分子筛固载型Cosalen的制备、表征及其应用研究

分别采用NaY分子筛、γ-氨丙基三乙氧基硅烷修饰的MCM-41分子筛固载双水杨醛缩乙二胺合钴(Cosahn)配合物,制备了固载型Cosahn/NaY、Cosalen/MCM-41催化剂.采用傅里叶变换红外光谱、热重-差热、X射线衍射、比表面积测定等方法对固载型分子筛催化剂的结构进行表征.结果表明,Cosalen已成功地进入分子筛孔道内.在以氧气为氧源的环己烷氧化反应中,Cosalen/MCM-41催化剂具有较好的活性和对环己醇、环己酮的选择性.该催化反应体系产物中环己基过氧化氢(CHHP)的量很少,表明Cosalen/MCM-41催化剂能加速CHHP的分解.在初始氧气压力0.80 MPa、温度130℃、环己烷用量30 g、Cosalen/MCM-41用量0.30 g、叔丁基过氧化氢0.10 g的条件下反应2 h,环己烷的转化率达到5.96%,醇酮选择性87.03%.     

锆改性氧化铝负载的纳米金催化剂上环己烷氧化研究

通过浸溃法制备氧化锫改性的氧化铝载体,并采用改进的阴离子交换法(DAE)制备了负载型纳米金催化剂.以分子氧为氧化剂,考察了金催化剂在环己烷选择性氧化制环己酮和环己醇反应中的催化性能.结果表明,提高锆含量,环己烷转化率保持稳定,环己酮和环己醇总选择性,尤其是环己酮的选择性明显提高.随着金负载量增加,金颗粒增大,催化剂的活性降低,金颗粒在6nm以下的催化剂具有很高的催化活性.在423K,1.5MPa、3h反应条件下,0.6%(wt) 金和17%(wt)锆含量的催化剂上环己烷氧化得到9,5%的转化率,环己酮和环己醇的选择性分别为38.8%和51.5%.     

杂原子MCM-41分子筛对过氧化氢液相氧化环己烷的研究

分别考察了反应温度、过氧化氢用量及加入方式等因素对Cr、Fe和Ce改性后的杂原子MCM-41分子筛催化剂液相催化氧化环己烷制取环己酮反应的影响。研究结果表明，Cr-MCM-41〖JP〗催化剂具有较好的催化活性。选择适当的反应温度、过氧化氢用量和加入方式可以有效提高环己烷转化率和过氧化氢利用率。在70 ℃和n(C₆ H₁₂)∶n(H₂O₂)=1∶2条件下，采用两次加入过氧化氢的方式，环己烷转化率为33.7％，酮醇总选择性97.2％，n(环己酮)∶n(环己醇）＝1.99，过氧化氢利用率37.1%。     

催化氧化法合成环己酮技术研究进展

介绍了以环己烷为原料催化氧化合成环己酮的主要方法,分析了环己烷氧化采用的主要催化剂。环己烷硼酸催化氧化法和钴盐催化氧化法存在环己烷转化率低及结渣现象;分子筛催化氧化法、金属氧化物以及金属络合物仿生催化氧化法可提高环己烷转化率及醇酮选择性;金属络合物仿生催化氧化法具有良好的开发应用前景。     

纳米金复合催化剂制备及其低温选择催化环己烷氧化性能

采用光催化直接还原法将Au(0)负载在TiO2修饰的中孔分子筛MCM-41的孔道内外,采用XRD, N2吸附-脱附,FT-IR, TEM和EDS等手段对所制催化剂进行了表征,并考察了其在温和条件下对环己烷选择性氧化反应的催化性能. 结果表明,所制纳米金催化剂的分子筛载体仍具有较高的结晶度,金颗粒粒径在10 nm左右. 在环己烷氧化反应中,纳米金与TiO2光催化共同作用,使复合催化剂具有低温高催化活性. 在温度100℃、压力1.0 MPa及250 W紫外灯光照8 h的条件下,环己烷转化率高达3.9%,目的产物的总选择性为90.2%.     

