微波辐射二甲苯磺酸催化合成乙酸异戊酯的研究

介绍了一种在微波辐射条件下,以废弃溶剂中二甲苯磺化得二甲苯磺酸为催化剂,合成乙酸异戊酯的方法;探讨了不同反应条件对乙酸异戊酯酯化率的影响,实验结果表明:当微波辐射功率为400 W,催化剂用量为0.9 g(异戊醇的反应摩尔数为0.1 mol),异戊醇与乙酸摩尔比为1︰2.0,反应时间为10 min,乙酸异戊酯的酯化率可达95.7%。     

磺化硅胶催化合成乙酸系列酯的研究

磺化硅胶是一种以化学键键合而成,性能稳定的固体酸催化剂.文章以合成乙酸异戊酯为探针反应,考察磺化硅胶用量、原料配比、回流时间以及催化剂的重复使用次数对反应酯化率的影响,并将磺化硅胶用于催化合成乙酸系列酯.实验得到乙酸异戊酯的最佳合成条件为∶催化剂用量为反应物总质量的1.5％,n（乙酸）∶n（异戊醇）=1∶1.5,回流时间为60 min,反应的酯化率可达97.1％,催化剂重复使用8次后的酯化率仍达80.0％.根据参考文献的最佳条件合成了乙酸系列酯的结果表明：磺化硅胶对乙酸系列酯的合成具有良好的催化活性.     

SO2-4/Sb2O3/SiO2复合固体超强酸催化合成乙酸异戊酯

以乙酸和异戊醇为原料,固体超强酸SO2-4/Sb2O3/SiO2作催化剂,催化合成乙酸异戊酯.考察了醇酸比、催化剂用量、反应温度与反应时间对酯化反应的影响.结果表明,乙酸异戊酯的最佳合成条件为:n(异戊醇) ∶n(乙酸)=1.4 ∶1,催化剂用量为1.2 g,反应时间4 h,反应温度108～112 ℃,在此条件下酯化率可达95.7%.并用IR手段对产品进行了确证.     

甘蔗渣炭基固体酸的制备及催化合成乙酸甲酯研究

以甘蔗渣为原料通过炭化-磺化的方法制备了甘蔗渣炭基固体酸,探讨了制备工艺条件对固体酸催化剂性能的影响。以正交实验对酯化反应温度、固体酸加入量、酸醇物质的量比、反应时间等影响合成乙酸甲酯的因素进行了优化,并考察了催化剂的稳定性。实验结果表明,制备固体酸催化剂较合理的条件为:炭化温度300℃,炭化时间2.0 h,磺化温度90℃,磺化时间8.0 h。正交实验结果表明,在催化剂用量为乙酸质量的3%、酯化反应时间为2.5 h、n(乙酸)∶n(甲醇)=1∶3、酯化反应温度为65℃的条件下,乙酸转化率为86.5%,且催化剂的稳定性良好,可循环使用7次。该研究结果为乙酸甲酯的合成提供了一种新型催化剂。     

SO_4~(2-)/Sb_2O_3/SiO_2复合固体超强酸催化合成乙酸异戊酯

以乙酸和异戊醇为原料,固体超强酸SO24-/Sb2O3/SiO2作催化剂,催化合成乙酸异戊酯。考察了醇酸比、催化剂用量、反应温度与反应时间对酯化反应的影响。结果表明,乙酸异戊酯的最佳合成条件为:n(异戊醇)∶n(乙酸)=1.4∶1,催化剂用量为1.2 g,反应时间4 h,反应温度108~112℃,在此条件下酯化率可达95.7%。并用IR手段对产品进行了确证。     

对氨基苯磺酸催化合成乙酸异戊酯

采用对氨基苯磺酸为催化剂,对异戊醇与乙酸间的酯化反应进行了研究,考察了醇酸物质的量比、催化剂用量、反应时间对乙酸异戊酯收率的影响。结果表明,在回流条件下,当乙酸的加入量为0.156 mol,异戊醇的加入量为0.12 mol,即醇酸物质的量比为1∶1.3,催化剂用量为1.8 g,反应70 min时,乙酸异戊酯收率可达70.72%,且具有很高的纯度。     

对氨基苯磺酸催化合成乙酸异戊酯

采用对氨基苯磺酸为催化剂,对异戊醇与乙酸间的酯化反应进行了研究,考察了醇酸物质的量比、催化剂用量、反应时间对乙酸异戊酯收率的影响。结果表明,在回流条件下,当乙酸的加入量为0.156 mol,异戊醇的加入量为0.12 mol,即醇酸物质的量比为1∶1.3,催化剂用量为1.8 g,反应70 min时,乙酸异戊酯收率可达70.72%,且具有很高的纯度。     

磺化硅胶催化合成乙酸正丙酯的研究

磺化硅胶是一种以化学键键合而成,性能稳定的固体酸催化剂。实验以磺化硅胶为催化剂,乙酸和正丙醇为原料合成了乙酸正丙酯。以单因素法分别考察了酸醇摩尔比、反应时间、催化剂用量以及催化剂的重复使用次数对酯化率的影响。最佳合成条件为：n（乙酸）∶n（正丙醇）=1∶1,回流时间为60 min,催化剂用量为反应物总质量的1.2%,反应的酯化率可达93.4%,催化剂重复使用10次后的酯化率仍达81.1%。研究结果表明：磺化硅胶对乙酸正丙酯的合成具有良好的催化活性。     

磺化硅胶催化合成乙酸正丁酯的研究

磺化硅胶是一种以化学键键合而成,性能稳定的固体酸催化剂。本文以冰醋酸和正丁醇为原料,磺化硅胶为催化剂,合成了乙酸正丁酯,并获得了最佳合成条件:催化剂用量为反应物总质量的1.0%,n(乙酸)∶n(正丁醇)=1∶1.5,回流时间为45 min,乙酸正丁酯的酯化率可达98.5%,催化剂重复使用10次后的酯化率仍达81.3%。磺化硅胶对乙酸正丁酯的合成具有良好的催化活性。     

不同酸催化剂催化合成乙酸异戊酯的工艺研究

采用不同催化剂(浓硫酸和对甲苯磺酸)催化异戊醇与冰醋酸合成乙酸异戊酯。主要考察了醇酸摩尔比、反应时间及催化剂用量对乙酸异戊酯产率的影响,确定制备乙酸异戊酯的最佳反应条件,并对比研究了浓硫酸和对甲苯磺酸的催化效果。实验结果表明,对甲苯磺酸作催化剂性能明显高于浓硫酸,而且工艺简单、酯化产率高、条件温和、副反应少。其最佳反应条件为:异戊醇与冰醋酸的物质的量比为1.5:1、反应时间30 min、对甲苯磺酸用量0.5 g,在此最佳条件下乙酸异戊酯的产率可达到93.4%。     

Insect antifeedant properties of anthranoids from the genusVismia

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.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

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.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

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.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

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.     

2007～2008年世界塑料工业进展

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.     

2005～2006年国外塑料工业进展

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。