多孔壳聚糖微球/钯催化剂应用于水相Heck反应

以与壳聚糖具有一定相容性的水溶性高分子(聚乙二醇)为致孔剂,通过相转变法制得了多孔壳聚糖微球负载钯催化剂.利用扫描电镜、ICP-AES等对催化剂进行了表征.结果表明,所制备的壳聚糖基多孔微球具有高度开放的多孔结构,钯可有效的进入高分子微球的孔道中实现有效负载.该负载型催化剂能较好地催化丙烯酸丁酯与芳基碘系物的水相Hec...     

季铵型壳聚糖插层蒙脱土的制备及对Cr(Ⅵ)吸附作用的研究

制备季铵型壳聚糖插层蒙脱土,采用红外光谱、X-射线图谱和扫描电镜分析研究表明,壳聚糖季铵盐—2-羟丙基三甲基氯化铵壳聚糖进入到了蒙脱土的层间,使层间距增大,形成了插层复合物。利用所得产品对含Cr(Ⅵ)水样进行处理,在pH为4、吸附t为100 min、吸附剂质量浓度为2 g/L和Cr(Ⅵ)初始质量浓度为50 mg/L的优化条件下,季铵型壳聚糖插层蒙脱土复合吸附剂对Cr(Ⅵ)的吸附量为5.61 mg/g,去除率为89.73%。季铵型壳聚糖插层蒙脱土复合吸附剂对Cr(Ⅵ)的吸附符合Langmuir吸附模型。     

插层聚合法制备MMT/聚乙烯纳米塑料

本研究以2,6-二乙酰基吡啶、2,4,6-三甲基苯胺和FeCl2.4H2O为原料,制备了后过渡金属铁的二亚胺配合物。将其负载在改性蒙脱土上,以己烷为溶剂、AlEt3为助催化剂进行聚合反应。通过红外光谱、X射线分析、热分析等,系统地研究了蒙脱土的改性条件对蒙脱土结构、蒙脱土载体铁系催化剂的聚合行为及聚合物结构与热性能的影响。研究表明最佳插层条件是：1831为插层剂、80℃、反应2 h、蒙脱土/1831（质量比）为3/1,此时层间距为2.72 nm,催化剂活性达1.073×106（g PE/mol Fe.h）,聚乙烯堆密度为0.351g/cm3,形成MMT/PE纳米塑料。     

蒙脱土负载［C14mim］+有机阳离子催化合成柠檬酸三丁酯

通过咪唑基离子液体和蒙脱土在甲苯溶液中的离子交换反应，将热稳定性高的咪唑基有机阳离子［C₁₄mim］⁺交换吸附进入蒙脱土片层间，制备了蒙脱土负载的有机阳离子固体催化剂［C₁₄mim］⁺/MMT。利用XRD和TGA对催化剂的结构与性能进行了表征和测定，研究了蒙脱土负载有机阳离子固体催化剂的催化性能，初步考察了其稳定性及再次使用效率。研究结果表明，［C₁₄mim］⁺/MMT在合成无毒增塑剂柠檬酸三丁酯的酯化反应中表现出较高的催化活性，可循环使用。与未负载的C₁₄mimBF₄相比，［C₁₄mim］⁺/MMT具有催化活性高、稳定性好和易分离的特点。     

蒙脱土负载型固体酸催化剂的烷基化性能与结构研究

以酸化后蒙脱土为载体，采用浸渍蒸发法制备了环境友好的蒙脱土负载znCl2型固体酸催化剂。研究了蒙脱土酸化处理、ZnCl2负载量及活化温度对催化剂烷基化活性的影响，并初步考察了催化剂的稳定性，比较了几种不同酸催化剂的烷基化活性。利用XRD、BET、TG—DTA、吡啶吸附FTIR对催化剂的结构进行了表征和测定；结果表明，蒙脱土酸化处理后形成的孔道有利于负载ZnCl2，ZnCl2与蒙脱土的羟基之间存在着化学键合，经活化后转化成Zn(0H)C1。蒙脱土负载ZnCl2后明显地提高蒙脱土表面的总酸量，催化剂活性与其表面总酸量之间有关，催化剂表面L酸与B酸的共存有利于其烷基化活性的提高。实验条件下，蒙脱土负载ZnCl2型催化剂在苯与氯节的烷基化反应中表现出较高的催化活性，二苯甲烷的收率最高可达83．6％。与其它Lewis酸试剂及酸化蒙脱土相比，蒙脱土负载型催化剂催化活性大有提高。     

