于催化苯甲醛与乙酸酐的缩醛反应,考察催化剂制备过程中硫酸浓度和活化温度对缩醛收率的影响,结果表明:采用SO4^2-/Fe2O3为催化剂,硫酸浓度为1.0mol/L、活化温度为500℃时催化效果最好,缩醛收率达99.2%。  相似文献   

10.
张晓丽  任立国 《农药》2006,45(5):313-315
通过直接浸渍焙烧法等过程,制备了SO4^2--TiO2/Al2O3新型固体超强酸催化剂,用Hammett指示剂法测定了其酸强度;以邻苯二酚和异丁醛为原料合成了呋喃酚中间体2-异丙基-1,3-苯并二氧五环;考察了催化剂的活化温度、TiO2的担载量、催化剂用量、原料配比和带水剂等因素对反应的影响。结果表明,在425℃~575℃温度范围内焙烧的SO4^2--TiO2/Al2O3样品可以形成固体超强酸体系,且在邻苯二酚与异丁醛的缩合反应中具有较高的催化活性、化学稳定性好、无环境污染。在最佳反应条件下,产品收率可达91.5%。  相似文献   

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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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14.
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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17.
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   

18.
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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