分子筛负载铂催化剂上四氢萘加氢裂解反应行为

四氢萘是多环芳烃加氢转化的产物或者中间体,其加氢裂解行为和规律的研究在重芳烃转化和脱除领域有着重要的意义。采用等体积浸渍法制备得到了氧化铝负载贵金属(Pt,Ir和Pd)催化剂和酸性分子筛(MOR和ZSM-5)负载铂双功能催化剂,考察了它们催化四氢萘加氢裂解的反应行为。氧化铝为载体时金属催化剂表面主要发生加氢及脱氢反应,其中金属Pt表现出最高的加氢和脱氢活性。双功能催化剂上四氢萘发生加氢裂化、异构化、氢转移及烷基化等复杂反应,金属Pt通过氢溢流作用提高了分子筛Br?nsted酸活性从而提高催化剂加氢裂解活性和选择性,但过量金属Pt会加剧苯环加氢而不利于单环芳烃的生成。分子筛孔道的限域作用对四氢萘的反应活性及产物分布有重要影响,相比Pt/ZSM-5催化剂,Pt/MOR表现出更高的裂解活性及异构化选择性。Pt/MOR催化剂上四氢萘加氢裂解主要通过异构-裂解路径进行,异构化活性及异构体构型决定了裂解活性及产物的分布。     

改性丝光沸石催化剂上合成2,6-二异丙基萘

采用盐酸处理以及水热处理结合酸处理两种方法对氢型丝光沸石(HM)进行脱铝改性,制备了一系列脱铝HM催化剂,并以脱铝HM沸石为载体负载磷钨杂多酸(PW),制备负载杂多酸催化剂,用XRD、FT-IR和NH3-TPD等手段对这些催化剂的结构及酸性质进行了表征,在100mL间歇式不锈钢高压反应釜中对其在萘的异丙基化反应中的催化性能进行了考察。结果发现,随着脱铝深度的增加,HM沸石的酸量下降,酸强度降低,将PW负载于脱铝HM沸石载体上,其酸性质得到改善。上述催化剂的异丙基化反应结果表明,脱铝HM沸石的活性和2,6-DIPN选择性均大大高于未经改性的HM沸石;将PW负载于脱铝HM沸石上,其活性均有不同程度的上升,但对2,6-DIPN的选择性有所下降。催化剂的表征和反应结果显示,催化剂的活性和选择性与其孔结构和酸性质密切相关。     

氧化物改性丝光沸石催化剂上合成2,6-二异丙基萘

采用浸渍法负载B、P、Mg、La、Zr和Ce修饰水汽脱铝氢型丝光沸石,并采用固定床反应器对改性后丝光沸石催化萘烷基化反应的性能进行评价,结果表明,负载Ce是提高2,6-二异丙基萘选择性的有效方法。随着Ce浸渍量的增加,萘转化率降低,2,6-二异丙基萘的选择性提高,改性HM分子筛催化剂具有良好的再生性能。     

沸石分子筛孔道和表面化学修饰技术研究进展

沸石分子筛孔道和表面化学修饰是对分子筛进行二次合成的重要手段。本文综述了用离子交换法、化学沉积法和分子反应法等手段对各类沸石分子筛孔道和表面进行化学修饰改性的方法,研究结果表明,孔道和表面化学修饰可以精细调变沸石分子筛的孔道和孔口尺寸,钝化非选择性的表面酸性位,固载活性成分,提高分子筛的反应活性和对目标产物的催化选择性,为设计研制新型功能化的沸石分子筛提供有效的途径。     

硝酸改性丝光沸石上合成2,6-二异丙基萘

采用HNO3对丝光沸石(HM)进行脱铝改性,并采用固定床反应器对其萘异丙基化反应的性能进行评价,考察了不同脱铝方式和不同Si/Al原子比对改性HM萘异丙基化性能的影响。结果表明,水蒸汽和硝酸处理的催化剂,其B酸与L酸的比例和酸强度分布可发生变化,在保持较好的萘转化率的前提下,提高了2,6-二异丙基萘(2,6-DIPN)的选择性。随着HNO3改性后HM分子筛的Si/Al原子比的增加,催化剂活性逐渐降低,稳定性提高,选择性先提高后降低。适宜的硝酸改性脱铝工艺条件为:HM沸石先经500℃、0.5h-1的空速下高温水蒸汽处理1.0h,再用1.6mol/L的HNO3溶液于45℃下处理24.0h,此时Si/Al原子比为31,2,6-DIPN的产率为7.24%。     

