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1.
无溶剂光氯化悬浮法制备低氯化度的氯化等规聚丙烯   总被引:4,自引:0,他引:4  
叶庆国  杨秀英 《精细化工》2000,17(7):388-390,412
用无溶剂光氯化悬浮法进行等规聚丙烯 (IPP)氯化反应 ,考察了反应时间、引发剂、通氯量、悬浮剂和金属盐等因素对氯化速度的影响 ,以偶氮二异丁腈为引发剂 ,m(IPP)∶m(H2 O) =1∶1 5,通氯量为 40mL min ,反应时间 1 0h ,可得到氯质量分数在 2 5%左右的氯化聚丙烯。金属离子可明显缩短其诱导期 ,但反应后期 ,金属离子的存在对氯化反应起抑制作用。  相似文献   

2.
氯化聚丙烯改性及其粘附性能研究   总被引:4,自引:0,他引:4  
以甲苯为溶剂,过氧化二苯甲酰(BPO)为引发剂,通过自由基聚合,采用马来酸酐(MAH)接枝改性氯化聚丙烯(CPP),并对产物结构进行了FTIR表征。研究了反应温度、反应时间、MAH和BPO用量对改性氯化聚丙烯胶粘剂粘附性能的影响;得出较佳的工艺条件为:反应温度θ=90℃,反应时间t=3 0h,原料质量配比为m(CPP)∶m(MAH)∶m(BPO)=100∶3∶0 3。  相似文献   

3.
张瑞芹 《河北化工》2008,31(4):43-44
以工业硫磺和液氯为主要原料,直接制备二氯化硫.确定了合成反应最佳工艺条件:起始反应温度为100~110℃,氯气通入时间(即反应时间)为6 h,通氯气量为75 L/h,精制蒸馏温度为60~64℃,稳定剂三氯化磷用量为0.1%~0.3%.在此工艺条件下制备的二氯化硫收率可达82%以上.  相似文献   

4.
在原有工艺的基础上采用氯气一步法直接氯代1-硝基蒽醌生产1-氯蒽醌。首先在三口烧瓶中加入原料和以亚硫酸钠为助溶剂后开始缓慢升温当达到160℃时,原料开始融化。此时通入氯气和氮气的混合气体,保持通气2.5 h以上。结果表明此氯化反应是自由基机理,优化的工艺条件为:复合引发剂用量[n(偶氮二异丁腈)∶n(三苯基磷)=1∶1]0.2%、助熔剂亚硫酸钠用量0.5%下,反应温度160℃、混合气体[v(氯气)∶v(氮气)=70∶30]的速率为300 mL/min、反应时间为2.5 h,1-氯蒽醌的收率为90.9%;利用1-氯蒽醌易升华的特点,提纯1-氯蒽醌可使其含量在99.5%以上。  相似文献   

5.
反式-1,4-聚异戊二烯的氯化改性   总被引:4,自引:0,他引:4  
采用水相悬浮法,在常压下对反式-1,4-聚异戊二烯(TPI)进行氯化改性。研究了温度、时间、粒径等对氯化反式-1,4-聚异戊二烯(CTPI)氯含量的影响。得到适宜的反应条件是:采用两阶段升温的方法,控制一定的通氯量,第一阶段,反应温度为35℃,反应时间为2~3h;第二阶段.反应温度为50~55℃,反应时间为1~6h,可获得氯质量分数在50%以内的CTPI,产品为可溶解的白色疏松颗粒。  相似文献   

6.
采用搅拌式固相法制备氯化等规聚丙烯(CIPP),讨论了不同的温度控制方式对等规聚丙烯氯化反应的影响。结果表明,在恒定的温度条件下,100~103℃是较好的反应温度,温度过低产物的氯分布不均匀,温度过高容易发生脱氯化氢现象。在热处理方式下,由于气-固相反应特有的烧结和粘结影响严重,不利于氯化反应的进行。逐步长温的控温方式是制备CIPP的最佳温度控制方式。  相似文献   

7.
聚丙烯水相悬浮热氯化   总被引:2,自引:0,他引:2  
研究了等规聚丙烯(IPP)水相悬浮热氯化,考察了氯化时间和温度、IPP粒径、搅拌转速、通氯速率等条件对氯化反应的影响。发现氯含量随氯化温度的升高而增大,随IPP粒径的减小而呈线性增大;在IPP充分分散条件下搅拌和通氯速率对氯化几无影响。扫描电镜(SEM)照片显示,氯化反应首先发生在粒子表面,氯化产物将粒子表面孔隙填充,增加了氯向粒子内部扩散的阻力,致使粒子内部的氯化反应缓慢。  相似文献   

8.
研究了制备工艺条件、原料性质等对氯化等规聚丙烯溶解性能的影响。结果表明 ,选择适当的控温方式制得氯分布均匀的CIPP溶解性较好 ;原料熔融指数高的等规聚丙烯原料制得的CIPP产品溶解性较好 ;原料颗粒粒度和含氯量对产物CIPP的溶解性能影响显著  相似文献   

9.
氯化-3-氰-2-羟丙基三甲胺的合成   总被引:1,自引:2,他引:1  
研究了氯化 3-氯 - 2 -羟丙基三甲胺 ( CHPTMA)氰化反应生成氯化 3-氰 - 2 -羟丙基三甲胺的工艺 ,得到了最佳工艺条件 :反应温度 40~ 45°C,反应时间 1 .5 h,物料配比 n( CHPTMA) ∶ n( Na CN) 为 1∶1 .0 5。在此条件下 ,产率为 78.8%。  相似文献   

10.
无水稀土氯化铈制备工艺研究   总被引:5,自引:0,他引:5  
研究了在氩气气氛下用氯化铵作为氯化剂氯化氧化铈制备高纯无水稀土氯化铈的工艺条件,通过正交实验考察了物料配比、反应温度、反应时间的影响,并用XRD对无水稀土氯化铈进行了表征. 结果表明,氯化铈的最佳制备工艺条件为:物料摩尔比n(NH4Cl):n(CeCl4)=12:1,氯化焙烧温度300℃左右,氯化时间30 min. 此条件下氯化率为96.16%,产物含杂量小于5%.  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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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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