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1.
萘异丙基化反应的目标产物2,6-二异丙基萘(2,6-DIPN)与主要副产物2,7-二异丙基萘(2,7-DIPN)的性质相近,经过精馏和结晶后不能完全分离。选用阳离子改性后的Y沸石分子筛作吸附剂,甲苯作脱附剂,将2,6-DIPN与2,7-DIPN进行吸附分离。实验表明:NaY和PdY分子筛对2,6-DIPN的吸附性能较强,LiY和KY对2,7-DIPN吸附性能较强;NaY吸附剂的再生性能良好。  相似文献   

2.
采用高压釜对Hβ沸石催化剂的萘异丙基化催化反应性能进行评价。系统考察了溶剂用量、异丙醇与萘的物质的量比、Hβ沸石用量、反应温度及反应时间等因素对异丙基化反应的影响,优化了反应条件。实验结果表明,合成2,6-二异丙基萘(2,6-DIPN)适宜的反应条件是:溶剂十氢萘用量25 mL·(0.05 mol-萘)-1,n(异丙醇)∶n(萘)=2.5∶1,催化剂用量15%,反应温度270 ℃,反应时间6 h,此时萘的转化率达66.41%,DIPN及2,6-DIPN的收率分别达到18.72%和3.41%,同时2,6-DIPN和2,7-DIPN的比值达到1.56。覆硅改性Hβ沸石,在基本不改变孔道性能的前提下,有效钝化其外表面酸性位,从而改善其催化萘异丙基化反应的综合性能。硅油沉积量为0.4 mL·g-1时,萘转化率81.21%,2,6-DIPN收率7.60%,2,6-DIPN与2,7-DIPN的比值保持在1.52的较高水平。  相似文献   

3.
2,6-DIPN与2,7-DIPN二元体系固液相图的测定和关联   总被引:1,自引:0,他引:1  
绘制了2,6-二异丙基萘(2,6-DIPN)与2,7-二异丙基萘(2,7-DIPN)二元体系的固液相图,测定了2,6-DIPN和2,7-DIPN二元混合物体系的低共熔点,并用理想溶液模型进行了关联。结果表明,2,6-DIPN与2,7-DIPN二元体系固液平衡相图为简单低共熔混合物相图,低共熔点温度为-19.5℃,组成为2,7-DIPN12.2%(质量分数,下同),2,6-DIPN87.8%,由试验数据拟合得到2,6-DIPN的熔化焓为4.878kJ/mol。  相似文献   

4.
Co-Mn-Br催化2,6-二异丙基萘液相氧化制2,6-萘二甲酸   总被引:1,自引:0,他引:1  
在高压反应釜中考察了操作方式、反应温度、金属催化剂浓度、溴浓度和反应压力对Co-Mn-Br液相催化氧化2,6-二:异丙基萘(2,6-DIPN)制2,6-萘二甲酸的影响。结果表明,半连续式操作方式比间歇式操作方式好。采用半连续操作方式时,较好的反应条件为185℃,2.0MPa,Co和Mn与2,6-DIPN的物质的量之比15:1,Br与Co和Mn的物质的量之比为1:5。在该反应条件下,得到淡黄色的产品,2,6-萘二甲酸收率达62.9%。  相似文献   

5.
硅胶负载的磷钨酸催化剂上萘的异丙基化反应   总被引:1,自引:0,他引:1  
以负载于硅胶(SiO2)上的磷钨酸为催化剂,在100 mL间歇式不锈钢高压反应釜中,研究了萘与异丙醇的烷基化反应。结果表明,中低负载量的磷钨酸均匀分散于SiO2孔道内,负载量超过30%则产生聚积。负载量为30%的磷钨酸由于酸性强、酸量大且均匀分散而呈现较高的活性。对该催化剂,适宜的反应温度为200℃,醇萘比为3,低浓度反应有利于选择性的提高,产物分布随时间的关系曲线表明该反应属连串反应类型,反应温度是影响2,6-二异丙基萘(2,6-DIPN)产率的主要因素。  相似文献   