混合分子筛对催化甲苯和三甲苯烷基转移性能的影响

以甲苯和三甲苯混合物为模型原料,研究了ZSM-5分子筛和12元环孔道丝光沸石及MAPO-36分子筛催化剂上的芳烃转化及烷基转移反应行为。在此基础上,对比了12元环孔道分子筛与ZSM-5混合分子筛催化剂的反应性能,尤其是MAPO-36分子筛在混合ZSM-5前后的性能变化。通过综合分析表征结果,并关联其在催化芳烃转化中的反应数据,发现ZSM-5与MAPO-36混合分子筛催化剂具有的孔道结构与酸性分布更利于烷基转移反应活性的最大限度发挥,反应温度可降20℃,氢耗降低,尾气量减少。     

分子筛上择形合成2,6-二烷基萘的研究进展

2,6-二烷基萘是非常有价值的有机化工原料.以萘或甲基萘为原料的择形烷基化合成2,6-二烷基萘的路线简单,被认为是最合理的技术路线.用酸性分子筛作为催化剂具有活性高、选择性好及环境友好等优点.从烷基化试剂、溶剂和分子筛催化剂的选择等方面,综述了分子筛催化下择形合成2,6-二烷基萘的研究进展.目前常用的分子筛催化剂有HY、Hβ、SAPO-5、HZSM-5和MCM-41等;所用的烷基化试剂主要是醇、烯烃、卤代烃和多烷基芳烃等;溶剂一般选用环己烷,也有少数选用四氢萘、二氧化碳和异辛烷等.     

萘的择形烷基化催化剂的改性研究

以丝光沸石为催化剂，用萘和异丙醇烷基化反应选择性合成2，6-二异丙基萘并对沸石脱钠、强酸脱铝、水蒸气处理、浸渍活性组分等处理，探讨了反应时间、反应温度、活性组分对沸石催化剂的影响。在250℃反应3h，铯(Ce)浸渍沸石催化剂的转化率和选择性都比较好，转化率达31．59％，β-/α-的选择性达6．8，2，6-/2，7-的选择性高达2．95。     

沸石封装金属纳米颗粒提高多相反应催化性能研究进展

金属和沸石分子筛是两种广泛应用于氧化还原和酸催化反应的重要催化剂,然而,金属纳米颗粒的团聚和烧结效应通常会导致反应过程中催化性能的损失。而具有均一孔道、结构多样性以及比表面积大等优点的沸石分子筛由于缺乏金属活性位极大地限制了其在催化反应中的活性和应用范围,因此,在沸石内部封装具有催化活性的金属纳米颗粒具有重要意义。综述重点介绍了近年来沸石封装金属纳米颗粒(金属@沸石)催化剂的研究进展,通过使用带有有机基团的稳定剂或晶种法等封装金属或金属氧化物的方法,有效地结合了金属颗粒的高活性以及分子筛载体的高选择性,提高反应活性的同时体现了金属-酸位点的协同催化性、选择性、抗浸出性和抗烧结性等优异性能,这些优势使得此类催化剂具有良好的工业应用前景。     

十氢萘在HY和Beta分子筛上加氢开环的研究

采用高温高压反应釜研究了十氢萘在低硅铝比HY分子筛[n(Si)/n(Al)=3.2]、Beta分子筛n(Si)/n(Al)=9.7]和双功能催化剂Pt-HY、Pt-Beta上的加氢开环反应,考察了分子筛孔道结构及酸性质、贵金属Pt及反应温度等因素对十氢萘转化率和产物选择性的影响。结果表明,十氢萘在Beta分子筛上的转化率较高,且有大量脱氢缩合产物（DHC）生成。Pt引入HY和Beta分子筛后,初始反应速率升高,十氢萘转化率增加,C₁₀产物中开环异构比增大,Beta分子筛上的脱氢缩合反应得到抑制。反应温度升高可以提高十氢萘在HY分子筛上的转化率,使得C₁₀产物选择性下降,而开环异构比（ROP/Iso）增大。     

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。