苯甲酰甲酸乙酯的合成及工艺优化研究

苯甲酰甲酸乙酯是合成除草剂苯嗪草酮的关键中间体。针对苯甲酰甲酸容易在强酸性、高温和强氧化剂条件下脱羰基、脱羟基和氧化分解等问题,采用工业级苯和工业级三氯乙醛为起始原料,合成了较高收率的苯甲酰甲酸乙酯。首先在过量苯与三氯乙醛体系中,用无水三氯化铝催化合成了2,2,2-三氯-1-苯基乙醇;2,2,2-三氯-1-苯基乙醇经过碱解得到2-羟基-2-苯基乙酸;然后将2-羟基-2-苯基乙酸与乙醇酯化,生成2-羟基-2-苯基乙酸乙酯;再通过NaOH-H_2O_2室温氧化2-羟基-2-苯基乙酸乙酯,得到苯甲酰甲酸乙酯。经高效液相色谱法(HPLC)测定,苯甲酰甲酸乙酯的质量分数为98%以上,以三氯乙醛计总收率可达72.12%。     

一种肉桂酸及其衍生物合成新方法研究

以苯甲醛为原料,与磷酰基乙酸三乙酯在氢化钠存在下反应制备肉桂酸乙酯,后通过水解制备肉桂酸,总收率95%。考察了温度、溶剂、反应时间、物料摩尔比对肉桂酸乙酯收率的影响。结果表明,最佳反应条件为室温下,以二氯甲烷为溶剂,反应2 h,苯甲醛、磷酰基乙酸三乙酯、氢化钠摩尔比为1∶1.5∶1.5,该步反应收率97%,水解反应收率98%。利用该优化方案合成了一系列肉桂酸衍生物,收率均在92%以上,结构通过质谱、核磁鉴定正确。     

一种肉桂酸及其衍生物合成新方法研究

以苯甲醛为原料,与磷酰基乙酸三乙酯在氢化钠存在下反应制备肉桂酸乙酯,后通过水解制备肉桂酸,总收率95%。考察了温度、溶剂、反应时间、物料摩尔比对肉桂酸乙酯收率的影响。结果表明,最佳反应条件为室温下,以二氯甲烷为溶剂,反应2 h,苯甲醛、磷酰基乙酸三乙酯、氢化钠摩尔比为1∶1.5∶1.5,该步反应收率97%,水解反应收率98%。利用该优化方案合成了一系列肉桂酸衍生物,收率均在92%以上,结构通过质谱、核磁鉴定正确。     

2-苯基-1,3-丙二醇合成工艺的研究

以苯乙酸乙酯、甲酸乙酯、甲醇钠、硼氢化钠为原料合成标题化合物,该方法操作方便,总收率达80.1%,产品纯度高达99.5%.同时研究了溶剂对第二步还原反应的影响,研究表明,乙醇作溶剂时收率较高,成本较低.通过IR和 ~1HNMR 分析确定了目标化合物的结构.     

氯甲酸-β-氯乙酯的合成

报道了氯甲酸 β 氯乙酯的两种合成方法,并对光气法进行了研究。其最佳反应条件为:温度为30℃,反应时间为2～2.5h,氯乙醇与光气摩尔比为1∶3。在上述条件下,氯甲酸 β 氯乙酯收率可达88.3%。     

己二酸二乙酯的合成

以对甲苯磺酸为催化剂,由乙醇和己二酸通过酯化反应合成了己二酸二乙酯。研究了反应时间、不同带水剂和不同乙醇对己二酸二乙酯产率的影响。并用折光率、红外光谱对己二酸二乙酯进行表征。其最佳反应条件为：酸醇摩尔比为1∶6,对甲苯磺酸用量为0.40 g,苯用量为20 mL。收率为70.8%。     

壳聚糖硫酸盐催化合成丙二酸二乙酯

研究了以壳聚糖硫酸盐为非均相催化剂,丙二酸与乙醇为原料酯化合成丙二酸二乙酯的新工艺,用正交试验确定了反应的较佳工艺条件为:丙二酸的加入量为0.1 mol时,醇酸摩尔比为3.0:1.0,催化剂用量为反应物总质量的2.0%,带水剂苯15 mL,回流反应时间2.0 h,酯化率可达97%以上.结果表明,该催化剂用于合成丙二酸二乙酯具有良好的催化活性和重复使用性.     

合成低级脂肪酸乙酯方法的改进

本文采用了以硫酸锆为催化剂,以硫酸镁为脱水剂将乙醇和低级脂肪酸进行酯化反应,以制备低级脂肪酸乙酯。采用本法合成低级脂肪酸乙酯收率在83～88%,产品纯度在98%以上。该法的优点在于催化剂和脱水剂可以循环利用,而且整个工艺过程无污染。     

2-乙氧基丙烯绿色合成技术的研究

以酸性阳离子交换树脂为催化剂在无溶剂的条件下,采用丙酮和原甲酸三乙酯缩合来制备丙酮缩二乙醇,通过正交实验和单因素实验得到适宜的反应条件为:反应温度15℃、保温时间10h、催化剂用量1:80(m/m)、原料配比n(丙酮):n(原甲酸三乙酸)=1.0:1、催化剂用量m(催化剂):m(原甲酸三乙酸)=1:100。再以氯化铵为催化剂采用反应精馏技术由丙酮缩二乙醇制备了2-乙氧基丙烯,考察了回流比对2-乙氧基丙烯收率的影响,得到适宜的回流比为8。在适宜的操作条件下,2-乙氧基丙烯单程总收率达77.2%。该技术具有所需设备投资和能耗较低、流程简单且对环境友好的优点,是一种可行的绿色合成技术。     

精馏法合成乳酸乙酯的研究

采用带分水器的精馏装置 ,使乳酸酯化的原有脱水 -酯化两步过程 ,能在该装置上一步进行。通过正交试验 ,考察了乙醇的用量、催化剂的用量、带水剂的用量三个因素对乳酸乙酯收率的影响。确定了最佳的配比 ,并由验证实验得到证明 ,脱水 -酯化反应在 2h基本完成 ,乳酸乙酯的收率可达到 96 %以上     

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。