食用香料丁酸己酯合成研究

以钨硅酸为催化剂,通过丁酸和己醇反应合成了丁酸己酯,探讨了醇酸物质的量比、催化剂用量及反应时间对酯化率的影响.实验结果表明:钨硅酸具有良好的催化活性,在醇酸物质的量比为1.2:1、催化剂用量为0.2g/0.1mol丁酸、带水剂(环己烷)8mL、反应温度112～126℃、反应时间1h时,酯化率可达99.1%.     

微波辐射纳米Y2O3催化合成乙酸龙葵酯

以乙酸和龙葵醇为原料,以纳米Y2Q为催化剂,利用微波技术合成了乙酸龙葵酯.探讨了微波辐射功率、辐射时间、醇酸摩尔比及催化剂用量等对酯化反应的影响.实验结果表明,较佳的反应条件为:在龙葵醇用量为0.1 mol时,n(龙葵醇):n(乙酸)=1:1.8,纳米Y2O3催化剂用量为反应物总质量的1.1%.带水剂环已烷10 mL,微波功率为350 W,辐射时间为10 min,乙酸龙葵酯收率可达96.5%.催化剂重复使用6次仍保持较高活性.     

微波辐射纳米氧化钐催化合成草酸二丁酯

采用微波辐射技术,以纳米氧化钐为酯化反应催化剂合成草酸二丁酯。利用正交实验设计和单因素实验考察了微波辐射功率、微波辐射时间、催化剂用量、醇酸摩尔比等因素对酯化反应的影响。结果表明,纳米氧化钐催化剂在草酸二丁酯的合成中显示出良好的催化性能,而且该方法具有操作简便、反应速率快、节约能源等优点。在草酸用量为0.2mol、微波输出功率350W、辐射时间12min、催化剂用量为反应物总质量的1.0%、醇酸摩尔为4.0∶1的优化条件下,酯化率可达98.3%。     

杂多钨酸催化合成丁酸酯

以杂多钨酸作催化剂,对丁酸与丁醇的液相酯化反应进行了研究,考察了催化剂用量、反应时间、醇酸比、带水剂用量四个因素,得到了合成该酯的适宜条件,并对杂多钨酸催化合成丁酸酯也进行了研究。     

强酸性阳离子交换树脂催化合成丁酸己酯的研究

以丁酸、正己醇为原料，直接酯化合成丁酸己酯，分别研究了反应温度、反应时间、原料配比、带水剂、催化剂用量等条件对合成反应的影响，确定了最佳工艺条件。该方法合成丁酸己酯的最佳工艺条件是：反应温度120℃、反应时间3．5h、n（正己醇）：n（丁酸）为1．2、催化剂用量为2．32％、带水剂环己烷为15mL（丁酸为0．2mol的情况下）。丁酸己酯的收率达到95．86％。催化剂不经处理可循环使用多次。该催化剂具有价廉易得、催化活性好、不腐蚀设备、无环境污染等优点。     

微波辐射SiO2负载磷钨酸催化合成丙酸苄酯

研究了微波辐射下,用SiO2负载磷钨酸催化剂直接催化合成丙酸苄酯的反应,考察了影响酯化收率的因素。其优化反应条件为催化剂用量0.5g(磷钨酸负载量20.2%),微波辐射功率450W、反应时间4.0min,n(丙酸)/n(苯甲醇丙酸)=1∶1,带水剂(环己烷)用量5mL,丙酸苄酯收率达83.4%。结果表明:相同条件下微波辐射-SiO2负载磷钨酸催化剂与常规加热-SiO2负载磷钨酸催化剂相比之下加快反应速度45倍,催化剂可重复使用。     

丁酸异戊酯合成工艺研究

以环己烷为带水剂,采用微波辐射技术,在对甲苯磺酸的催化下,快速合成了丁酸异戊酯。探讨了原料配比、反应时间、催化剂用量、微波功率等参数对酯化率的影响。在适宜工艺条件下,酯化率可达99％以上。     

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.     

微波辐射硫酸铁催化合成丙二酸二乙酯的研究

研究了利用微波辐射技术,在硫酸铁的催化下以丙二酸和无水乙醇为原料合成丙二酸二乙酯的反应,探讨了原料配比、反应时间、催化剂用量、带水剂、反应温度等对酯化率的影响。通过实验确定了最佳反应条件：n（乙醇）∶n（丙二酸）为3∶1,催化剂硫酸铁用量为1.0g,带水剂环己烷用量为20mL,微波辐射时间为10min,结果表明：该反应条件温和,方法简便,酯化率可达72.1%。利用折光率、红外光谱分析等对产品进行了物性、组成和结构表征。     

微波辐射增塑剂柠檬酸三辛酯的催化合成研究

以柠檬酸和正辛醇为原料采用强酸性阳离子交换树脂作为催化剂,同时应用微波辐射技术合成了柠檬酸三辛酯。最佳条件为微波功率600 W、醇酸摩尔比为5、反应时间为35 m in、反应的温度为180℃、催化剂用量为0.6 g。在最佳反应条件下不采用带水剂酯化率可达95%。实验表明：此法反应时间短、酯化率高、催化剂活性高且可重复使用、操作简单、无污染、绿色环保。     

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。