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1.
采用稀土催化体系Nd(F_3CO_2)_3-BrC_5H_(11)-R_mAlH_(3-m)(Nd-Br-Al),以甲苯为溶剂,在50℃恒温水浴中进行苯乙烯(St)和异戊二烯(Ip)共聚合。结果表明,由Al(Oct)-3组成的催化体系可制备以顺式-1,4结构为主的共聚物;在后者组成的催化体系中,当Al/Nd=5(摩尔比,下同),Br/Nd=5时,聚合活性最高。经IR,NMR检测表征了共聚物的微观结构。同时,用π-烯丙基型配位机理和返扣配位机理对实验结果进行了定性解释。  相似文献   

2.
采用稀土催化体系Nd(F3CO2)3-BrC5H11-RmAlH3-m(Nd-Br-Al),以甲苯为溶剂,在50℃恒温水浴中进行苯乙烯和异戊二烯共聚合。结果表明,由Al(Oct)3或Al(i-Bu)3组成的催化体系可制备以顺式-1,4结构为主的共聚物,在后者组成的催化体系中,当Al/Nd=5(摩尔比,下同),Br/Nd=5时,聚合活性最高。经IR,NMR检测表征了共聚物微观结构。同时,用π-烯丙基  相似文献   

3.
混凝法处理高浊度水   总被引:13,自引:2,他引:13  
研究了单独使用Al2(SO4)3.18H2O,无水AlCl3,KAl(SO4)2.12H2O,FeSO4.7H2O,Fe2(SO4)3.xH2O,FeCl3.6H2O混凝剂和用无机铝盐(铁盐)与聚丙烯酰胺(PAM)联合处理高浊度水的混凝性能。研究表明,使用无机混凝剂和有机高分子混剂复合处理的混凝效果优于单独处理,且前者的投药顺以混凝效果和再稳作用有影响,以先加无机混凝剂,后加有机高分了混凝剂时的效  相似文献   

4.
乳酸酯化催化剂比较   总被引:2,自引:0,他引:2  
李汝珍  苏涛 《广西化工》1999,28(3):35-37
用FeCl3、SnCl2、SnCl4、NiCl2、AlCl3、CrCl3、H2SO4、CuSO4、ZnSO4、强酸性离子离子交换树脂,固体 强酸在〈100℃及元搅拌下进行的乳酸和乙醇催化酯化反应实验,结果表明各种不同均相催化剂催化的反应液中乳酸乙酯含量最低值为最高的72%左右。相对而言效果最好的依次为H2SO4,SnCl4、AlCl3等。  相似文献   

5.
研究了以高锰酸钾或重铬酸钾/水/浓硫酸=5∶8∶100(质量比)或20%(质量分数)的过硫酸铵水溶液及氯化铁或硫酸铜作为催化剂对聚烯烃进行的表面氧化处理,并通过熔点和红外光谱及光电子能谱等方法对氧化反应和产品的结构进行了表征。研究表明,最佳氧化温度和时间分别为45℃~60℃与45min;用KMnO4/H2SO4/FeCl3/CuSO4,K2Cr2O7/H2SO4/FeCl3,K2Cr2O7/H2SO4/CuSO4体系对聚乙烯的氧化中,氧化深度依次减小,C原子的摩尔分数由未氧化时的80.804%,分别降低为31.907%、69.905%和78.669%;在FeCl3催化下,产品中Cl的含量普遍增加,而以KMnO4/H2SO4/FeCl3/CuSO4氧化时增加最多,但对K2Cr2O7/H2SO4/FeCl3氧化体系,O含量的增加相对较多  相似文献   

6.
合成了6种2-[2'-(6’-取代苯并噻唑)偶氮]-5-二甲氨基苯甲酸(6-R-BTAMB,其中R=CH3,OCH3,Cl,Br,CH3SO2,NO2)新试齐4。初步研究了6-CH3-BTAMB与Fe(Ⅱ)、Co(Ⅱ)、Ni(Ⅱ)、Cu(Ⅱ)和Pd(Ⅱ)等离子的络合显色反应的光度特性。  相似文献   

7.
用 Fe Cl3 、 Sn Cl2 、 Sn Cl4 、 Ni Cl2 、 Al Cl3 、 Cu Cl2 、 Cr Cl3 、 H2 S O4 、 Cu S O4 、 Zn S O4 、强酸性离子交换树脂、固体超强酸在< 100℃及无搅拌下进行的乳酸和乙醇催化酯化反应实验,结果表明各种不同均相催化剂催化的反应液中乳酸乙酯含量最低值为最高值的 72 % 左右。相对而言效果最好的依次为 H2 S O4 、 Sn Cl4 、 Al Cl3 等。  相似文献   

8.
乙酸异丁酯合成中无机盐催化作用初探   总被引:10,自引:1,他引:10  
研究了CuSO4.5H2O2、CuSO4、FeSO4、7H2O、FeCl3、6H2O、CuCl2.2H2O等5种盐对异丁醇与乙酸酯化反应的催化性能,结果表明FeCl3.6H2O和CuCl2.2H2O是较好的催化剂,酯转化率达86-93%。  相似文献   

9.
10-甲基-9-取代亚苄基-9,10-二氢吖啶类化合物是很好的感光材料[1~3],其结构式为:NH3C  RR=H(I),o-NO2(Ⅱ),m-NO2(Ⅲ),p-NO2(Ⅳ),2,4-Dinitro(Ⅴ),m-Cl(Ⅵ),p-Cl(Ⅶ),p-OCH3(Ⅷ)1 合成方法及讨论  称取2.34g(7mmol)洪埃试剂(按文献[4]制备)溶于70mLTHF中,在氮气保护下,搅拌冷却,于-78℃下加入t-BuLi的己烷悬浮液5mL(8mmol),溶液由无色变为黄色,待反应进行10min后加入溶有0.74…  相似文献   

10.
近几年开发的国外农药新品种(5)   总被引:3,自引:0,他引:3  
刘长令 《农药》1999,38(7):40-42
甲氧磺草胺(metosulam)NHSO2NNNNOCH3OCH3ClClCH3C14H13Cl2N5O4S4183中文通用名称甲氧磺草胺英文通用名称metosulam(BSI,ISO,ANSI)商品名称Eclipse;Pronto;Sansac;...  相似文献   

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12.
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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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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