乙酰水杨酸微型化合成实验研究

探讨乙酰水杨酸微型化合成的最佳实验条件。以浓硫酸作催化剂,用乙酸酐与水杨酸进行酰化反应制备乙酰水杨酸,改变反应条件进行实验,重点考察了反应物摩尔数比、反应温度、反应时间及催化剂等条件对反应的影响。乙酰水杨酸微型化合成的最佳实验条件是:乙酸酐和水杨酸的摩尔数比为3∶1,反应温度60~80℃,以浓硫酸作催化剂,反应时间3~5 min。     

固体超强酸S_2O_8~(2-)/ZrO_2催化合成乙酰水杨酸

以S2O2-8/Zr O2固体超强酸为催化剂,水杨酸和乙酸酐为原料合成乙酰水杨酸。研究了原料配比、催化剂用量、反应时间、反应温度的影响,结果表明:固定水杨酸质量为7.0 g时,在水杨酸与乙酸酐的摩尔比为1∶2,催化剂用量为0.75 g,反应时间为45 min,反应温度为75℃的条件下,乙酰水杨酸的产率为86.8%。催化剂重复使用5次产率还能够达到75.2%。     

2-乙酰噻吩的合成

以噻吩和乙酸酐为原料,噻吩与乙酸酐摩尔比为1∶1.2,在催化剂作用下合成2-乙酰噻吩。催化剂分别为碘、磷酸、磷钨酸时,收率分别为76.9%、77.4%、67.8%。产物经IR和沸点表征为目标产物。     

磷钨酸催化合成乙酰水杨酸的研究

以水杨酸和乙酸酐为原料,磷钨酸为催化剂催化合成乙酰水杨酸。考察了催化剂用量、反应物料配比、反应时间、温度等因素对反应的影响。结果表明,最佳工艺条件为:水杨酸∶乙酸酐∶磷钨酸的物质的量比为1∶2.5∶0.002 4,反应时间25 min,反应温度76~80℃。该法具有反应条件温和、催化剂用量小、酐醇比小、无污染、后处理简单等优点。     

尿素催化合成乙酰水杨酸

以水杨酸和乙酸酐为原料,采用尿素作催化剂合成乙酰水杨酸。考察了温度、尿素用量、n(水杨酸)∶n(乙酸酐)和时间对反应的影响。正交试验结果表明,较适宜的反应条件为:n(水杨酸)∶n(乙酸酐)=1∶3,尿素用量为水杨酸质量的5%,反应温度85℃,反应时间60 min,此条件下,乙酰水杨酸收率达94.06%。     

对甲苯磺酸催化合成乙酸芳樟酯

以芳樟醇和乙酸酐为原料,对甲苯磺酸为催化剂,合成了乙酸芳樟酯。考察了反应温度、反应时间、催化剂用量和原料配比等因素对反应结果的影响。当n(芳樟醇)∶n(乙酸酐)=1∶2,反应温度15℃,催化剂用量为醇酐总质量的0 2%,反应时间150min时,乙酸芳樟酯的收率可达73 6%。与现有工艺相比,采用对甲苯磺酸为催化剂,具有反应温度低、反应时间短、不使用夹带剂和乙酸芳樟酯的收率比较高等优点。     

对甲苯磺酸催化合成乙酰水杨酸的研究

以水杨酸和乙酸酐为原料，采用对甲苯磺酸作催化剂合成了乙酰水杨酸，考察了影响反应的因素。实验结果表明酰化反应的优化条件为水杨酸：乙酸酐：对甲苯磺酸摩尔比为1：2：0．0153，反应20min，反应温度81～85℃，产率达94．44％。     

微波催化合成乙酸异丁酯

在微波作用下 ,分别以浓H2 SO4、对甲苯磺酸、CuCl2 ·2H2 O为催化剂 ,以乙酸酐和异丁醇为原料合成乙酸异丁酯。最佳反应条件为 :乙酸酐和异丁醇的摩尔比为 1.2 :1,反应时间为 4min ,催化剂种类为对甲苯磺酸 ,微波功率为 2 10W ,转化率为 91.4 %。     

超声波辅助强酸性阳离子交换树脂催化合成乙酰水杨酸的研究

用强酸性阳离子交换树脂为催化剂,以水杨酸和乙酸酐为反应原料,通过超声波辐射加热快速合成了乙酰水杨酸。最佳合成条件为:原料摩尔比乙酸酐∶水杨酸=3∶1,超声频率59 Hz,辐射时间25 min,反应温度70~75℃,催化剂用量0.5 g,产率达到92%,催化剂重复5次后仍然达到很高的产率。该法反应时间短,操作简单,催化剂可重复利用,环境友好,节约能源。     

SO4^2-／TiO2固体超强酸催化合成乙酰水杨酸

以水杨酸和乙酸酐为原料在SO4^2-／TiO2固体超强酸催化下合成了乙酰水杨酸。考察了催化剂的焙烧温度、反应时间、反应温度、原料配比、催化剂用量等对反应的影响以及催化剂的稳定性。确定最佳反应条件为：催化剂的焙烧温度500℃、反应温度90℃、反应时间40min、n（乙酸酐）：n（水杨酸）=2．0：1、催化剂用量1．0g,此时乙酰水杨酸的收率可达77．8％。SO4^2-／TiO2固体超强酸催化荆制备简单、催化活性高、重复使用性好、后处理简便、无三废污染,符合节能环保的绿色催化发展趋势。     

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。