对二甲苯液相催化氧化动力学(Ⅰ)反应机理和动力学模型

针对PX高温液相催化氧化过程的特点开发了一套气液固三相反应实验技术 ,进行了氧化过程的动力学实验研究 .根据自由基反应机理和Co Mn Br三元催化体系的作用机制对PX氧化过程进行了深入的剖析 ,分析了芳烃中甲基和醛基的各步氧化机理及其与催化剂循环之间的耦合作用 .在此基础上推导出关于反应物浓度的动力学模型 ,并根据实验数据计算出各动力学参数 .     

对二甲苯液相催化氧化动力学(Ⅰ)反应机理和动力学模型

针对PX高温液相催化氧化过程的特点开发了一套气液固三相反应实验技术，进行了氧化过程的动力学实验研究.根据自由基反应机理和Co-Mn-Br三元催化体系的作用机制对PX氧化过程进行了深入的剖析，分析了芳烃中甲基和醛基的各步氧化机理及其与催化剂循环之间的耦合作用.在此基础上推导出关于反应物浓度的动力学模型，并根据实验数据计算出各动力学参数.     

对二甲苯二次氧化过程中液相反应的研究

通过半连续实验考察了对二甲苯(PX)二次氧化过程中的液相氧化,并对该过程进行了模拟计算。设计和进行了包含PX液相氧化、中断反应以及降温二次液相氧化三个阶段的实验;通过动力学实验测定和数据回归确定了基于芳烃氧化自由基链式反应机理的PX液相氧化动力学模型的参数;采用建立的PX液相氧化机理模型对PX分段氧化过程进行了预测。结果表明,对中断反应后的降温二次液相氧化间歇过程,采用第一阶段末期自由基浓度做初值时模型预测值与实验值符合良好;而假设自由基初值浓度为零时,PX液相氧化动力学模型对二次氧化的液相反应预测效果较差,其原因可能是中断降温后的氧化母液中存在过氧基团会使二次液相氧化反应极快地被再引发启动。     

PX氧化反应动力学模型研究

建立了一套半连续的PX高温催化氧化反应动力学实验装置,并进行了相关的动力学研究。依据实验数据和机理分析,提出了反应组分抑制的动力学模型。     

对二甲苯液相催化氧化动力学(Ⅲ)催化剂配比与浓度的影响

对二甲苯(PX)高温液相催化氧化过程采用Co-Mn-Br三元复合催化剂,对该催化体系的机理作了深入探讨,针对催化剂总浓度、溴浓度以及钴锰配比对主反应的影响规律进行了系统的动力学实验,获得了各步反应速率随催化剂浓度与配比的变化关系.研究发现,在实验所考察的温度与催化剂组成条件下该催化体系存在一最佳钴锰配比（1∶1）,溴浓度和催化剂总浓度对反应速率都有显著的影响,其中以溴浓度最为敏感.     

环已烷液相氧化反应动力学研究进展

本文对环己烷液相催化或无催化氧化制KA油,环己烷均相或非均相一步氧化制己二酸的反应机理、动力学模型及传质与动力学之间的关系进行了综述。最后指出,我国应加强对环己烷液相氧化反应,尤其是反应动力学和传质过程的研究和开发,为我国尼龙66生产装置的完全国产化作必要的技术贮备。同时,对非均相氧化的研究也应引起重视。     

“PX氧化反应特性及模型化”项目通过鉴定

为实现 PTA生产技术的国产化 ,从 1 998年7月开始 ,仪征化纤公司和浙江大学联合进行精对二甲苯 (PX)氧化反应特性及模型化的研究开发。把 PX制 PTA的氧化反应动力学和氧化过程技术开发确立为核心技术开发 ,经过两年多的研究 ,成功开发出一套新颖、可靠的 PX高温氧化动力学实验装置 ,较好地解决了实验装置的条件控制 ,取样方法 ,样品分析测试等 3个方面的技术难题 ,获得相应动力学方程的有关基础数据 ,开发了相应的动力学模型和软件。所得结果系统可靠 ,模型与工业化数据一致 ,达到国内领先水平 ,为仪征化纤公司 PTA生产装置安全、稳定…     

对二甲苯氧化用钴锰溴铪催化体系研制

以氧氯化铪为原料,实验制备了PX氧化反应用醋酸铪、溴化铪催化剂;并在PX氧化性能实验装置中评价了催化剂性能,比较了醋酸铪、溴化铪所形成钴锰溴铪催化剂的性能及铪浓度对催化性能的影响;实验表明醋酸铪与溴化铪的性能相当,铪浓度增加,反应速度加快,铪对PX氧化反应各步的催化幅度不同,在工业生产条件下,加入60μg/g铪,PX消失速度增加了36%,关键组分PT酸速度增加了7%。     

甲苯液相催化氧化反应动力学

采用一套可无级调速的玻璃搅拌釜气液相反应器,通过改变搅拌速率考察了传质对甲苯液相氧化反应的影响,考察结果表明搅拌速率达到700 r/min时可基本排除传质的影响.在不同反应温度下进行了甲苯液相催化空气氧化的动力学实验研究,得到了反应物甲苯和主要反应产物苯甲酸、苯甲醛、苯甲醇和苯甲酸苄酯的浓度随反应时间变化的数据.在已有动力学研究的基础上,根据甲苯及其主要产物的情况,提出了甲苯液相氧化的反应网络和分子反应机理,建立了相应的动力学模型.根据实验数据回归获得了动力学模型参数,动力学模型计算与实验数据吻合良好,甲苯氧化生成苯甲酸反应的活化能为49.4 kJ/mo.     

2,6-二甲基萘催化氧化制备2,6-萘二甲酸动力学

研究了Co-Mn-Br催化体系下,2,6-二甲基萘液相氧化制备2,6-萘二甲酸的动力学规律,分析了各中间产物,建立了氧化反应网络,提出了双曲型反应动力学模型。考察了反应物浓度,温度和催化剂含量对反应速率的影响,并依据实验数据拟合出动力学参数和各步反应的活化能。结果表明,双曲型的动力学模型能够较好地描述反应过程,计算结果与实验数据吻合良好。2,6-二甲基萘液相氧化为典型串联反应过程,两个甲基依次先后氧化为醛和酸,其中2-甲酰基-6-萘酸生成2,6-萘二甲酸的反应是整个反应的控制步骤。     

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。