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1.
李志成  方煜  胡文浩 《广东化工》2012,39(5):300+302-300,302
在对甲苯磺酸催化下、使用环己烷作带水剂,以苯甲酸和二甘醇为原料合成环保增塑剂二甘醇二苯甲酸酯(DEDB)。研究考察了酸醇摩尔比、催化剂用量、带水剂用量和反应时间等因素对产率的影响。确定了最佳工艺条件:n(苯甲酸)∶n(二甘醇)=2.0∶1.1、催化剂用量(以苯甲酸的摩尔数计)3.0%、环己烷12 mL、回流反应时间8 h,目标产品的产率为98.0%。  相似文献   

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以苯甲酸和二甘醇为原料,二(乙酰丙酮基)钛酸二丁酯为催化剂,通过酯化合成二甘醇二苯甲酸酯(DEDB),探索了增塑剂DEDB的最佳合成工艺条件,并通过FT-IR、核磁共振氢谱(1H-NMR)对合成产物进行了结构分析。研究结果表明:反应原料酸醇摩尔比为2∶1.1、带水剂用量为苯甲酸质量含量的18%、催化剂用量为苯甲酸质量含量的3.0%,反应温度为180℃,反应时间为5h,酯化率达到98.2%。  相似文献   

3.
梁世强  穆筱梅 《精细化工》2005,22(9):685-687
以玻璃珠为载体,制备了固体超强酸SO42-/TiO2催化剂,用于催化合成二甘醇二苯甲酸酯(DEDB)。通过实验确定了合成DEDB的适宜工艺条件:回流温度为165~170℃,m(甲苯)/m(二甘醇)=0.5,n(苯甲酸)/n(二甘醇)=2.2,m(催化剂)/m(二甘醇)=0.5,反应时间4 h,在该条件下,酯化率可达99.6%。该催化剂经过10次重复使用,活性每次平均下降2.9%。  相似文献   

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研究了二安替比林基-间溴苯基甲烷(DAmBA)与锰(Ⅶ)的显色反应条件。在磷酸介质中,Mn(Ⅱ)存在下,DAmBM与Mn(Ⅶ)反应生成橙色产物,λmax=480nm。ε=5.10×105L·mol-1·cm-1,锰含量在0.1~1.5μg/25ml符合比尔定律。该体系灵敏度高,具有一定稳定性。食品中的微量锰(Ⅱ)用过硫酸铰氧化为锰(Ⅶ)后用该法测定,结果满意。  相似文献   

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二苯甲酸二甘醇酯(简称DEDB是一种性能优良的增塑剂,其性能稳定,与PVC、聚醋酸乙烯酯、聚乙烯缩了醛等树脂相容性好,增塑效果佳,而且体积电阻率大,耐油污性好.产品成本低,因而具有良好的实用价值。本文介绍利用直接酯化法合成DED,将苯甲酸、二甘醇以一定比例加入到带有搅拌器、分水器及温度计的烧瓶中,用Al2O3作催化剂,在180-210C进行反应,每小时测定酸值一次,反应完毕后进行减压蒸馏,收集0.67kPa下的产品。经多次实验,得到最佳合成工艺条件是:苯甲酸与二甘醇摩尔配比为1:0.8.催化剂用量为苯甲酸量的8%,反应温…  相似文献   

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合成并鉴定了一个新的二安替比林类试剂:二安替比林基-(3-溴)苯基甲烷(DAmBM),研究了它与钒(Ⅴ)的显色条件。在Mn(Ⅱ)和Tween-20存在下,DAmBM与V(Ⅴ)在浓H3PO4介质中产生橙色产物,λmax=490nm。ε=2.44×106L.mol-1cm-1。V(Ⅴ)量在0.1-1.1μg/25ml范围内符合比尔定律。用该体系测定中草药中的V(Ⅴ),结果满意。  相似文献   

7.
崔健 《江苏化工》1998,26(2):20-22
采用改进的Williamson合成反应方法,以二甘醇、氯丁烷及固碱为原料,一步法合成二甘醇单丁醚。就影响醚化反应收率各因素:原料配比、反应温度、反应时间以及催化剂用量进行了探讨,得到最佳的操作条件分别为:n(二甘醇):n(氯乙烷)=5.0 ̄6.0:1.0、反应温度:70 ̄100℃、反应时间:7 ̄9h、n(氯乙烷):n(固碱)=1.0:1.2,在此条件下收率可达85.5%。  相似文献   

8.
二安替比林苯甲烷光度法测定废水中的铬   总被引:3,自引:0,他引:3  
周原  刘新玲  杨明俊 《化学世界》1995,36(11):600-602
本文研究了二安替比林苯甲烷(Dianti-pyrylphenylmethane,简称DAPM)与铬(Ⅵ)的显色反应。在磷酸介质中,在锰(Ⅱ)和吐温-80的协同催化下,铬(Ⅵ)可将DAPM氧化成一种橙黄色产物,其最大吸收波长为483nm,表现摩尔吸光系数为7.38xl0 ̄5L·mol ̄(-1)·cm ̄(-1),铬量在0.1~1.3μg/25ml范围内符合比耳定律。文中初步探讨了反应的机理。用于废水样品中铬的测定,结果满意。  相似文献   

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本文以CTA氧化残事分离出来的混合单元苯羧酸为原料,和二甘醇进行酯化反应,合成铂混合单元苯酸酸二某醇酯增塑剂,考察了反应温度,催化剂用量,反应时间,醇/酸经对反应的影响,得出最佳工艺条件为:反应温度210℃,反应时间7h,催化剂量0.4%,醇/酸为1.5/2(摩尔比)。  相似文献   

10.
陈慕华  陈燕青  陈思  朱新宝 《化工进展》2014,33(5):1201-1204,1241
以活性炭负载钛酸四丁酯[Ti(OBu)4/AC]为催化剂,用于催化合成二甘醇二苯甲酸酯(DEDB)。通过实验确定了合成DEDB的适宜工艺条件:n(BA)∶n(DEG) = 2∶1、催化剂用量为1.25%,带水剂用量为20.0%,反应温度为200℃,反应时间为7h,该反应条件下酯化率可达98.1%。催化重复使用实验表明该催化剂具有良好的稳定性。同时建立了该酯化合成的表观动力学模型,得到反应速率方程为:rA=6.28× 109exp CACB。  相似文献   

11.
Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.  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   

14.
2008~2009年世界塑料工业进展   总被引:4,自引:1,他引:3  
收集了2008年7月~2009年6月世界塑料工业的相关资料,介绍了2008~2009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、环氧树脂、不饱和聚酯树脂)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   

15.
It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.  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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