环己烷分子氧选择性氧化固体催化剂研究进展

对环己烷分子氧催化氧化制环己酮固体催化剂的最新进展进行了综述,重点介绍了贵金属催化剂、过渡金属及其氧化物催化剂和分子筛催化剂。指出锆基复合氧化物催化剂和负载在分子筛上的金催化剂具有较高的催化活性和选择性及好的稳定性,具有一定的应用及工业化前景。     

双氧水氧化环己酮制ε-己内酯的Mg-Sn/TS-1催化剂协同效应研究

选择钛硅分子筛(TS-1)为载体，采用共沉淀法将镁-锡(Mg-Sn)双金属氧化物负载于TS-1上制得Mg-Sn/TS-1催化剂，对催化剂的晶相结构、微观形貌、比表面积和孔结构、组分结构进行了表征，并考察了其在双氧水氧化环己酮制备ε-己内酯中的催化性能。结果表明：制得的Mg-Sn/TS-1催化剂具有多孔结构，孔径分布较窄，Mg-Sn双金属氧化物均匀地负载在TS-1上；当Mg-Sn双金属氧化物摩尔比为3：1,Mg-Sn双金属氧化物与TS-1质量比为3：2,Mg-Sn/TS-1催化剂催化双氧水氧化环己酮制备ε-己内酯时的环己酮转化率为91.3%,ε-己内酯选择性为95.5%,催化性能较佳；Mg-Sn双金属氧化物之间具有良好的催化协同效应。     

MCM-48分子筛负载磷钨钼杂多酸催化合成环己酮1,2-丙二醇缩酮

以MCM-48分子筛负载磷钨钼杂多酸为多相催化剂,通过环己酮和1,2-丙二醇反应合成环己酮1,2-丙二醇缩酮.采用正交实验法探讨了MCM-48分子筛负载磷钨钼杂多酸对缩酮反应的催化活性,较系统地研究了原料用量、催化剂用量、带水剂用量、反应时间等因素对收率的影响.结果表明MCM-48分子筛负载磷钨钼杂多酸是合成环己酮1,2丙二醇缩酮的良好催化剂,在n(环己酮)n(1,2丙二醇)=11.6,催化剂用量为反应物料总质量的0.2%,环己烷为带水剂,反应时间1.0 h的条件下,环己酮1,2-丙二醇缩酮的收率可达90.7%.     

Pd/C催化硝基环己烷氢化制备环己酮肟

以Pd/C为催化剂,溶剂存在下硝基环己烷氢化制备环己酮肟.考察了溶剂种类、催化剂用量、反应时间、反应温度等因素对催化剂性能的影响.结果表明,溶剂的种类对硝基环己烷氢化产物的选择性有很大影响,乙二胺是该反应的合适溶剂.在催化剂与硝基环己烷摩尔比为1∶100、反应温度95 ℃的条件下,反应6 h后的硝基环己烷转化率可达100%,环己酮肟选择性可达84.2%.对硝基环己烷在碱性溶剂中氢化的反应机理作了初步探讨.     

Cr/SBA-15的优化合成及其环己烷氧化性能研究

采用高温水热嫁接的方法,通过调节反应溶液的p H和水热处理温度,成功地将金属铬离子嫁接到SBA-15氧化硅骨架上,制备得到高度规整有序的介孔孔道结构的Cr/SBA-15催化剂,并研究了Cr/SBA-15在以乙腈为溶剂,H_2O_2为氧化剂的环己烷催化氧化反应中的性能。结果表明,当p H=3,Si/Cr摩尔比为15时,合成的Cr/SBA-15催化剂具有高度有序的二维六方介孔结构,同时表现出良好的催化活性和选择性。反应温度为80℃,反应时间为4 h条件下,环己烷催化氧化的转化率可达17%,环己酮和环己醇的选择性分别为65%、35%。Cr/SBA-15催化剂重复使用3次后活性基本不变,表明该催化剂具有良好的稳定性。     

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。