Keggin型杂多酸盐催化氧化甲苯制备苯甲醛

在以叔丁基过氧化氢(TBHP)为氧化剂,乙腈为溶剂的条件下,利用Keggin型Co3H2PV2Mo10O40杂多酸盐为催化剂催化氧化甲苯制备了苯甲醛。用红外光谱分析(IR)、X射线衍射(XRD)方法对催化剂进行了表征。实验表明,在90℃反应6 h,甲苯转化率为28.5%,苯甲醛的选择性达55.5%。     

V-MCM-41介孔分子筛的合成与催化性能

采用三乙醇胺络合物法制备了骨架中含钒量较高的V—MCM-41分子筛催化剂,利用X射线衍射（XRD）和紫外漫反射光谱（UV—vis DRS）等技术对催化剂进行了表征,并考察了硅钒比、反应温度、体积空速、空气与甲苯比对V-MCM-41分子筛在甲苯气相选择性氧化制苯甲醛反应中催化性能的影响。结果表明,骨架中的钒是甲苯选择性氧化生成苯甲醛的活性中心,钒进入骨架中的量与硅钒物质的量比有关,当硅钒比为30时,进入骨架的钒最多,且在甲苯选择性氧化反应中对苯甲醛选择性最高。以硅钒比为30的V-MCM-41分子筛为催化剂,常压下甲苯氧化制苯甲醛较合适的反应工艺为体积空速800h^-1,空气与甲苯物质的量之比5,反应温度450℃。在此条件下,甲苯转化率为20．8％,苯甲醛选择性为41．8％,苯甲醛收率为8．7％。     

甲苯氧化制备苯甲醛工艺研究

研究了在常压下以Co/Mn/Br为催化剂、醋酸为溶剂的甲苯液相选择性氧化制备苯甲醛的反应过程。比较了不同类型催化剂对反应的影响,考察了反应温度与钴含量的影响,确定温和氧化条件下Co/Mn/Br的优化配比关系,获得了优化反应条件:催化剂为Co(OCOCH3)2/MnSO4—Mn(OCOCH3)2/C2H2Br4,反应温度98℃,n(Co)∶n(甲苯)=3.0∶100,n(Br)∶n(Co)=0.24%,n(Co)∶n(Mn)=3∶1。在该条件下甲苯转化率为48.69%,苯甲醛产率可达21.02%。     

MnK/Al2O3催化苯甲醇液相氧化制苯甲醛

采用共浸渍法制备Mn1K1/Al2O3催化剂,并以分子氧为氧化剂考察了其在苯甲醇液相氧化制苯甲醛反应中的催化性能。实验结果显示,焙烧温度和负载量对催化剂性能有重要影响,773 K焙烧的10%(wt)Mn1K1/Al2O3具有最高的催化活性,373 K下反应3 h时,苯甲醇转化率为72.9%,苯甲醛选择性为99%,且该催化剂可循环使用6次以上而其催化活性无明显降低。粉末X射线衍射(XRD)、N2物理吸附、拉曼光谱、X射线吸收光谱(XAS)、程序升温还原(H2-TPR)结果表明,负载在Al2O3表面的非晶态或小晶粒α-Mn O2是催化活化分子氧发生醇氧化反应的高活性物种。     

甲苯液相选择性氧化制苯甲醛的工艺研究

甲苯与空气液相选择性氧化是一条制备苯甲醛的绿色化生产路线。建立了一套甲苯液相空气氧化的连续化试验装置,在工业装置操作条件下,通过加入含氮杂环化合物助催化剂,提高了甲苯转化率和苯甲醛选择性。研究结果表明,加入苯并咪唑助催化剂100 mg·kg~(-1)后,甲苯转化率为17.3%,苯甲醛选择性为6.6%。     

