柠檬酸三辛酯的催化合成研究

以柠檬酸和异辛醇为原料,无机盐硫酸氢钾为催化剂,非均相酯化反应生成柠檬酸三辛酯(TOC),考察了原料配比、反应温度、反应时间、催化剂用量等因素对合成反应的影响。实验表明,该无机盐催化剂具有较高的催化活性,其最佳工艺条件为:n(异辛醇)∶n(柠檬酸)=5.0,催化剂用量为反应物总质量的3%,150℃条件下反应2 h,酯化率达到96%以上;而且硫酸氢钾有较好的重复使用性,使用6次后酯化率仍达90.85%,且便于与产物分离,回收利用效果好,对设备腐蚀和环境污染都较小。     

硫酸氢钾催化合成草酸二丁酯

以硫酸氢钾为催化剂,环己烷为带水剂,对草酸与正丁醇之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、带水剂加入量、反应时间对草酸二丁酯收率的影响。结果表明,硫酸氢钾有着良好的催化活性,在草酸用量0.1 mol,n(正丁醇)∶n(草酸)=3.0∶1,催化剂用量为反应物总质量的1.0%,环己烷用量16 mL,回流反应30 min条件下,草酸二丁酯收率可达82.8%,催化剂重复使用6次仍保持较高活性。     

硫酸氢钾催化合成肉桂酸异丙酯

用硫酸氢钾催化肉桂酸与异丙醇的酯化反应,合成了肉桂酸异丙酯.研究结果表明,硫酸氢钾具有较高的催化活性.考察了肉桂酸/异丙醇摩尔比、催化剂用量、反应时间对酯产率的影响,以及催化剂的重复使用性能.在典型反应条件(肉桂酸/异丙醇/硫酸氢钾的摩尔比=1∶5.5∶0.48,回流3 h)下,所得肉桂酸异丙酯的产率为72.0%.该催化剂易于回收且可重复使用.     

十二烷基苯磺酸催化合成乙酸异戊酯的研究

以异戊醇和乙酸为原料,十二烷基苯磺酸(DBSA)为催化剂,采用正交试验方法合成了乙酸异戊酯.研究了物料比、酯化时间、酯化温度和催化剂用量对酯化率的影响.确定了最佳的工艺条件为:n(酸)∶n(醇)=1∶4、催化剂用量为酸物质的量的5％、反应温度45℃、反应时间为4h,其酯化率最高可达81.57％.     

硫酸氢钾催化合成肉桂酸异丁酯

应用硫酸氢钾催化肉桂酸与异丁醇的酯化反应,合成了肉桂酸异丁酯.研究结果表明,硫酸氢钾具有较高的催化活性.考察了肉桂酸/异丁醇摩尔比、催化剂用量、反应时间对酯产率的影响,以及催化剂的重复使用性能.在典型反应条件(肉桂酸/异丁醇/硫酸氢钾的摩尔比=1∶10∶0.37,回流3 h)下,所得肉桂酸异丁酯的产率为87.0%.该催化剂易于回收且可重复使用.     

SO42-/WO3-ZrO2催化合成乙酸丁酯

制备了硫酸促进型酯化催化剂SO42-/WO3-ZrO2,考察了WO3含量、焙烧温度和焙烧时间等对酯化率的影响。结果表明催化剂适宜制备条件为：WO3含量10%,300℃焙烧2h;将其用于催化乙酸与正丁醇的酯化反应合成了乙酸丁酯,反应条件为：乙酸0.2mol,催化剂0.75g,n（正丁醇）∶n（乙酸）=1.8∶1,反应时间30min,酯化率可达98.2%。     

硅胶固载氧化镓非均相催化合成乙酸丁酯

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%。     

铁钾盐加合物催化合成乙酸丙酯

以铁钾盐加合物为催化剂,合成了乙酸丙酯。考察了铁钾盐加合物的催化活性,研究了酸醇量比,反应时间,催化剂用量等对酯化率的影响。结果表明,铁钾盐加合物是合成乙酸丙酯的理想催化剂,其较优反应条件为:以0.1 mol乙酸为基准,n(乙酸)∶n(丙醇)=1∶1.3,催化剂用量为反应物总质量的2%(乙酸与丙醇总质量的质量分数),10 mL环己烷带水剂,回流反应3h,乙酸的酯化率可达98.88%。     

离子液体催化合成乙酸苄酯

以硫酸氢根甲基咪唑盐[Hmim]HSO_4离子液体为催化剂,乙酸和苯甲醇为原材料通过催化反应来合成乙酸苄酯,同时还讨论了以浓硫酸作为催化剂合成乙酸苄酯的方法。通过各个不同条件的实验,涉及的可变因素有酸醇物质的量比、催化剂用量、反应时间、反应温度等。实验结果表明,硫酸氢根甲基咪唑盐[Hmim]HSO_4对合成乙酸苄酯有着良好的催化活性,而且对其合成工艺进行了优化,确定最佳反应条件为:酸醇的摩尔比为1.4∶1、催化剂用量1%、反应温度110℃、加热回流1 h。在此条件下,乙酸苄酯的酯化率达96%。     

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.     

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。