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钠基蒙脱土经过一次插层有机改性和二次插层有机改性后制得有机改性蒙脱土,作为催化剂用于催化不饱和脂肪酸二聚化反应制备二聚酸。采用XRD、SEM、TEM、FTIR和TG等检测手段对有机改性后蒙脱土的内层结构和性质进行分析。实验表明改性后蒙脱土层间距由1.48 nm扩大到3.82 nm,而且保持原来的夹心结构不变。蒙脱土的表面形貌和内部结构发生改变,表面变得疏松,内部层间距扩大且插层剂含量增加,分散实验表明二次插层有机改性蒙脱土在不饱和脂肪酸中分散性能优异。相同条件下,二次插层有机改性蒙脱土催化不饱和脂肪酸二聚化反应,二聚酸产率75.33%,是未改性蒙脱土催化制得二聚酸产率的2.14倍,并通过FTIR、1H NMR和LC-MS证实合成的产物为二聚酸。 相似文献
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分别利用阳离子表面活性剂十六烷基三甲基氯化铵(CTAC)和阴离子表面活性剂十二烷基磺酸钠(SDS)制备了有机蒙脱土,并通过FTIR和XRD对其结构进行表征,发现CTAC的插层效果明显优于SDS。研究中考察了体系反应温度、pH值对蒙脱土插层效果的影响。结果表明,以CTAC为插层剂,反应时间为1 h,反应温度为80℃,体系pH值为7时,制得的有机蒙脱土其d001值达1.962 nm,层间距最大。 相似文献
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《化工学报》2017,(Z1)
钠基蒙脱土经过一次插层有机改性和二次插层有机改性后制得有机改性蒙脱土,作为催化剂用于催化不饱和脂肪酸二聚化反应制备二聚酸。采用XRD、SEM、TEM、FTIR和TG等检测手段对有机改性后蒙脱土的内层结构和性质进行分析。实验表明改性后蒙脱土层间距由1.48nm扩大到3.82nm,而且保持原来的夹心结构不变。蒙脱土的表面形貌和内部结构发生改变,表面变得疏松,内部层间距扩大且插层剂含量增加,分散实验表明二次插层有机改性蒙脱土在不饱和脂肪酸中分散性能优异。相同条件下,二次插层有机改性蒙脱土催化不饱和脂肪酸二聚化反应,二聚酸产率75.33%,是未改性蒙脱土催化制得二聚酸产率的2.14倍,并通过FTIR、1 H NMR和LC-MS证实合成的产物为二聚酸。 相似文献
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二聚阳离子表面活性剂改性蒙脱土的制备和表征 总被引:4,自引:0,他引:4
合成了二聚阳离子表面活性剂GeminiC12,用核磁共振氢谱(1HNMR)表征了它的结构,并用它作为有机插层剂应用于蒙脱土的改性处理。红外光谱(FTIR)、热重分析(TGA)表明,GeminiC12已插层到蒙脱土片层间。X射线粉末衍射(XRD)表明,插层后蒙脱土层间距从1 19nm增加到3 8nm,是十六烷基三甲基溴化铵(CTAB)处理效果的两倍。沉降实验表明,改性后蒙脱土在苯乙烯和石蜡中形成凝胶体系,表现出很好的相容性和分散性,这种改性效果优于目前常用的CTAB处理效果,更有利于聚合物或其单体进入蒙脱土层间形成纳米复合材料。 相似文献
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表面活性剂和硅烷偶联剂有机复合改性蒙脱土的制备及性能表征 总被引:1,自引:0,他引:1
为增加蒙脱土与有机物的相容性,采用十六烷基三甲基溴化铵(CTAB)与硅烷偶联剂(KH-560)对蒙脱土进行了有机复合改性。X-射线衍射和红外光谱的结果表明,CTAB已插入蒙脱土片层,平均层间距离从1.54 nm增大到3.98 nm和2.08 nm,而KH-560未插入蒙脱土片层,只是覆盖在蒙脱土表面,未改变蒙脱土的插层结构;分散性实验表明,表面活性剂和硅烷偶联剂有机复合改性的蒙脱土在苯乙烯、液体石蜡中的分散性好于其他改性蒙脱土;有机复合改性不仅增大了蒙脱土层间距,且改善了蒙脱土与聚氯乙烯的界面效果,提高了蒙脱土在聚氯乙烯基体中的分散均匀性,从而使聚氯乙烯/蒙脱土复合材料玻璃化转变温度的提高和力学性能的改善更明显。 相似文献
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M. S. J. Simmonds W. M. Blaney F. Delle Monache M. Marquina Mac-Quhae G. B. Marini Bettolo 《Journal of chemical ecology》1985,11(12):1593-1599
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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Cheng-Le Zhao Shane Porzio Alan Smith Haiyan Ge H. T. Davis L. E. Scriven 《Journal of Coatings Technology and Research》2006,3(2):109-115
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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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. 相似文献
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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
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中蓝晨光化工研究院有限公司《塑料工业》编辑部 《塑料工业》2009,37(3)
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
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中蓝晨光化工研究院《塑料工业》编辑部 《塑料工业》2007,35(3):1-25,67
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