Au-Ru/TiO2催化硝基苯和苯甲醛一锅法合成N-苄基苯胺

采用沉积-沉淀法制备出一系列Au-Ru/TiO2双金属催化剂,用于硝基苯与苯甲醛一锅法加氢反应合成N-苄基苯胺。考察了Ru负载量对Au-Ru/TiO2加氢性能的影响,并采用X射线衍射和扫描电镜等方法对催化剂进行表征。结果表明,Au和Ru产生协同作用共同促进加氢作用。负载Ru质量分数为1.5%的催化剂具有最好的加氢活性和N-苄基苯胺选择性。优化的N-苄基苯胺合成工艺条件为：催化剂用量占硝基苯质量的15%,溶剂为甲苯,氢压1.1 MPa,反应温度80 ℃。此条件下,硝基苯转化率100%,N-苄基苯胺选择性88.2%     

Fe2O3/AC催化剂上对甲基苯硫酚的水相催化氧化偶联

以对甲基苯硫酚为模型底物，空气为氧化剂，来研究硫醇水相催化氧化偶联制备二硫醚。以活性炭为载体，采用等体积浸渍法制备了一系列负载型氧化物催化剂，并考察了其在对甲基苯硫酚氧化偶联制备对甲苯二硫醚反应中的催化性能。反应结果表明，活性炭负载的铁氧化物具有最佳催化性能。采用N₂物理吸附、X射线衍射、X射线光电子能谱和透射电镜等表征手段对活性炭负载的铁氧化物催化剂进行了表征。表征结果表明，铁氧化物为高度分散在活性炭上的Fe₂O₃物种。以Fe₂O₃/AC为催化剂，当催化剂焙烧温度为400℃，Fe负载量为5%，在50℃下反应30min时，对甲苯二硫醚的收率高达97.4%；该催化剂循环使用5次后活性无明显下降。     

甲苯催化氧化制备苯甲醛的合成研究

采用水热晶化法制备了SBR-15分子筛,探讨了不同金属作为催化剂和助剂时的催化剂活性。结果表明,1.5%Mn_2O_3-5%Fe_2O_3-SBR-15分子筛催化剂的催化活性最优,在常压、反应温度90℃的条件下,甲苯的转化率为13.98%,苯甲醛的选择性为48.32%。BET的表征结果表明,添加少量的Mn_2O_3(1.0%),能较小程度地增加Fe_2O_3-SBR-15分子筛催化剂的比表面积。催化剂的热稳定性结果表明,72h内,催化剂对苯甲醛的选择性一直保持在40%以上,甲苯的转化率随反应时间的增加逐渐下降直至失活。     

无溶剂下钴卟啉/NHPI催化甲苯选择性氧化制备苯甲醛

以钴卟啉/N-羟基邻苯二甲酰亚胺(NHPI)为催化剂，分子氧为氧化剂，在无溶剂的条件下，研究温和条件下催化甲苯选择性氧化制备苯甲醛的工艺。在甲苯0.2 mol、钴卟啉物质的量分数1×10^-4%、NHPI物质的量分数0.25%、70℃、O₂压力2.0 MPa和3 h优化条件下，甲苯转化率为5.5%,苯甲醛、苯甲醇和苯甲酸选择性分别为88.0%、10.2%和0.8%。通过原位红外和电子顺磁共振波谱仪等表征方法，表明该反应机理为典型的自由基反应过程。     

三聚磷酸二氢铝/载硫硅藻土催化合成苯甲醛乙二醇缩醛

以苯甲醛、乙二醇为原料,三聚磷酸二氢铝/载硫硅藻土为催化剂合成苯甲醛乙二醇缩醛。采用单因素实验,考察了醇醛摩尔比、催化剂用量及反应时间对产品收率的影响;利用中心组合设计实验和响应面实验获得较佳工艺条件。结果表明,在三聚磷酸二氢铝/载硫硅藻土催化合成苯甲醛乙二醇缩醛中,各因素影响的顺序为:醇醛摩尔比反应时间催化剂用量。多元回归模型方差分析结果显示优化反应条件为:反应温度115℃,反应时间1.23 h,醇醛摩尔比2.6,苯甲醛21 g,催化剂用量为反应物总质量的1%,带水剂甲苯30 m L,苯甲醛乙二醇缩醛的收率为88.1%。该催化剂经5次重复使用后,收率仍可达86.1%。     

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。