微波辐射四丁基氯化铵催化合成肉桂酸苄酯

本文研究了以肉桂酸钠和氯化苄为原料,四丁基氯化铵作催化剂,采用微波辐射技术,在常压下直接合成肉桂酸苄酯,以及催化剂用量、微波辐射功率和辐射时间对酯产率的影响。最适宜的反应条件为:当n(肉桂酸钠)∶n(氯化苄)=1∶1.2时,四丁基氯化铵的用量1.0g/0.05mol肉桂酸钠,微波功率300W,辐射25min,产率达84%以上。     

微波辐射十六烷基三甲基溴化铵催化合成肉桂酸苄酯

以肉桂酸钠和氯化苄为原料,十六烷基三甲基溴化铵作催化剂,采用微波辐射技术,在常压下直接合成肉桂酸苄酯,考察了催化剂用量、微波辐射功率和辐射时间对酯产率的影响。最适宜的反应条件为:当n(肉桂酸钠)∶n(氯化苄)=1∶1.2时,十六烷基三甲基溴化铵的用量1.0g,微波功率300W,辐射30min,产率达80%以上。     

微波辐射下肉桂酸苄酯的催化合成

以肉桂酸钠和氯化苄为原料,二乙胺作催化剂,采用微波辐射技术,在常压下直接合成肉桂酸苄酯,考查了催化剂用量、微波辐射功率和辐射时间对酯产率的影响。最适宜的反应条件为:当n(肉桂酸钠)∶n(氯化苄)=1∶3.4时,二乙胺的用量1.0mL,微波功率450W,辐射12min,产率达85%以上。     

相转移催化合成肉桂酸苄酯的研究

探索了以四丁基溴化铵（TBAB)为相转移催化剂催化合成肉桂酸苄酯,考察了催化剂的用量、反应温度、时间和物料配比等因素对反应的影响。实验结果表明：四丁基溴化铵是一个有效的催化剂,在最适宜的条件下。产物收率可达85．3％。最适宜的条件是：肉桂酸钠与氯化苄摩尔比为1：1．2,催化剂的用量为1．2g／0．05mol肉桂酸,反应时间3．0h,反应温度为95℃。产物的结构经IR,^1HNMR和MS表征。     

肉桂酸苄酯的合成研究

以十六烷基三甲基氯化铵为相转移催化剂催化合成肉桂酸苄酯,考察了催化剂、温度、时间和物料配比等因素对反应的影响。实验结果表明,十六烷基三甲基氯化铵是一种有效的催化剂,在最佳反应条件下,产物收率可迭86．0％。最佳反应条件是：n(肉桂酸钠)：n(氯化苄)为1：1.2,催化剂的用量为0．8g,反应时间3．0h,反应温度95℃。通过IR、^1HNMR和MS对产物结构进行了表征。     

催化剂对肉桂酸合成的影响

运用Perkin反应和Knovengel反应两种方法合成肉桂酸．并探讨了不同催化荆及其不同用量对产率的影响。实验证明．通过Perkin反应合成肉桂酸的最佳催化剂是碳酸钾．当n(苯甲醛)：n(碳酸钾)=1：1时．产率最高;通过Knovengel反应合成肉桂酸的最佳催化剂是吡啶．当n(笨甲醛)：n(吡啶)=1：1时．产率最高。     

微波辐射下Perkin反应合成肉桂酸

利用微波辐射在PEG-400活化下用苯甲醛和乙酸酐以Perkin法合成肉桂酸，最佳反应条件为：n(苯甲醛)：n(乙酸酐)：n(碳酸钾)：n(对苯二酚)：n(PEG-400)=1：3：1：0．02：0．02，辐射功率300W，副射时间20min，肉桂酸产率达65．3％。     

无溶剂微波辐射对甲氧基肉桂酸的合成

以对甲氧基苯甲醛为原料，醋酸铵为催化剂，采用微波辐射技术，经Knoevenagel反应，在无溶剂条件下合成了对甲氧基肉桂酸。先用L46(4^4)正交试验法确定了反应较合适的条件，然后用单因素试验法考察了酸醛摩尔比、醋酸铵用量、微波功率和辐射时间对反应的影响，得到反应的最佳条件：n(丙二酸)：n(醋酸铵)：n(醛)=1．2：1．0：1，微波功率400W，辐射时间7min。在此条件下产率为87．8％。产品结构经IR和H^1—NMR确证。     

无溶剂微波辐射醋酸铵催化合成肉桂酸

以苯甲醛为原料,醋酸铵为催化剂,经Knoevenagel反应,采用微波辐射技术,在无溶剂条件下合成了肉桂酸。先研究了不同功率和时间下缩合反应的产率,然后用单因素试验法考察了苯甲醛与丙二酸的摩尔比、催化剂用量对反应的影响,得到反应的最佳条件:n(丙二酸)∶n(醋酸铵)∶n(苯甲醛)=1.1∶1.0∶1,微波功率640W,反应时间6min,肉桂酸产率为84.5%。     

相转移催化合成肉桂酸苄酯的研究

探索了以十六烷基三甲基溴化铵为相转移催化剂催化合成肉桂酸苄酯的方法,考察了催化剂、温度、时间和物料配比等因素对反应的影响。实验结果表明：十六烷基三甲基溴化铵是一种有效的催化剂,在最适宜的条件下,产率可达91.7％。最适宜的条件是：肉桂酸钠与氯化苄摩尔比为1：1．3,催化剂的质量为0．6g,反应时间3．0h,反应温度为95℃。产物的结构经IR,^1H NMR和MS表征。     

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。