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1.
王振兴  章亚东  唐平贵 《精细化工》2006,23(10):1023-1026
对反应控制相转移催化剂制备方法进行了改进,催化剂产率可达94%,并用红外光谱(IR)和元素分析对催化剂进行了表征;将催化剂用于以w(H2O2)=34.5%为氧化剂,以质量分数76.7%的工业粗环己烯为原料合成环氧环己烷;探讨了反应时间、反应温度、环己烯与H2O2的摩尔比、催化剂用量、溶剂用量等因素对反应的影响。获得的较佳合成条件(以0.08 mol H2O2计)为:反应温度40℃,反应时间90 m in,催化剂用量0.6 g,n(C6H10)∶n(H2O2)=2.5∶1,溶剂1,2-二氯乙烷70 mL。该条件下环氧环己烷平均选择性为96.1%,环氧环己烷的平均收率达91.7%。将回收的催化剂用于反应,环氧环己烷的平均选择性和平均收率分别为95.3%和90.9%。  相似文献   

2.
邓爱云 《清洗世界》2013,(9):11-15,27
以马来酸酐为原料,以钨酸钠为催化剂合成了聚环氧琥珀酸(PESA)。利用正交试验设计方法分别对环氧琥珀酸和聚环氧琥珀酸的合成工艺条件进行了优化。所得出的环氧琥珀酸的最佳合成工艺条件是:反应温度70℃、反应时间2 h、体系pH=7、m(MAH)∶m(H2O2)=1∶1.2;聚环氧琥珀酸的最佳合成工艺条件是:m(钨酸钠)∶m(环氧琥珀酸)=0.15∶1、聚合反应温度95℃、反应时间2 h。对于合成的PESA,通过静态阻垢试验结果表明,PESA在6 mg/L的投加量下就可达到接近100%的阻垢率,对高钙、高碱的苛刻水质有较好的容忍度,并可以适用于高温下的冷却水系统且可长时间停留。  相似文献   

3.
项东升 《贵州化工》2005,30(2):16-18
苯甲醛与乙酐的Perkin反应合成肉桂酸,首次采用KF/γ-Al2O3固体超强碱催化剂,降低了反应温度,明显缩短了反应时间,最佳反应条件为n(苯甲醛):n(乙酐)=1.0:3.0,反应时间1.5h,反应温度160℃,催化剂用量为苯甲醛质量的0.5%,所得的肉桂酸的产率可达81%以上。该催化剂具有较高的催化活性,易于回收,可重复使用5次以上。  相似文献   

4.
以马来酸酐为原料,过氧化氢为氧化剂,钨酸盐为催化剂合成环氧琥珀酸,考察了反应温度、反应时间、物料配比、氧化剂及催化剂用量对环氧化反应和水解反应的影响规律,研究了提纯方法。结果表明,反应温度65℃,反应时间1.5h,催化剂用量3%(wt%),氢氧化钠与马来酸酐摩尔比2∶1,过氧化氢与马来酸酐质量比1.2∶1,环氧琥珀酸收率88%。采用间接法计算环氧琥珀酸产率,可精确计算收率。甲醇重结晶法可以提纯环氧琥珀酸,所得产率与间接法计算结果基本一致。经红外光谱仪分析确定产物为环氧琥珀酸。  相似文献   

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制备了适于二甲基硅油合成的固体酸催化剂SO42-/ZrO2-A12O3,开发了以固体超强酸SO42-/ZrO2-A12O3为催化剂,以八甲基环四硅氧烷和六甲基二硅氧烷为原料合成二甲基硅油的新工艺。考察了催化剂用量、反应温度、反应时间和脱低沸时间等因素对产品粘度和闪点的影响。实验结果表明:在固定原料配比n(八甲基环四硅氧烷)︰n(六甲基二硅氧烷)=36︰1下,二甲基硅油合成的较佳工艺条件为:催化剂的用量为反应物总质量的2%,反应温度为120℃,反应时间为3 h,脱低沸物时间为3 h。  相似文献   

6.
顺式环氧琥珀酸氢钠的合成与表征   总被引:1,自引:0,他引:1  
以Na2WO4·2H2O为催化剂,30%H2O2氧化马来酸,在75%稀乙醇溶液中合成了顺式环氧琥珀酸氢钠.采用正交实验考察了反应时间、反应温度、催化剂用量和反应液pH等因素对收率的影响,得最佳反应条件:在催化剂用量为0.825g(0.0025mol),pH值为3.5时,60℃下,反应2h,收率最高,为71.46%;并应用HF/6-31G*量子化学从头算方法优化了分子构型.  相似文献   

7.
通过单因素实验方法催化合成了环氧亚麻油,以产品环氧值为考察指标,研究了催化剂种类、反应时间、催化剂用量、甲酸用量、双氧水用量、反应温度对反应的影响.结果表明,以硫酸为催化剂,反应时间8 h,反应温度为65℃,反应物料质量比m(亚麻油):m(甲酸):m(硫酸):m(双氧水)=1:0.06:0.0015:0.65,硫酸0....  相似文献   

8.
以聚乙二醇(PEG–600)和环氧氯丙烷(ECH)为原料,四正丁基氯化铵(TBAC)和氢氧化钠为催化剂,制得聚乙二醇缩水甘油醚;再通过聚乙二醇缩水甘油醚的开环反应制得多羟基聚醚。通过正交试验研究了聚乙二醇缩水甘油醚制备过程中反应时间、原料配比、催化剂用量对环氧值的影响。采用红外光谱、环氧值及羟值对产物进行了表征。结果表明:当n(聚乙二醇)︰n(环氧氯丙烷)︰n(氢氧化钠)︰n(催化剂)=1︰2.5︰3︰0.03,反应时间为1.5 h,反应温度为55℃时,产物有较理想的环氧值。  相似文献   

9.
氟化钾催化DDSA缩合螺双内酯化合物   总被引:1,自引:0,他引:1  
以氟化钾为催化剂 ,催化十二烯基琥珀酸酐 (DDSA)缩合成螺双内酯化合物。考察了催化剂用量、反应温度、反应时间等因素对缩合反应的影响。通过正交实验设计 ,找到了最佳反应条件 :反应温度为 2 4 0℃ ,反应时间为 4 .5h ,催化剂用量为十二烯基琥珀酸酐质量的 0 .8%。实验结果表明 ,在此条件下螺双内酯化合物转化率可达到 93%。通过与其他催化剂的催化活性进行比较 ,氟化钾 >氢氧化钾 >碳酸钠 >氢氧化钠 ,证明了氟化钾具有较好的催化活性。并对缩合成的产品通过酸值测定 ,经红外光谱进行了表征。  相似文献   

10.
本文研究用自制的固体分子筛催化剂催化马来酸酐与甲醇酯化反应合成马来酸二甲酯,目的是研究开发马来酸二甲酯绿色合成新工艺。酯化反应在压力釜内进行,分别考察了反应温度、反应时间、催化剂用量、原料摩尔比等条件对马来酸二甲酯收率的影响。研究结果表明,温度升高有利于马来酸二甲酯的生成,最佳反应温度为105~110℃。适当增加醇酐摩尔配比,延长反应时间和增加催化剂用量均有利于顺丁烯二酸二甲酯的生成,在醇∶酐为3∶1(摩尔比)、反应时间为12h、H-β沸石用量为0.5%(与顺酐的质量百分比)时,二酯得率达到93.41%。H-β沸石催化剂能够重复使用3次。  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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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   

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   

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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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