采用二元模板剂合成MCM-22分子筛的研究

以硅溶胶和偏铝酸钠分别为硅源和铝源制备MCM-22,采用动态水热法合成MCM-22分子筛,考察了以六亚甲基亚胺和哌嗪二元模板剂对合成MCM-22分子筛的影响。XRD和SEM分析表明：采用二元模板剂能够合成较纯的MCM-22分子筛,并且表面形貌基本相同。     

咪唑改性MCM-22分子筛的制备及甲烷无氧芳构化性能

以硅溶胶为硅源,环己亚胺为模板剂,在动态条件下利用水热合成法合成了MCM-22分子筛,并在该体系下以咪唑为添加剂合成了咪唑改性MCM-22-I分子筛,考察了咪唑对MCM-22-I分子筛合成的影响,利用FTIR、XRD、SEM、ICP、BET、NH₃-TPD、H₂-TPR和TG/DTG等手段分别对咪唑改性前后分子筛的物化性质进行了表征。结果表明,咪唑改性能够增大MCM-22的比表面积、孔容和酸性,同时可有效降低模板剂HMI的用量。采用等体积浸渍法制备了6Mo/MCM-22和6Mo/MCM-22-I双功能催化剂,在连续流动固定床反应器上,反应温度700℃、反应压力1.01×10⁵Pa（1atm）、空速1500mL/(g-cat·h)的反应条件下,考察了催化剂催化甲烷无氧芳构化合成苯的催化剂性能。结果表明,与6Mo/MCM-22催化剂相比,咪唑改性的6Mo/MCM-22-I催化剂具有更高的择形性能和催化活性,甲烷的平均转化率提高了24.1%,苯的平均生成速率和选择性分别提高了24.3%和10.0%。     

MCM-22和MCM-49分子筛的合成

在Na2O-Al2O3-SiO2-HMI-H2O体系中。对MCM-22和MCM-49分子筛的静态晶化过程进行了研览。结果表明，晶化温度和硅铝比对MCM-22和MCM-49分子舜合成至关重要。晶化温度低（150℃）时，只能合成硅铝比鞋低的MCM-49分子筛；晶化温度高（180℃）时，可以合成较高硅铝比的MCM-49分子筛。同时发现碱庹高有和利于MCM-49分子筛的合成．而Na＋浓度以及模板剂的用量影响不大．     

MCM-22分子筛改性研究进展

综述了MCM-22分子筛改性的研究,分别评述了各种常用改性方法和原理,包括浸渍法、离子交换法、杂原子同晶置换法、酸碱处理、水热处理等方法。对MCM-22分子筛进行改性处理,调节MCM-22分子筛的孔结构及表面酸性,可以达到提高其反应选择性及催化性能的目的;并对以后MCM-22分子筛的改性进行了展望。     

新型MCM-22/MCM-41复合分子筛上FCC汽油降烯烃芳构化反应

采用纳米组装法合成MCM-22/MCM-41微孔/介孔复合分子筛,分别以H-MCM-22和H-MCM-22/MCM-41为催化剂,在固定床微反装置上对FCC汽油进行降烯烃芳构化的对比考察。结果表明,在反应时间2 h内,与MCM-22相比, MCM-22/MCM-41具有高的芳构化性能和持久的初始活性,复合分子筛汽油改质的产物中,芳烃体积分数由28.58%上升至51.1%,烯烃体积分数由34.04％降至5.8％。探讨了新型H-MCM-22/MCM-41复合分子筛用于FCC汽油改质的操作条件以及催化剂失活再生性能。结果表明,最佳反应条件为：反应温度400 ℃,压力2 MPa,空速3 h^-1。失活催化剂经过两次再生,降烯烃芳构化性能基本不变。     

制备条件对MCM-22分子筛催化异丁烯气相齐聚性能的影响

以六亚甲基亚胺为模板剂,硅溶胶为硅源,偏铝酸钠为铝源,采用动态水热法合成了MCM-22分子筛,并考察了MCM-22分子筛的Si与Al之比和制备条件对其催化异丁烯气相齐聚反应性能的影响.结果表明:Si与Al之比对其催化性能影响较小;MCM-22分子筛适宜的制备条件为晶化温度175 ℃、晶化时间72 h、焙烧温度500 ℃和离子交换浓度2 mol/L.异丁烯气相齐聚反应的实验结果表明, MCM-22分子筛具有较好的异丁烯齐聚活性,在反应温度225 ℃和体积空速240 h-1条件下, 异丁烯转化率大于50%,C8烯烃选择性大于95%.     

