叔戊烯与甲醇在Cs2.5H0.5PW12O40/SiO2 催化剂上的醚化

采用Cs2．5H0．5PW12O40／SiO2催化剂进行了叔戊烯与甲醇的醚化反应研究考察了催化剂制备方法和工艺条件对叔戊烯转化率的影响。研究结果表明，以硅胶为载体，在负载量40％、焙烧温度400℃条件下制备的Cs2．5H0．5PW12O40／SiO2催化剂具有较高的催化活性。在反应温度为80℃、压力为1．0MPa、n(甲醇)／n(叔戊烯)比为1．1、LHSV为1h-1的条件下，叔戊烯的转化率为68．57％。     

叔戊烯与甲醇在Cs2.5H0.5PW12O40/SiO2 催化剂上的醚化

采用Cs2.5H0.5PWi2O40/SiO2催化剂进行了叔戊烯与甲醇的醚化反应研究考察了催化剂制备方法和工艺条件对叔戊烯转化率的影响.研究结果表明,以硅胶为载体,在负载量40%、焙烧温度400℃条件下制备的Cs2 5H0.5PWi2O40/SiO2催化剂具有较高的催化活性.在反应温度为80℃、压力为1.0MPa、n(甲醇)/n(叔戊烯)比为1.1、LHSV为1h-1的条件下,叔戊烯的转化率为68.57%.     

Cs2.5H0.5PW12O40/SiO2催化剂上乙酸与烯烃酯化反应研究

以硅胶为载体,制备了负载型Cs2．5H0．5PW12O40催化剂。将制备的催化剂用于乙酸与1-丁烯的酯化反应。考察了活性组分负载量、焙烧温度、催化剂用量、反应温度、反应压力、n（1-丁烯）／n（乙酸）、反应时间等因素对乙酸转化率的影响。研究结果表明,在活性组分负载量为40％、焙烧温度为300℃时制备的Cs2．5H0．5PW12O40／SiO2催化剂具有较高的催化活性。随着负载量增大,催化剂孔径、孔容和比表面积减小,催化活性先增加后减小。在反应温度为120℃、压力为1．5MPa、n（1-丁烯）／n（乙酸）比为3．0、催化剂用量为4％、反应时间为7h的条件下,乙酸的转化率为87．36％。     

负载型Cs2.5H0.5PW12O40醚化催化剂的制备与催化性能

制备了负载型磷钨酸铯 (Cs2 5H0 5PW1 2 O4 0 )催化剂 ,考察了载体种类、载体性质、制备方法和制备条件对催化剂性能的影响 ,对制备的催化剂进行了表征 ,并考察了负载型Cs2 5H0 5PW1 2 O4 0 作为醚化催化剂的催化活性 结果表明 ,大孔硅胶是Cs2 5H0 5PW1 2 O4 0 的适宜载体 ,硅胶的钠含量越低制备的Cs2 5H0 5PW1 2 O4 0 SiO2 催化剂的活性越高 .采用一步法和二步法制备的Cs2 5H0 5PW1 2 O4 0 SiO2 催化剂均具有较强的酸性、催化活性以及良好的稳定性 ,可以替代液体酸和阳离子交换树脂 ,成为一种环境友好的固体酸催化剂     

硅胶负载磷钨酸铯盐(Cs2.5H0.5PW12O40)催化合成2-乙酰噻吩的研究

采用二步浸渍法制备硅胶负载磷钨酸铯(Cs2.5H0.5PW12O40)催化剂催化合成药物中间体2-乙酰噻吩.运用IR和XRD测试技术进了Cs2.5H0.5PW12O40/SiO2催化剂的表征,考察了Cs2.5H0.5PW12O40负载量、催化剂用量、物料配比、反应温度、反应时间等对2-乙酰噻吩合成收率和选择性的影响.实验结果表明,Cs2.5H0.5PW12O40和Cs2.5H0.5PW12O40/SiO2催化剂保持H3PW12O40的Keggin结构不变,且Cs2.5H0.5PW12O40/SiO2催化剂中Cs2.5H0.5PW12O40主要聚集在SiO2载体表面.优化合成2-乙酰噻吩的工艺条件为:30%Cs2.5H0.5PW12O40/SiO2催化剂用量为3%(以总物料量计);噻吩与乙酐的摩尔比为4:1;反应温度为75～80℃;反应时间为90 min.在此所选择的条件下,2-乙酰噻吩的收率达94.6%～96.8%,选择性达99.8%～99.9%.     

