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淀粉与丙烯酰胺的接枝共聚 总被引:6,自引:0,他引:6
本文研究了在硝酸铈铵作用下,淀粉和丙烯酰胺接枝共聚合的反应规律,探讨了引发剂浓度、单体浓度、pH值、反应时间和反应温度对接枝聚合的影响,并对不同的引发体系引发淀粉—丙烯酰胺接枝聚合进行了比较,结果表明,以硝酸铈铵引发的淀粉—丙烯酰胺接枝聚合所产生的均聚物少,引发效率高。 相似文献
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焦磷酸锰(Mn^3+)络阴离子引发淀粉与丙烯酸酯接权共聚的研究 总被引:3,自引:0,他引:3
以廉价无毒的Mn^3+作为引发剂引发丙烯酸酯淀粉接枝共聚,重点研究了引发剂浓度,单体浓度,反应温度及反应时间对淀粉接枝丙烯酸乙酯的影响规律。 相似文献
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焦磷酸锰(Mn~(3 ))络阴离子引发淀粉与丙烯酸酯接枝共聚的研究 总被引:4,自引:0,他引:4
以廉价无毒的Mn3+作为引发剂引发丙烯酸酯与淀粉接枝共聚,重点研究了引发剂浓度、单体浓度、反应温度及反应时间对淀粉接枝丙烯酸乙酯的影响规律。结果表明,单体转化率均可达95%,接枝效率和接枝率最高分别可达60%和170%,接枝物分子量在1.0×105~2.5×105,接枝频率在1100左右 相似文献
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玉米淀粉/丙烯酰胺接枝型高吸水性树脂的合成 总被引:9,自引:1,他引:8
本文以硝酸铈铵为引发剂 ,研究了单体浓度、引发剂浓度、反应温度和反应时间等因素对玉米淀粉与丙烯酰胺接枝共聚制备高吸水性树脂的影响 ,通过反应条件和正交试验 ,确定了最适宜的反应条件和工艺路线 ,制备出了吸水率在 4 5 0~ 70 0g·g-1的玉米淀粉接枝型高吸水性树脂。 相似文献
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两种不同引发剂在木薯淀粉接枝丙烯酸反应的研究 总被引:9,自引:0,他引:9
详细地研究了淀粉接枝丙烯酸反应过程中 ,两种不同的引发剂过硫酸钾 -亚硫酸氢钠和硝酸铈铵在淀粉接枝丙烯酸共聚反应的影响 ,对一些反应条件如引发剂浓度、反应的温度、单体的浓度、单体的中和度、反应的时间等进行了单因素试验 ,以接枝率 ,单体转化率 ,接枝效率为主要考查目标 ,从而得出试验的最佳条件。在过硫酸钾-亚硫酸氢钠的引发下 ,最佳的反应条件是 :反应温度 35℃ ,引发剂的浓度是 2 .8m mol/· L- 1 ,丙烯酸的浓度是1.1mol· L- 1 ,反应时间 3h,中和度为 80 % 相似文献
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采用廉价无毒的焦磷酸锰(Mn^3+)络离子作为引发剂,以十二烷基硫酸钠为乳化剂,对淀粉与苯乙烯及二元单体接枝共聚进行了初步探索,研究了单体浓度,引发剂浓度,反应温度及反应时间对接枝反应的影响趋势,发现Mn^3+具有良好的引发效果,接枝效率在65%~90%,接枝率可达200%,对淀粉与St/AN,St/EA二元单体接枝共聚的研究表明接枝效率不高。 相似文献
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反相乳液法淀粉丙烯酰胺接枝共聚反应的研究 总被引:22,自引:4,他引:22
以木薯淀粉为主要原料,研究了淀粉/丙烯酰胺单体/乳化剂/油/水反相乳液体系的接枝共聚反应规律,考察了反应温度、引发剂和乳化剂浓度、淀粉单体比、油水比等因素对淀粉接枝丙烯酰胺共聚反应过程的影响,并对反应机理进行了探讨.结果显示:在本实验考察范围内引发剂浓度、单体淀粉比、反应温度影响显著;乳化剂用量和油水比对反相乳液体系的形成及稳定有重要的影响;淀粉与亲水性单体丙烯酰胺的接枝共聚反应为淀粉团粒表面控制. 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