中间体与精细化工文摘

甲醛溶液中甲醇回收技术研究 吉化公司为了确保巴斯夫-吉化新戊二醇原料质量要求(甲醇溶液中甲醇质量分数必须小于3％),在继续使用浮石-银催化剂生产甲醛时,采用增建一套处理能力为3万t/a脱醇塔装置。从甲醛第一吸收塔底采出的粗甲醛溶液(含甲醇7％)送入脱醇塔进行甲醇脱除,其原理是利用粗甲醛混合液中各组分挥发度不同,将甲醛与     

产品无醇甲醛在尿素、硝铵成品检验中的应用

甲醛法测定氨态氮含量时,所用甲醛中甲醇含最大于1％必将导致结果偏低。因此,在尿素国家标准GB2442-81、硝酸铵国家标准GB2945-82中,规定了甲醛法测定总氮含量时,应将市售含甲醇12％的试剂甲醛进行蒸馏,降低甲醇含量,配制成甲醇小于1％的25％甲醛溶液;或者将市售固体多聚甲醛在碱性溶液中加热解聚来制取。太原化学工业公司化肥厂生产的甲醛溶液中甲醇含量小于0.02％,据称这种25％无醇甲     

甲缩醛合成催化剂的筛选和工艺条件

针对由甲醇、甲醛溶液合成甲缩醛反应。采用不同制备方法制备了四种不同组成的硅酸铝固体酸催化剂,在间歇操作方式下,通过改变催化剂用量、反应温度、原料甲醇和甲醛的摩尔配比以及反应原料中甲醛初浓度.考察了反应混合物中反应物和产物浓度随时间的变化关系以及反应的选择性和收率,得出了实验操作范围内适宜的催化剂组成、制备方法和反应工艺条件。     

水洗在甲醛生产过程中的作用

前言。在甲醛生产过程中，空气是一种必不可少的物质，甲醛生产中，空气是氧气的主要来源，甲醇在催化剂的作用下与氧气发生脱氢氧化还原反应而生成甲醛气体。甲醛气体在冷却吸收的条件下形成工业甲醛溶液（一般含量为37％）。空气质量的好坏，直接影响了甲醛生产过程中触媒（电解银法和铁钼法）的活性和使用寿命，催化剂活性直接影响了生产过程中产品质量以及消耗的高低，也就是生产成本的高低。我公司十年来对此进行了尝试和实践。现向同行们作一点体会性的汇报。     

工业甲醛的气相色谱分析方法

工业甲醛的气相色谱分析方法叶福祥（南京市大厂镇南化公司氮肥厂南京市大厂镇２１００３５）工业甲醛纯度的分析一般采用酸碱滴定法，甲醛中酸含量采用密度测量法Ｏ由于醛、醇含量与密度三者互相制约，对含甲醇超过一定范围的甲醛溶液就无法使用该法测定。我们采用气团色...     

甲醇为初始反应原料连续制备聚甲氧基二甲醚的系统

正本发明公开了一种甲醇为初始反应原料连续制备聚甲氧基二甲醚的系统,主要包括甲醛制备单元、甲缩醛制备单元和聚甲氧基二甲醚制备单元:甲醛制备单元的主要作用是在催化剂的作用下,把原料甲醇氧化成甲醛溶液;甲缩醛制备单元的作用是固体酸性树脂催化剂的作用下,把部分甲醛溶液与甲醇反应,制备成甲缩醛;聚甲氧基二甲醚制备单元的作用是在离子液体催化剂的作用下,甲醇、甲缩醛分别与甲醛溶液的缩合反应,制备聚甲氧基二甲醚,反应产物经过分离提纯后,得到聚甲氧基二甲醚产品。     

某化工厂化学危害与防护教学案例分析

以生产甲醛溶液的化工厂为例，分析其生产过程主要存在甲醇、甲醛等化学危害和火灾爆炸危险，结合检测结果及其所采取的防护设施、管理措施等现场调查情况进行分析与评价，就发现的不足之处提出建议：完善应急预案，补充完善职业病危害告知卡等现场告知内容等，以进一步提高安全生产管理水平和工人的职业病防护意识，满足相关标准规范的要求。以甲醛溶液生产项目为例，为化工行业的职业危害及其防护措施的分析与评价提供教学案例参考。     

多聚甲醛制备无水甲醛溶液的研究进展

本文介绍了无水甲醛溶液的生产方法、性质以及作为甲醛源在有机合成领域的应用,综述了近年来国内外多聚甲醛解聚制无水甲醛溶液工艺的研究进展,以期为无水甲醛的进一步研究发展提供参考.指出以无水甲醛溶液替代固体多聚甲醛作为有机合成反应的甲醛源,是今后工业生产重要的研究方向.     

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%）。     

改进生产条件 降低甲醛中的醇含量

介绍了巨化公司在甲醛生产中开展的以提高甲醇转化率，降低甲醛中甲醇含量，提高经济效益及保障季戊四醇正常生产目的的质量攻关活动。通过对生产工艺中诸因素的正交试验，优化节生产条件，结果使甲醛中甲醇含量自原来的平均７％降低到２％左右，获得较显著的经济效益和社会效益。     

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。