负载型磷钨杂多酸的制备及在醚化反应中的应用

以活性炭为载体,制备了催化剂H3PW12O40（PW12）／C,并进行了混合烯烃与甲醇的醚化反应。研究了制备条件、PW12负载量对催化活性的影响,并对醚化反应条件进行了系统考察。     

纳米H3PW12O40／SiO2复合杂多酸催化合成乙酸正己酯

以纳米二氧化硅为载体,采用溶胶-凝胶法负载磷钨酸,以冰乙酸、正己醇为原料,纳米H3PW12O40／SiO2复合杂多酸为催化剂,考察原料配比、催化剂用量、反应时间、反应温度等因素对酯化反应的影响,同时也考察了催化剂循环使用的情况。实验表明,纳米H3PW12O40／SiO2复合杂多酸催化剂是合成乙酸正己酯的良好催化剂,其最优合成条件为：纳米H3PW12O40／SiO2复合杂多酸催化剂用量约为反应酸醇配料总质量的2．5％,酸醇配比为1：1．4,反应时间1h,反应温度130℃,产率达89．72％。     

H3PW12O40／SiO2催化合成苹果酯-B

以H3PW12O40／SiO2为催化剂,对以乙酰乙酸乙酯和1,2-丙二醇为原料合成苹果酯-B的反应条件进行了研究。考察了原料物质的量比、催化剂用量（质量）、带水剂用量（质量）、反应时间对产品收率的影响。试验结果表明H3PW12O40／SiO2是合成苹果酯-B的良好催化剂,最佳反应条件为：n（乙酰乙酸乙酯）：n（1,2-丙二醇）=1：1．5,催化剂质量为反应物总质量的0．8％,带水剂环己烷6mL,反应时间90min。上述条件下,苹果酯-B的收率可达68．9％。     

H3PW12O40-TiO2/SiO2超声光催化降解罗丹明B的研究

以硅胶为载体,采用浸渍法制备了H3PW12O40-TiO2/SiO2催化剂.通过对染料罗丹明B的超声光催化降解,探讨了催化剂的组成、用量、酸度、催化剂重复使用次数等因素对罗丹明B降解率的影响.结果表明:含4gH,PW12O40的TiO2溶胶浸渍在11gSiO2上的催化效果最佳.催化剂最佳用量为0.2g.初始罗丹明B溶液的pH为1时,反应速率最快.催化剂经活化处理后,重复使用6次,对罗丹明B的降解率仍达95.65%.相同条件下比较H3PW12O40-TiO2/SiO2和TiO2/SiO2对罗丹明B的降解效果发现,H2PW12O40可显著提高TiO2超声光催化降解罗丹明B的降解率.     

Cs2.5H0.5PW12O40/SiO2催化合成二甘醇二苯甲酸酯

以硅胶为载体，制备了固载磷钨酸酸式铯盐(Cs2．5H0．5PWl2O40／SiO2)催化剂，并用于催化合成二甘醇二苯甲酸蘸(DEDB)。研究了催化剂制备条件对催化性能的影响和反应条件对蘸化反应的影响。在n(酸)/n(醇)=2．2、催化剂用量为0．7％、反应温度80℃、反应时间4h、带水剂N2流量250mL的条件下，酯化率可达到99．67％。催化剂重复试验表明，该催化剂具有良好的活性与稳定性。     

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。