Perkin反应合成肉桂酸

以无水碳酸钾为催化荆，PEG-400为相转移催化剂，对苯二酚为阻聚剂．通过Perkin反应合成肉桂酸，研究了物料比、催化刺用量、PEG-400用量、对苯二酚用量、回流时间对产品产率的影响。最佳反应条件是n(苯甲醛)：n(乙酸酐)：n(碳酸钾)：n(PEG-400)：n(对苯二酚)=1：3：1．1：0．03：0．02．回流溢度180℃时．回流时间1．5h，肉桂酸产率呵达82.4％。     

Perkin反应合成肉桂酸

以无水碳酸钾为碱催化剂,PEG-400为相转移催化剂,对羟基苯甲醚为阻聚剂,通过Perkin反应合成肉桂酸,研究了各物料比、回流时间对产品产率的影响.最佳反应条件是n(苯甲醛)∶n(乙酸酐)∶n(碳酸钾)∶n(PEG-400)∶n(对羟基苯甲醚)=1∶3∶1.1∶0.02∶0.02,回流温度180℃,回流时间1.5h,肉桂酸产率可达75%.     

肉桂酸合成的正交试验设计

以苯甲醛和乙酸酐为原料,在催化剂及加热条件下进行缩合反应来合成肉桂酸。用正交试验法研究确定了合成肉桂酸的较佳反应条件为：催化剂采用无水碳酸钾,用量为0．02mol,醛酐物质的量比1：1．5,反应时间105min,肉桂酸收率可达68％。     

KF/γ-Al2O3型固体超强碱催化合成肉桂酸的研究

苯甲醛与乙酐的Perkin反应合成肉桂酸，首次采用KF/γ-Al2O3固体超强碱催化剂，降低了反应温度，明显缩短了反应时间，最佳反应条件为n(苯甲醛)：n(乙酐)=1．0：3．0，反应时间1．5h，反应温度160℃，催化剂用量为苯甲醛质量的0．5％，所得的肉桂酸的产率可达81％以上。该催化剂具有较高的催化活性，易于回收，可重复使用5次以上。     

相转移催化合成肉桂酸

以苄基三乙基氯化铵为相转移催化剂,K2CO3为催化剂,通过Pinker反应合成了肉桂酸。在回流条件下,以苄基三乙基氯化铵为相转移催化剂时,n(苯甲醛)∶n(乙酸酐)∶n(碳酸钾)∶n(苄基三乙基氯化铵)=1∶3∶1∶0.03,回流90min,肉桂酸的产率可达到78.5%。     

高产率肉桂酸的绿色合成研究

在微波辐射条件下,以无水碳酸钾为碱催化剂,以聚乙二醇-400(PEG-400)为相转移催化剂,加入自制吸波材料(MA)通过Perkin法合成肉桂酸。考察了MA的加入量、PEG-400的用量以及微波辐射功率和时间对肉桂酸产率的影响。利用熔点测定及傅里叶红外光谱分析(FTIR)对产物结构进行了确证,确定最佳反应条件为:MA用量为苯甲醛质量的4.8%,PEG-400用量为苯甲醛质量的7.5%,130 W功率微波下反应6 min,此时肉桂酸的产率达到94.3%。     

高产率肉桂酸的绿色合成研究

在微波辐射条件下,以无水碳酸钾为碱催化剂,以聚乙二醇-400(PEG-400)为相转移催化剂,加入自制吸波材料(MA)通过Perkin法合成肉桂酸。考察了MA的加入量、PEG-400的用量以及微波辐射功率和时间对肉桂酸产率的影响。利用熔点测定及傅里叶红外光谱分析(FTIR)对产物结构进行了确证,确定最佳反应条件为:MA用量为苯甲醛质量的4.8%,PEG-400用量为苯甲醛质量的7.5%,130 W功率微波下反应6 min,此时肉桂酸的产率达到94.3%。     

微波快速合成肉桂酸

以苯甲醛、乙酸酐为原料、KF／K2CO3为催化剂微波快速辐射,并用正交试验优选出最佳合成工艺条件：n(苯甲醛)：n(乙酸酐)：n(KF／K2CO3)=1：3：1.45,微波功率650W,反应6min,产率可达76.09％。     

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。     

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。     

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.     

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。     

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.