6.
在1 L钛材反应釜内,采用Co-Mn-Br系催化剂对2,6-二异丙基萘(2,6-DIPN)液相氧化合成2,6-萘二甲酸(2,6-NDCA)的工艺条件进行了研究。采用反相高效液相色谱法分析2,6-萘二甲酸的纯度,考察了催化剂的量、反应温度、压力、原料的进料量、体系的含水量等因素对氧化反应结果的影响,得出了氧化反应较为适宜的操作条件;考察了在含氧气体中添加一定量的CO2和催化剂中加入Ni对氧化反应的影响,结果表明,CO2和Ni都可作为反应促进剂,明显提高产物的收率和纯度。在适宜的工艺条件下,实现了2,6-萘二甲酸的连续化生产,反应稳定后产品纯度可达到95%以上,随反应时间的延长,2,6-NDCA收率由69%提高到73%。  相似文献   

7.
采用HNO3对丝光沸石(HM)进行脱铝改性,并采用固定床反应器对其萘异丙基化反应的性能进行评价,考察了不同脱铝方式和不同Si/Al原子比对改性HM萘异丙基化性能的影响。结果表明,水蒸汽和硝酸处理的催化剂,其B酸与L酸的比例和酸强度分布可发生变化,在保持较好的萘转化率的前提下,提高了2,6-二异丙基萘(2,6-DIPN)的选择性。随着HNO3改性后HM分子筛的Si/Al原子比的增加,催化剂活性逐渐降低,稳定性提高,选择性先提高后降低。适宜的硝酸改性脱铝工艺条件为:HM沸石先经500℃、0.5h-1的空速下高温水蒸汽处理1.0h,再用1.6mol/L的HNO3溶液于45℃下处理24.0h,此时Si/Al原子比为31,2,6-DIPN的产率为7.24%。  相似文献   

8.
从β分子筛的改性入手,考察各种离子浸渍改性对β分子筛催化萘烷基化反应的影响。通过催化剂表面酸性和晶体结构等的表征,探讨不同离子改性对催化剂性能的影响规律及其改性机制。结果表明,5%的硝酸铜改性Hβ的效果较好,在保证转化率基本不变的前提下,β,β-DIPN选择性以及2,6-DIPN与2,7-DIPN的比值均有所提高,而多取代产物比例下降。酸性与BET表征结果表明,铜改性后选择性的提高是由于外表面酸性活性位的降低,同时,由于CuO对孔口有一定的修饰作用,同时拥有适度的生焦,从而使产物分布发生变化,提高了催化剂的选择性,而分子筛的有效孔径并未发生改变。  相似文献   

9.
用Co—Mn—Br系催化剂进行2,6—二异丙基萘的液相氧化   总被引:2,自引:0,他引:2  
刘淑芳 《燃料与化工》1997,28(3):179-186,151
日本NKK综合材料技术研究所以精萘高附加值化为目标,研究了用异丙基化法生成2,6-二异丙基萘(DIPN),并进一步氧化生成2,6-萘二羧酸(NDCA)的方法。今后期望将ND-CA作为高性能、多功能材料的重要原料,用作PEN、PBN液晶材料等高分子改质材料。本文介绍了以2,6-DIPN为原料进行氧化的研究结果。  相似文献   

10.
赵桂利  田正华  王沛  贾宏敏  李犇 《化工学报》2005,56(9):1694-1698
引言 萘异丙基化可得到2,6-二异丙基萘(2,6-diisopropylnaphthalene,简称2,6-DIPN),进一步空气氧化可制备2,6-萘二甲酸.后者是一种重要的高分子单体,用于合成高性能的热致性液晶高聚物和新一代聚酯聚萘二甲酸乙二酯(PEN).与通用聚酯PET相比,PEN具有更好的物理机械性能、耐热性能、气体阻隔性能和抗紫外线辐射性能等.  相似文献   

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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.  相似文献   

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14.
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.  相似文献   

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17.
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.  相似文献   

18.
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.  相似文献   

19.
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.  相似文献   

20.
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。  相似文献   

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