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1.
研究了用活性炭固载磷钨酸催化合成己二酸二丁酯的反应。考察了催化剂固载量、催化剂用量、酸醇比、反应时间、带水剂用量对酯化率的影响,并结合正交试验得到了反应的最佳条件。结果表明活性炭固载磷钨酸是合成己二酸二丁酯的有效催化剂。在n(己二酸)n(正丁醇)=1∶3.5,催化剂用量1.5g,反应时间3.0h,带水剂环己烷10mL,反应温度96~108℃的优化条件下,酯化率可达97.2%,催化剂可重复使用。  相似文献   

2.
以固体超强酸S2O82-/TiO2为催化剂、冰乙酸和正丁醇为原料合成乙酸正丁酯,考察反应条件对酯化率的影响。结果表明,最佳反应条件n(醇)∶n(酸)=1.4∶1,催化剂用量0.5 g(冰乙酸用量0.2 mol),过硫酸铵浓度0.75 mol.L-1,115~117℃反应1.5 h,酯化率达99%以上。催化剂可重复使用,且对设备腐蚀程度较小。  相似文献   

3.
在氧化镓固载量为20%,500℃焙烧2 h的条件下制备了硅胶固载氧化物型非均相酯化催化剂Ga2O3/S iO2,用于催化合成乙酸丁酯,考察了催化剂用量、n(正丁醇)∶n(乙酸)、环己烷用量、反应时间、带水剂用量和催化剂重复使用性等因素对酯化率的影响。结果表明,该催化剂催化合成乙酸丁酯的适宜反应条件为:乙酸0.2 mol,n(正丁醇)∶n(乙酸)=1.8,催化剂1.25 g,回流反应1 h,酯化率达99.62%。  相似文献   

4.
以乳酸与醇的酯化反应、酒石酸与醇的酯化反应及羧酸与环氧氯丙烷得开环酯化反应为模型反应 ,研究了改性片麻岩作为催化剂对上述反应的催化性能。在n (羧酸 )∶n(醇 ) =1 0∶5 2的条件下发生酯化反应 ,羧酸转化率不低于 90 % ,而且基本不发生羟基酸分子间的酯化反应。改性片麻岩对羧酸的酯化反应具有催化作用 ,而且副反应少 ,易于分离 ,无环境污染  相似文献   

5.
活性炭固载氯化铁催化合成柠檬酸三乙酯   总被引:3,自引:0,他引:3  
以活性炭固载氯化铁为催化剂,用柠檬酸和乙醇合成了柠檬酸三乙酯。考察了催化剂用量、酸醇比、反应时间对酯化反应的影响,确定了优化反应条件:以0.3mol柠檬酸为基准,催化剂8.0g,n(柠檬酸)∶n(乙醇)为16∶.0,反应时间为9h,收率87.0%,催化剂易回收,可重复使用,不污染环境。  相似文献   

6.
采用1,4-丁二醇、马来酸酐、十八醇为主要原料,合成出一种双子表面活性剂1,4-丁二醇双琥珀酸十八醇双酯磺酸钠.此化合物的合成由两步酯化以及一步磺化反应组成,双酯化反应采用TiO_2负载磷钨酸(PW_)12)/TiO_2)为催化剂.通过正交实验确定了1,4-丁二醇双马来酸十八醇双酯合成的优化反应条件为:n(1,4-丁二醇双马来酸单酯)∶n(十八醇)=1.00∶2.20,催化剂用量ω(PW_(12)/TiO_2)=1.5%,反应温度150 ℃,反应8 h,酯化率达到95.8%,产率为82.4%.通过正交实验确定了磺化反应的优化条件为:双酯与NaHSO_3物质的量比1.00∶3.00;反应4 h;反应温度90 ℃;催化剂(CTAB)用量1.5%,磺化率达到92.7%,产率为74.9%.  相似文献   

7.
王守庆 《应用化工》2005,34(6):369-370
以固体超强酸SO42-/TiO2为催化剂,以苯乙酸和月桂醇为原料,直接合成苯乙酸月桂醇酯,研究探讨了原料摩尔比、反应时间、催化剂用量等工艺条件对苯乙酸月桂醇酯收率的影响。结果表明,最佳反应条件为:醇酸摩尔比3.0∶1,催化剂用量5%,反应时间3h,酯化率可达90.8%。  相似文献   

