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1.
介绍了国外顺丁橡胶聚合系统、凝聚系统和后处理系统等技术进展,并针对国内外差距,对我国顺丁橡胶的发展提出了建议。  相似文献   

2.
介绍了稀土顺丁橡胶的性能特点和聚合特点,分析了国内外稀土顺丁橡胶的生产现状,提出了我国今后发展稀土顺丁橡胶的建议。  相似文献   

3.
调节镍系顺丁橡胶分子量的研究   总被引:3,自引:0,他引:3  
研究了改变聚合工艺条件及加入分子量调节剂D、C对顺丁橡胶分子量的调节作用,结果表明:Ni-Al-B体系中改变聚合工艺条件不能大幅度调节顺丁橡胶的分子量,加入分子量调节剂D可以大幅度调节顺丁橡胶的分子量;加入分子量调节剂C可以降低顺丁橡胶的分子量。  相似文献   

4.
回顾了Ni系催化剂的开发研究及应用。重点介绍Ni系催化剂合成顺丁橡胶的聚合特征,活性中心模型,聚合机理,聚合动力学,以及国内外改进Ni系催化剂的新进展。  相似文献   

5.
介绍了顺丁橡胶装置丁二烯回收单元的技术改造情况,改造后回收了放火炬燃烧的1.3-丁二烯,其收率可达85%,回收的1,3-丁二烯的质量满足设计要求,并可直接作为顺丁橡胶聚合的单体。  相似文献   

6.
主要介绍了近年来国内外聚异丁烯的生产现状及科研情况;对国内外主要厂家生产聚异丁烯的工业生产技术进行了详细的分析。并针对以上几种生产技术的特点进行了对比;另外,还较全面地论述了BF3引发异丁烯聚合反应原理。阐述了异丁烯聚合过程中主要工艺参数对聚合结果的影响,并提出了异丁烯聚合的较佳的工艺参数;最后,针对我国聚异丁烯生产的具体情况提出了作者的几点建议。  相似文献   

7.
顺丁橡胶的高性能化   总被引:3,自引:0,他引:3  
介绍了近年来采用新的聚合催化剂,化学改性方法以及链端导入官能团的改性技术在提高顺丁橡胶性能方面的研究进展。  相似文献   

8.
顺丁橡胶生产工艺及展望   总被引:2,自引:0,他引:2  
介绍了镍系顺丁橡胶生产的工艺,催化剂陈化方式,比较了国内外生产工艺的不同及差距;提出对镍系顺丁橡胶生产的建议。  相似文献   

9.
介绍了十年来制备聚碳酸酯工艺的发展情况。近年来,GE、Bayer和Asahi/Chi Mei等公司已开始利用非光气技术(也称为熔融工艺)进行工业化生产聚碳酸酯。简要介绍了传统的界面聚合工艺和非光气技术制备聚碳酸酯的情况。介绍了碳酸二苯酯与双酚A聚合制备聚碳酸酯的酯交换或熔融聚合方法,并概述了3种制备碳酸二苯酯的生产工艺(包括直接和非直接生产技术),  相似文献   

10.
改进聚合技术提高生产强度和产品质量   总被引:1,自引:0,他引:1  
介绍了上海氯碱化工股份有限公司对127m^3聚合釜生产PVC的工艺进行改进的情况,改进了防粘釜技术及水洗操作过程,采用NH4HCO3作为pH值调节剂,并使用了高效引发剂TX-99,缩短了聚合时间,提高了聚合釜的生产强度。  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   

13.
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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15.
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   

19.
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   

20.
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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