乙醇辅助剂对MCM-22分子筛结构及催化性能的影响

以六亚甲基亚胺为模板剂,乙醇为有机辅助剂,采用动态水热法合成了一系列MCM-22分子筛,利用X射线衍射(XRD)、氨程序升温脱附(NH3-TPD)、傅里叶变换红外光谱(FT-IR)和电子扫描显微镜(SEM)等表征手段考察了乙醇辅助剂对MCM-22分子筛的结构及酸性的影响.结果表明,添加适量的乙醇可以有效调控分子筛结构性能和结晶度,分子筛的强酸位的强度适度增强,弱酸位的强度减弱,总酸量和B酸中心数增大,而L酸中心数减少,且晶粒尺寸减小,比表面积增加,但过量的乙醇会导致ZSM-5分子筛的生成.以苯和丙烯烷基化合成异丙苯为模型反应,评价对所制备的分子筛催化性能,发现添加合适的乙醇得到的MCM-22分子筛具有更高的催化活性和选择性.     

改性MCM-22分子筛吸附脱除油品中二氯甲烷的研究

采用离子交换法制备了不同金属离子(Ni2+、Co2+、Fe3+)改性的MCM-22分子筛。采用XRD、NH3-TPD和BET对吸附剂进行了表征,同时,考察了MCM-22分子筛经不同金属离子改性后作为吸附剂对模型化合物的脱氯性能,优化了吸附剂的活化条件,并在吸附试验中研究了最优吸附剂吸附二氯甲烷的动力学和吸附活化能。结果表明,吸附剂的最优活化温度及时间分别为450℃和4 h。脱氯效果顺序为:Ni MCM-22Co MCM-22Fe MCM-22MCM-22,最优吸附剂Ni MCM-22分子筛上吸附动力学可用拟二级动力学进行较好的描述,吸附过程以化学吸附为主。     

HMCM-22/MCM-41的制备及其在甲苯碳酸二甲酯烷基化中的催化性能

以自制的HMCM-22作为原料,与中孔分子筛MCM-41的凝胶在水热条件下进行组装得到HMCM-22/MCM-41中微孔复合分子筛,采用XRD、N2吸附-脱附及NH3-TPD等方法对合成样品进行表征。结果表明,合成的样品同时具有中孔分子筛MCM-41与微孔分子筛HMCM-22的特点。采用固定床微型连续流反应器对HMCM-22/MCM-41复合分子筛催化甲苯与碳酸二甲酯(DMC)的烷基化反应性能进行了评价,考察了反应温度、甲苯与DMC摩尔配比及空速对烷基化反应的影响。实验发现,HMCM-22/MCM-41催化甲苯DMC烷基化反应的产物中,对二甲苯的选择性远高于间位和邻位异构体的选择性,表现出良好的催化活性和选择性。     

MCM-22、MCM-49和MCM-56分子筛的表征

MWW结构分子筛是一类新型的催化材料,具有独特的10元环孔道和12元环孔穴结构、优良的水热稳定性和特殊的酸中心分布,在多种反应中表现出良好的催化活性。以六亚甲基亚胺为模板剂,合成了具有MWW结构的MCM-22、MCM-49和MCM-56三种分子筛,并采用XRD、BET、TG/DTG和SEM手段对合成分子筛进行了表征,表明它们具有相同的单层结构,彼此之间的区别只有层间排列的结合层度和结合方式不同。MCM-56是薄层结构,晶体的层数少,MCM-22和MCM-49是多层结构,层数多。MCM-22的层间结合比较疏松,MCM-49的层间结合比较紧密。     

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。