8.
华平  李建华  张跃军 《精细化工》2004,21(2):104-107
采用控制酯化率和非外加相转移催化剂在常压进行反应的方法合成了月桂醇聚氧乙烯醚(7)己基磺基琥珀酸混合双酯钠。最佳工艺条件为:n〔月桂醇聚氧乙烯醚(7)〕∶n(顺酐)=1 00∶1 10,于130℃下单酯化反应2 5h,得到产率为99 6%的单酯化产物。n(己醇)∶n(顺酐)=4 0∶1 0,于170℃下双酯化反应2 0h,得到产率为95 8%的双酯化产物。n(亚硫酸氢钠)∶n(顺酐)=1 10∶1 00,加热介质温度为170℃下磺化反应2 5h。测得产物的表面张力、临界胶束浓度、乳化力、渗透力、分散力、耐硬水性能分别为30 7mN/m、3 548×10-5mol/L、3 5min、3 7s、59 5%和14min。与磺基琥珀酸双己酯钠盐(DHSS)和月桂醇聚氧乙烯醚(7)磺基琥珀酸单酯二钠盐(LESS)进行了性能对比。结果表明:分散力、乳化力和耐硬水性能较DHSS均得到了改善,渗透性能较LESS得到了较大的提高。  相似文献   

9.
华平  李建华  戴宝江 《化学试剂》2007,29(8):459-462
通过控制酯化率和不外加相转移催化剂在敞开体系中进行酯化、磺化的方法合成了月桂醇聚氧乙烯醚(5)辛基磺基琥珀酸混合双酯钠,最佳工艺条件为:n(月桂醇聚氧乙烯醚(5))∶n(顺酐)=1.00∶1.10,于110℃下单酯化反应2.5h,得到产率为99.7%的单酯化产物;n(二乙基辛醇)∶n(顺酐)=3.0∶1.0,于170℃下双酯化反应4h,得到产率为94.2%的双酯化产物;n(亚硫酸氢钠)∶n(顺酐)=1.10∶1.00,加热介质温度为160℃下磺化反应4h,可使双酯化产物完全磺化得到标题化合物。测定了产物的表面张力、临界胶束浓度、耐硬水能力、乳化力、渗透力、分散力、钙皂分散力和去油污力,并与磺基琥珀酸二辛酯钠盐(快T)和月桂醇聚氧乙烯醚(5)磺基琥珀酸单酯二钠盐(LESS5)进行了比较。结果表明:其耐硬水能力、分散力、乳化力、钙皂分散性能和去油污性能均较快T有所改善;与LESS5相比,渗透性能得到了较大提高。  相似文献   

10.
华平  戴宝江  吴东辉  刘平 《精细化工》2007,24(10):956-960
采用控制酯化率和非外加相转移催化剂在敞开体系中进行反应的方法,合成了月桂醇聚氧乙烯醚(9)辛基磺基琥珀酸混合双酯钠。最佳工艺条件为:n〔月桂醇聚氧乙烯醚(9)〕∶n(顺酐)=1.00∶1.10,于140℃单酯化反应2.0 h,得到产率为99.8%的单酯化产物。n(2-乙基己醇)∶n(顺酐)=4.0∶1.0,于加热介质温度240℃条件下双酯化反应5.5 h,得到产率为94.4%的双酯化产物。n(亚硫酸氢钠)∶n(顺酐)=1.10∶1.00,加热介质温度210℃条件下,磺化反应6 h得终产物。测得产物的表面张力为32.5 mN/m、临界胶束浓度为1.1×10-4mol/L、耐硬水能力为24 m in、乳化力为3.3 m in、渗透力为3 s、分散力为90.5%、钙皂分散力为13%、去油污力为99.1%。与磺基琥珀酸二辛酯钠盐(快T)和月桂醇聚氧乙烯醚(9)磺基琥珀酸单酯二钠盐(LESS)进行性能对比,结果表明:耐硬水能力、分散力、钙皂分散性能和去油污性能较快T均得到了改善,渗透性较LESS得到了提高。  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   

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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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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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