3,5,6-三氯吡啶-2-醇钠在超(近)临界水中的稳定性

3,5,6-三氯吡啶-2-醇钠(STCP)热稳定性的研究对于认识2,3,5,6.四氯吡啶(TCP")水解制取STCP过程和STCP废水的处理具有重要的实际意义.在管式反应器中考察了温度、压力、停留时间和物料配比对STCP稳定性及其降解产物的影响.结果表明,当温度低于280℃时,STCP具有良好的稳定性;随着反应温度的升高、压力的增大和停留时间的延长,其稳定性降低.降解产物在525 nm处出现的特征峰是STCP的异构体吡啶酮类化合物引起的.此外,在加压条件下研究了反应温度、压力、时间和原料配比对TCP水解的影响,其中反应温度是决定水解反应的关键因素,TCP与NaOH摩尔比为1:4时,140℃下反应3 h,收率达95%以上,纯度为99%.     

2,3,5,6-四氯吡啶在乙二醇中水解动力学

以乙二醇为溶剂,研究了2,3,5,6-四氯吡啶(TcP)水解生成3,5,6-三氯吡啶-2-醇钠(STCP)的反应动力学特性,考察了温度和水分的影响.结果表明TCP的水解速率受温度的影响很明显,加入少量的水有利于提高氢氧化钠的电离度,提高反应速率.通过对数据的拟合,建立了乙二醇中TCP水解的动力学模型.与实验数据相比,模型计算结果的相对标准偏差小于±10%.模型分析表明TCP水解反应的表脱活化能为(149.16±3.42)10/mol.     

3，5，6-三氯吡啶-2-酚的合成

以五氯吡啶为原料,通过锌粉还原制备出中间产物2,3,5,6-四氯吡啶,再由2,3,5,6-四氯吡啶水解,制备出农药中间体3,5,6-三氯吡啶-2-酚。水解反应的最佳反应条件为:反应温度为95~100℃、反应时间为20h,收率可达到95%。两步反应总收率可以达到90%。     

2-乙烯基吡啶的合成研究

研究了以2-羟乙基吡啶为原料,经脱水反应合成2-乙烯基吡啶的实验方法。探讨了反应过程中催化剂、反应温度、反应时间等影响因素,得出了适宜的反应条件:在固体氢氧化钾催化下,n(氢氧化钾)∶n(2-羟乙基吡啶)=0.2∶1,反应时间1~1.5 h,反应温度100℃,收率达到85%以上,产品纯度大于98%。反应过程催化剂采用循环套用的方法,减少了原料消耗,降低了生产成本,具有较强额实际生产意义。     

2-(2-溴-9-苯基-9H-芴-9-基)吡啶的合成研究

以2-溴吡啶为初始原料,经格氏反应、亲核取代反应和傅克反应合成了2-(2-溴-9-苯基-9H-芴-9-基)吡啶,总收率为46.3%,通过1H NMR、13C NMR、 MS和IR表征了化合物的结构;研究了傅克反应中反应温度和反应时间对目标化合物收率的影响,得出优化反应条件:反应温度为5℃,反应时间为5h,优化条件下,傅克反应的收率为71.1%。     

三步法制备2-吡啶甲醇的研究

研究以2-甲基吡啶等为原料,经过氧化、酰化重排、水解反应合成2-吡啶甲醇。探讨了反应时间、反应温度、原料配比等对氧化反应过程的影响,氧化反应的最佳工艺条件是:反应时间,15h;反应温度,75℃;原料摩尔配比为n(2-甲基吡啶)∶n(冰乙酸)∶n(双氧水)=1∶4∶3,2-甲基吡啶N-氧化物的收率为88.12%。对2-甲基吡啶N-氧化物进行酰化重排和水解反应,并对最终产物进行FT IR、1 H NMR表征和HPLC检测,结果表明:最终产物为2-吡啶甲醇,纯度为98.94%。     

2-氨基-5-氟吡啶的合成

2-氨基-5-氟吡啶是合成肽脱甲酰基酶抑制剂LBM415的重要中间体.以2-氨基吡啶为原料,经过混酸硝化,氨基乙酰化保护,硝基还原,重氮化及席曼反应引入氟原子以及水解脱乙酰基等步骤合成2-氨基-5-氟吡啶.该路线简化了实验操作,避免了文献报道的在原料2-氯-5-氨基吡啶的合成、中间产物的分离和最终产品的纯化过程中出现的收率低以及纯度不高的问题.各步反应比较适宜的工艺条件(反应温度,反应时间,摩尔收率)分别为,硝化反应:45℃,2 h,41%;氨基保护:回流,1 h,96.3%;硝基还原:回流,1 h,90%;重氮化:-5～0℃,2 h,81.4%;席曼反应:130℃,0.5 h,乙酰基水解:回流,2.5 h,两步反应总收率为51.6%.产物熔点与文献报道一致,并通过1H-NMR和IR确认了2-氨基-5-氟吡啶的结构.     

吡啶气相光氯化合成2-氯吡啶工艺优化

采用吡啶为原料、水为稀释剂,在常压下进行吡啶气相光氯化合成2-氯吡啶,考察了不同波长的光源、反应温度、原料配比、空时等对吡啶转化率和2-氯吡啶收率的影响.实验发现,用蓝光作为光源比采用紫外光效果更好,得到的最佳反应条件为反应温度170 ℃～180 ℃,n(Cl2)n(C6H5N)为(1.5～2)∶1,空时100S,吡啶的转化率可达70%以上,2-氯吡啶的选择性在95%左右.     

2-氨基-3-甲基吡啶的合成新方法

以过氧化氢为氧化剂,在稀碱条件下将2-氰基-3-甲基吡啶不完全水解形成3-甲基-2-吡啶甲酰胺,然后用新制备的次溴酸钠进行霍夫曼降解,获得标题化合物2-氨基-3-甲基吡啶。比较适宜的反应条件(反应温度,氢氧化钠浓度,反应时间)水解反应:50°C,5%,3.5 h,H2O2浓度为10%;霍夫曼降解反应:60°C,12%,0.5 h。摩尔总收率达74%,并通过GC-MSI、R、和1H NMR确证结构。     

2-羟基吡啶合成研究

以2-氨基吡啶为原料,在20%(质量分数)的硫酸溶液中,通过滴加过量的10%(质量分数)的亚硝酸钠,在0~5℃左右进行重氮化反应,重氮液在Na2CO3溶液中水解、中和后合成2-羟基吡啶,采用结晶和重结晶的方法,得到含量为98%以上的2-羟基吡啶,产物收率可达78%左右。本方法设计的合成路线步骤简单、反应时间短、易于操作和适合工业化。     

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。