微波辐射加热法合成柠檬酸三异戊酯的研究

以柠檬酸和异戊醇为原料采用微波辐射法合成了柠檬酸三异戊酯.考察了催化剂、带水剂、反应时间、物料比等因素对反应的影响.通过正交实验,得到最佳的工艺条件如下:柠檬酸7.7 g,异戊醇21.7 mL(酸醇摩尔比为1∶5);一水合硫酸氢钠作催化剂,用量为1.0 g(为原料总质量的4%);带水剂为二甲苯,用量为25 mL;微波辐射时间为15 min.该条件下的反应速率约是常规加热法的16倍,产品平均收率为83.2%(平均酯化率为95.1%).通过元素分析和红外光谱对产品的结构进行了初步表征.     

柴油十六烷值改进剂草酸二异戊酯的合成

本采用以草酸和异戊醇为原料,硫酸锌为催化剂,环己烷为带水剂,合成了新型柴油十六烷值改进剂草酸二异戊酯。通过单因素试验,研究了酸醇摩尔比、反应时间、催化剂用量和带水剂用量对酯化反应的影响,采用正交实验考察了各因素对酯收率的影响。结果表明:当反应温度为回流温度(85~120℃),n(草酸):n(异戊醇)=1:2.8,催化剂用量为草酸质量的8%,带水剂用量为10mL/0.1mol草酸,反应时间90min时,草酸二异戊酯的收率为90.3%。     

微波辅助合成丁酸环己酯

探讨了在微波辐射下以丁酸和环己醇为原料直接酯化合成丁酸环己酯的方法.系统考察了催化剂、物料比、反应时间、带水剂用量等因素对酯化反应的影响.结果表明适宜的合成条件为:选用硫酸氢钠作催化剂,用量为反应物总质量的3%(2.0 g),酸醇摩尔比为1∶1.7,微波辐射时间为10 min,带水剂二甲苯用量为50 mL.此时反应的酯化率为91.8%、酯收率为90.1%,其反应速率约是常规加热法反应速率的12倍.     

微波辐射丝光沸石催化合成氯乙酸异戊酯

研究了微波辐射作用下丝光沸石催化氯乙酸与异戊醇的酯化反应。通过正交实验得出微波功率、加热时间、催化剂用量等因素对酯化反应影响的重要性次序为:微波功率>醇酸物质的量比(醇酸比)>加热时间>催化剂用量。最佳工艺条件为:微波功率585W,加热时间为25min,催化剂用量为2.0%,醇酸比为1.5∶1,此条件下氯乙酸异戊酯的产率为93.2%。对比实验结果表明,微波辐射加热法合成氯乙酸异戊酯的反应速度至少是常规加热法的14倍。常温X射线粉末衍射(XRD)分析表明,微波辐射对沸石催化剂的晶相结构无破坏作用。     

对甲苯磺酸催化合成草酸二异戊酯的研究

以草酸和异戊醇为原料,对甲苯磺酸为催化剂,环己烷为带水剂,合成了新型柴油十六烷值改进剂草酸二异戊酯。考察了酸醇的物质的量比、反应时间、催化剂用量和带水剂用量等因素对酯收率的影响。结果表明:当反应温度为回流温度(85~100℃),n(草酸)∶n(异戊醇)=1∶3.5,催化剂用量为草酸质量的1.5%,带水剂用量为10mL/0.1 mol草酸,反应时间110~120 m in时,草酸二异戊酯的收率大于88%。与现有工艺相比,采用对甲苯磺酸为催化剂,环己烷为带水剂,具有反应温度低、反应时间短、带水剂的毒性较小、草酸二异戊酯的收率和纯度较高等优点。产物经红外光谱和气相色谱分析,证明确为草酸二异戊酯且纯度大于98%。     

微波辐射磷钨酸催化合成环己酮1,2-丙二醇缩酮

在微波辐射下,以磷钨酸为催化剂,以环己酮和1,2-丙二醇为原料合成了环己酮1,2-丙二醇缩酮.研究了反应物投料比、微波辐射功率、微波辐射时间、催化剂用量、带水剂用量等因素对产品收率的影响.确定了最佳反应条件为:环己酮0.2 mol,n(环己酮)∶n(1,2-丙二醇)=1∶1.5,催化剂用量为反应物总质量的0.50%,微波辐射功率600 W,辐射时间16 min,带水剂(环己烷)用量15 mL.在此条件下,环己酮1,2-丙二醇缩酮的产率可达82.0%.     

氨基磺酸催化合成草酸二异戊酯

以氨基磺酸为催化剂,环己烷为带水剂,对草酸与异戊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、反应时间对草酸二异戊酯收率的影响。结果表明,氨基磺酸有着良好的催化活性,在草酸用量0.1 mol,n(异戊醇)∶n(草酸)=3.5∶1,催化剂用量为反应物总质量的1.5%,环己烷用量16 mL,回流反应60 min条件下,草酸二异戊酯收率可达86.5%,催化剂重复使用5次仍保持较高活性。     

硼酸三丁酯的合成

以正丁醇和硼酸为原料采用微波辐射法合成硼酸三丁酯,考察了催化剂、带水剂、反应时间和反应温度对反应的影响。通过试验得到适宜工艺条件(试验室)为:硼酸用量为0.10mol、n(正丁醇)/n(硼酸)为5.2(正丁醇兼作带水剂)、m(NaHSO4催化剂)/m(原料总量)为2.2%和微波辐射时间为13.0min。该条件下产品平均收率为87.4%,反应速率(以酯的收率计)约是常规加热法的18～20倍。通过元素和红外光谱分析对产品进行了物性及结构表征。     

微波辐射磷钨酸催化合成环己酮1,2-丙二醇缩酮

在微波辐射下,以磷钨酸为催化剂,对以环己酮和1,2-丙二醇为原料合成环己酮1,2-丙二醇缩酮进行了研究.较系统的研究了反应物投料比、微波辐射功率、微波辐射时间、催化剂用量、带水剂用量诸因素对产品收率的影响.最佳反应条件为:环己酮为0.2mol,n(环己酮):n(1,2-丙二醇)=1.0:1.5,微波辐射功率600W,辐射时间16min,催化剂用量为反应物总质量的0.5%,带水剂(环己烷)15mL.在此条件下,环己酮1,2-丙二醇缩酮的产率可达82.0%.     

微波辐射四氯化锡催化合成草酸二丁酯的研究

本文研究了以SnCl4为催化剂,以草酸和正丁醇为原料,在微波辐射下合成草酸二丁酯的方法.通过实验得出最佳反应条件为:醇酸摩尔比为3.5:1,催化剂用量为总投料量的2%,微波辐射功率为480W,在此条件下取得了较好的收率.     

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。