聚乙烯/蒙脱土纳米复合材料的制备及性能研究

以蒙脱土／十六烷基三甲基溴化铵作为前驱物负载Ziegler-Natta催化剂，通过插层原位聚合的方法制备了聚乙烯／蒙脱土纳米复合材料。对聚乙烯／蒙脱土纳米复合材料的制备规律进行了研究。用透射电镜、扫描电镜、XRD，DSC等手段研究了结构和性能的相互关系，以及蒙脱土的含量对复合材料熔点与结晶行为的影响。研究表明：蒙脱土的片层结构被破坏，并以纳米级均匀分散在聚合物基体中。蒙脱土的质量分数为3％左右时，聚乙烯／蒙脱土纳米复合材料具有优良的综合性能。     

硅钛柱撑蒙脱土微孔材料的制备与表征

合成了一种硅钛柱撑蒙脱土微孔材料.用十六烷基三甲基溴化铵改性蒙脱土,制得有机蒙脱土,再以正硅酸乙酯为硅源,采用溶胶-凝胶法,在正硅酸乙酯-蒙脱土水溶液中加入四氯化钛,以四氯化钛作为硅柱前驱体进入粘土片层间反应的驱动力,在钛阳离子的驱动下,使正硅酸乙酯在蒙脱土的片层之间发生水解缩合反应,制备了硅钛柱撑蒙脱土微孔复合材料.用XRD、DTA以及N2吸附脱附测试,分别对材料进行了表征.XRD测试结果表明:复合材料的最大层间可达到17.7 A.;DTA测试结果表明:改性后蒙脱土复合材料的热稳定性明显提高了;N2吸附脱附曲线以及孔径分布曲线说明合成的多孔材料中多为微孔分布,平均单孔体积为0.14 cc/g,平均孔径达到17.5 A.,SBET表面积由30.2 m2/g增加到242.0 m2/g.这种材料以其柱撑多孔结构,作为环保材料如:吸收剂、催化剂应用,具有广阔的发展前景.     

界面溶蚀法制备多孔磺化聚苯乙烯/壳聚糖微球及其Cr~(3+)吸附研究

采用固/液界面溶剂溶胀诱导相分离法,对磺化聚苯乙烯(SPS)和表面负载有生物相容性的壳聚糖(CS)的核壳型SPS/CS两种微球进行溶蚀,制备出具有多孔结构的SPS和SPS/CS微球。研究发现,溶剂类型和醇水比是影响多孔聚合物微球形态的主要因素。利用透射电镜(TEM)对多孔微球的结构进行表征,通过紫外可见分光光度计(UV-Vis)测定SPS/CS多孔微球在室温环境下对Cr3+的吸附行为。结果表明,界面溶蚀法可制备出形貌均一的多孔聚合物微球,其对Cr3+吸附量明显优于实心结构的微球。     

负载羧基有机蒙脱土制备环氧树脂纳米复合材料(英文)

用椰油酰胺丙基甜菜碱(CAB)制备了1种负载羧基的有机蒙脱土,并将这种有机蒙脱土加入甲基四氢苯酐固化环氧树脂体系中制得环氧树脂/蒙脱土纳米复合材料。采用XRD衍射和透射电镜TEM研究了蒙脱土有机化前后和在纳米复合材料中的片层结构和形态。用TGA研究了纳米复合材料的热稳定性能。结果表明,制备的负载羧基蒙脱土充分插层且很容易分散在环氧树脂中得到纳米复合材料。其热稳定性和有机蒙脱土在树脂中的分散状态有关。     

壳聚糖微球的应用研究

壳聚糖是甲壳素脱乙酰化后的产物,由于它具有生物相溶性、可生物降解、无毒、吸附等特性,已广泛应用于医学、食品等方面。壳聚糖微球除具有壳聚糖本身特点外,在性能上又有新的改善。本文从壳聚糖微球作为药物缓释、基因治疗、螯合金属离子、负载催化剂、吸附染料等用途出发,对其应用前景进行了简单的综述。     

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。