环氧化物、CO_2和甲醇一步合成碳酸二甲酯

用无毒,廉价,操作简单的负载型氧化物为催化剂。浸渍法制备了Na_2SiO_3/MgO催化剂,用XRD、CO_2-TPD等手段对其进行了表征,并在高温高压反应釜中进行了以CO_2、环氧丙烷(PO)和甲醇为原料一步法合成碳酸二甲酯。结果表明:Na_2SiO_3/MgO催化剂具有良好的催化性能,催化剂活性组分均匀地分散在载体上且与载体有明显的强相互作用,在最佳反应条件(V_(CH_3OH)∶V_(PO)=3∶2、反应时间5h、反应压力为2.0MPa、反应温度为160℃)下,环氧丙烷转化率为100%,DMC收率达到42.16%。     

高分子金属配合物用于合成碳酸二甲酯的催化性能

研究了以二氧化硅负载聚丙烯腈-丙烯酰胺-金属(PAN-AM-M)配合物为催化剂，在环氧氯丙烷存在下，由甲醇和二氧化碳直接合成碳酸二甲酯的反应活性。考察了反应条件的影响。结果表明，PAN-AM-Zn表现出较高活性，合成碳酸二甲酯的最佳反应条件为：甲醇与环氧氯丙烷的原料配比为4：1，反应温度130℃，催化剂用量2％(反应物料质量百分数)。     

酯交换法合成碳酸二甲酯的催化剂研究

章文以活性炭、γ-Al2O3、ZrO2、SiO2、4A和5A为载体,负载碱金属氢氧化物、碱金属碳酸簸、碱金属硝酸盐等制锯了不同的固体碱催化剂用于碳酸丙烯酯和甲醇酯交换合成碳酸二甲酯的反应,并在高压釜中考察了催化剂的反应性能。结果表明：以氢氧化钠为活性组分,5A分子筛为载体,负载量15％,焙烧温度为600℃,反应温度120℃,反应初始压力为0．2MPa的反应条件下碳酸丙烯酯的转化率为50．8％,碳酸二甲酯的收率和选择性分别为50.3％和99.0％。     

硅胶包覆型催化剂在气相法合成碳酸二甲酯中的性能

针对甲醇气相氧化羰基化直接合成碳酸二甲酯反应,采用溶胶凝胶法制备了硅胶包覆的新型多相催化剂PdCl_2-CuCl_2-KOAc-AC@SiO_2。考察了硅胶/活性炭/金属活性组分量的比对催化剂性能的影响。结果表明,硅溶胶/活性炭/金属活性组分的量比(mL/g/g)为22.0:4.5:1.0时,碳酸二甲酯的空时收率(STY)较负载型PdCl_2-CuCl_2-KOAc/AC催化剂提高了21%。并且包覆型催化剂在空气中的存放稳定性明显优于负载型催化剂,易于保存。催化剂活性的提高是SiO_2和AC载体协同作用的结果,SiO_2提高了催化剂的存放稳定性。     

酯交换合成碳酸二苯酯催化剂的研究进展

对近年来碳酸二甲酯和苯酚酯交换合成碳酸二苯酯的催化剂体系进行了较为系统的概述,包括均相催化剂体系(碱或碱金属化合物、Lewis酸、锡和钛的有机化合物等)和多相催化剂体系(各种负载型、金属氧化物、水滑石等),认为开发有机锡、有机钛配合物催化剂以及将其固载化是碳酸二甲酯与苯酚酯交换反应合成碳酸二苯酯催化剂研究的重要方向.     

酯交换法合成聚碳酸酯二醇的研究进展

综述了酯交换法合成聚碳酸酯二醇(PCDL)的研究进展.通过对碳酸二甲酯、碳酸二乙酯、碳酸乙烯酯、碳酸二苯酯等用于酯交换合成PCDL进行了比较,指出碳酸二苯酯与二元醇合成PCDL是最具工业化前景的方法.对碱金属化合物、有机金属化合物、有机胺类化合物、Mg/Al水滑石、负载型催化剂、酶等催化剂的催化性能作了评述.     

KF/γ-Al2O3催化甘油酯交换合成碳酸甘油酯

采用等体积浸渍法制备了一系列氧化铝负载碱金属氟化物固体碱催化剂,用于甘油(丙三醇)与碳酸二甲酯酯交换反应合成碳酸甘油酯,其中KF/γ-Al2O3催化剂能够更好地促进碳酸甘油酯的生成。进一步考察了KF/γ-Al2O3催化剂的制备条件、反应条件对甘油与碳酸二甲酯酯交换反应的影响。当KF负载在γ-Al2O3的负载量为15%(质量分数,下同),于400℃焙烧5 h后制得固体碱催化剂,在n(碳酸二甲酯)∶n(甘油)=3∶1,反应温度80℃,反应时间1.5 h的条件下,甘油的转化率达96.1%,碳酸甘油酯选择性和收率分别达98.1%和94.3%。     

负载型路易斯酸-超强碱双功能催化剂作用下的碳酸二甲酯直接合成

利用浸渍-焙烧法制备了负载型路易斯酸-超强碱双功能催化剂,并使用其一步直接由二氧化碳、甲醇和环氧丙烷合成碳酸二甲酯,并研究了催化剂负载量、反应的温度和时间、原料配比对反应结果的影响.指出了催化反应的机理,实验结果还显示焙烧对催化剂的超强碱活性位的形成有关键作用.     

二氧化碳和甲醇直接合成碳酸二甲酯研究进展

从均相及多相催化剂体系和反应条件等方面,综述了近年来二氧化碳和甲醇直接合成碳酸二甲酯的研究开发最新进展。介绍了均相催化剂体系包括有机金属烷氧基化合物、碱土金属烷氧基化合物、碱性催化剂和乙酸盐催化剂;多相催化剂体系包括负载型金属催化剂、负载型固体碱催化剂和氧化物催化剂。对催化剂及反应体系的设计、光催化剂、杂多酸催化剂、离子液体体系、助催化剂及吸水剂的使用、微波加热、膜反应器以及超临界二氧化碳溶剂体系进行了评述。     

1-烯丙氧基-2,3-环氧丙烷的制备

以烯丙醇和环氧氯丙烷为原料,在混合催化剂存在下开环得中间体,中间体再在碱液作用下闭环生成1-烯丙氧基-2,3-环氧丙烷。在n(烯丙醇)∶n(环氧氯丙烷)=3∶1、混合催化剂0.8 g/mol环氧氯丙烷、开环反应温度≥95℃条件下,收率为81.4%,纯度99%以上。工艺简单易行,催化剂选择性高,回收的原料可循环使用,产品生产成本低。     

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。