浆料催化精馏制备甲缩醛

研究了以甲醇和甲醛为原料,以大孔径强酸性阳离子交换树脂为催化剂,通过浆料催化精馏工艺制备甲缩醛的可行性。考察了催化剂含量、进料醇醛比、进料总流量和回流比等因素对该过程的影响。在选定的试验条件下,甲缩醛收率可达89%以上,塔顶甲缩醛的质量分数可达0.99以上。结果表明,该工艺用于制备甲缩醛是可行的。     

催化反应精馏制甲缩醛

在催化反应精馏制甲缩醛的工艺中,影响因素很多,如催化剂含量、进料醇醛比、甲醛浓度、回流比和塔顶采出。实验以甲醇和甲醛为原料,以硫酸为催化剂催化精馏制甲缩醛,在其他条件不变得情况下,通过改变采出率,考察了塔顶采出塔顶采出对甲缩醛收率和纯度的影响。     

甲缩醛氧化反应过程分析

甲缩醛在钼铁催化剂上的空气氧化反应是一个复杂的并行、连串反应。通过实验考察了其中几个主要的单一反应。为寻找高收率甲缩醛的最佳工艺条件提供了依据，并为研究反应动力学打下了基础。文中提出在原料中添加适量水可以显著提高甲醛收率。     

连续萃取催化精馏制备高纯度甲缩醛

研究了以甲醇和甲醛为原料,大孔径阳离子交换树脂为催化剂,通过将萃取精馏和催化精馏相耦合的方法制备高纯度甲缩醛,证明了这种工艺的可行性。在内径为35 mm、高为2700 mm的玻璃反应精馏塔内进行实验,考察了总进料量、萃取剂进料位置、醇醛摩尔比、回流比以及用甲醛溶液作为萃取剂对甲醛转化率和甲缩醛纯度的影响。在选定的实验条件下,甲醛的转化率可达到97.82%以上,甲缩醛纯度可达到97.64%（含甲醛0.79%、水1.41%、甲醇0.20%）。     

反应精馏生产甲缩醛工艺的研究

对合成甲缩醛反应精馏过程进行了模拟和实验,分析了过程操作参数回流比、进料位置、醇醛进料摩尔比的变化结果的影响,模拟结果表明,当精馏段级数为11,反应段级数为26,提馏段为5,回流比为3,甲醇和甲醛的进料位置分别为第37级和第12级,甲醇/甲醛(摩尔比)=2.1时,塔顶可得到质量分数大于99.5%的高纯度甲缩醛。并通过反应精馏实验对模拟结果进行验证,实验结果与模拟结果吻合较好。     

甲醛低聚反应研究

以甲缩醛为原料合成聚缩醛二甲醚,考察了催化剂、反应温度、物料配比、反应时『司、搅拌转速等因素对反应的影响。结果表明：以树脂为催化剂,催化剂用量5、vt％左右,甲醛和甲缩醛的摩尔比为1．0～1．5：1,反应温度96～105℃,搅拌转速为600～800r／min,通入的N2初始压力0．8～1．0MPa。在此条件下反应4～6h,反应转化率达到65％左右,选择性为90％左右。     

反应精馏制备甲缩醛的过程模拟与优化

使用Aspen Plus11.1模拟甲醇与甲醛反应精馏制备甲缩醛的过程,模拟过程采用了NRTL模型,对进料温度、进料位置、回流比进行了灵敏度分析,得到了较佳工艺参数为:进料温度40℃,进料醇醛摩尔比2∶3,进料位置为第9块塔板,回流比8。模拟得到了反应精馏塔的温度和浓度分布,对于甲缩醛的工业化生产有着重要的作用。     

酸性离子液体催化精馏制备甲缩醛的研究

通过咪唑、氢氧化钠和溴代烷烃反应生成了烷基咪唑,再与丁基磺酸内酯反应,经硫酸化直接制备了烷基咪唑酸性离子液体,以离子液体作为催化剂催化精馏制备甲缩醛,考察不同因素对催化精馏的影响,结果表明,当进料中醇醛摩尔比为3∶1,总进料量为20.1 m L/min,催化剂用量为3%(甲醛溶液质量),釜底加热温度为250℃,回流比为1时,催化精馏效果最优,此时甲醛转化率为66.70%,塔顶产品纯度为96.48%(质量百分数)。     

甲缩醛氧化制高浓度甲醛催化剂的开发与研究

所研制的。Mo-Fe-Cr-O甲缩醛氧化制高浓度甲醛催化剂的最适宜工艺条件为反应温度360~380℃ , 混合气空速7000-1000h^-1, 甲缩醛:O₂=1:2(摩尔比).它具有良好的热稳定性和重现性, 催化剂制备技术可靠, 小试寿命超过1000h。单管反应器考察结果表明催化剂具有很高的活性和选择性, 甲缩醛转化率为100%。 甲醛选择性为93.5%~95.4%, 具有工业应用价值。     

固体超强酸SO42-/Fe2O3的制备及其对甲缩醛合成反应的催化性能

以Fe(NO3)3、NH3·H2O和H2SO4为原料,采用直接沉淀法制备了固体超强酸SO42-/Fe2O3催化剂,用于甲醇与甲醛催化合成甲缩醛的反应.围绕焙烧温度对催化剂催化活性的影响进行了考察,得到了最佳焙烧温度.用X-射线衍射(XRD)、红外光谱(IR)、比表面积(BET)、pH测试等方法对催化剂进行了表征,得到了催化剂比表面积、晶型、活性中心结构等性能参数,使用优化条件下制备的催化剂,反应可得59 wt％甲缩醛的馏出液.     

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。