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1.
本文介绍了以顺丁烯二酸酐(MA)、丙烯酸(AA)、醋酸乙烯酯(VA)为单体合成的新型阻垢剂MA-AA-VA共聚物,是一种对BaSO4垢的优良阻垢剂,并确定了合成共聚物的最佳反应时间,反应温度和单体配比。  相似文献   

2.
贺献华 《江苏化工》1995,23(3):13-14
本文介绍了以顺丁烯二酸酐(MA)、丙烯酸(AA)、醋酸乙烯酯(VA)为单体合成的新型阻垢剂MA-AA-VA共聚物,是一种对BaSO4垢的优良阻垢剂,并确定了合成共聚物的最佳反应时间,反应温度和单体配比。  相似文献   

3.
乙酸乙烯酯嵌段共聚物的合成研究   总被引:3,自引:0,他引:3  
以AIBN为引发剂,用CCl4调节乙酸乙烯酯聚合制备了带三氯甲基端基的PVAc大分子引发剂(PVAc-CCl3)。以CuCl-bpy为催化剂,用PVAc-CCl3引发St,MMA和BMA等单体的ATRP聚合,得到了一系列相对分子质量可控、相对分子质量分布较窄的PVAc嵌段共聚物。  相似文献   

4.
AA-MAn-AMPS共聚物的合成及其阻垢分散性能   总被引:8,自引:0,他引:8  
首次以水为溶剂,过硫酸铵为引发剂,将丙烯酸(AA) 、马来酸酐(MAn)、2 丙烯酰氨基 2 甲基丙烷磺酸(AMPS) 按一定单体物质的量比进行共聚, 合成了系列AA- MAn- AMPS共聚物。探讨了它们对Ca3(PO4)2 的阻垢率与共聚物用量、共聚物单体物质的量比的关系,研究了共聚物在稳定锌、分散氧化铁方面的性能。结果表明:共聚物B[ n (AA)∶n(MAn)∶n(AMPS) = 70∶20∶10] 对Ca3(PO4)2 具有优良的阻垢分散性能, 当w(Ca2+) =150 ×10-6, w(PO43- )= 6×10- 6,pH=9-0,θ=50 ℃,t = 10 h,共聚物的质量分数=10×10-6 时,对Ca3(PO4)2 的阻垢率达99-45% ;共聚物G[ n(AA)∶n(MAn)∶n(AMPS) =70∶15∶15]则具有良好的稳定锌能力,当w(Zn2+)=10×10-6 ,pH=8-8~9-0,θ= 50 ℃,t = 24 h,共聚物的质量分数= 10 ×10-6 时,对Zn(OH)2 的阻垢率达74-42% 。B、G均具有较好的分散氧化铁性能。AA- MAn - AMPS共聚物可用作工业循环冷却水的阻垢分散剂。  相似文献   

5.
黄鹤  李建宗 《粘接》1997,18(2):5-8
采用氧化还原引发体系及复合乳液聚合方法,研究了环氧树脂/聚(苯乙烯-丙烯酸丁酯-甲基丙烯酸甲酯)[EP/P(St-BA-MMA)]半胶乳型互聚合物网络(Semi-LIPN)的聚合反应规律。考察了反应温度、引发剂用量、乳化剂用量、交联剂种类及用量,特别是EP含量对单体转化率及反应速率的影响。环氧树脂因含有微量双酚A,在聚合反应中同时起到了阻聚剂和缓聚剂的作用。从而使得该聚合反应较不含合成树脂(或橡胶  相似文献   

6.
从测得的竞聚率了单体链节在聚(苯乙烯-甲基丙烯酸β(甲基亚硫酰基)乙酯)中的序列分布。苯乙烯(S)或甲基丙烯酸β(甲基亚硫酰基)乙酯(M)的长序列的概率随着PSM中相应单体含量的增加而增加,对于S和M摩尔分数大致相等的PSM,单体链节的长序列分布函数值相接近,用与此结构相近的PSM合成的稀土金属络合物,其催化活性不佳,在M短序列分布和S长序列分布较高的情况下,络合物的催化活性最好,所得聚丁二烯的微  相似文献   

7.
自交联型SBS接枝共聚物的合成与粘接性能研究*   总被引:3,自引:0,他引:3       下载免费PDF全文
研究了在混合溶剂中了二烯-苯乙烯嵌段共聚物(SBS)与丙烯酸丁酯(BA)、甲基丙烯酸甲酯(MMA)及交联单体N-羟甲基丙烯酸胺(N-MAA)进行四元接枝共聚的反应条件及其产物的粘接性能。讨论了引发剂浓度、交联单体用量、单体配比、反应时间及反应温度对接枝共聚物的影响。实验确定的最佳反应条件为:引发剂BPO用量为SBS用量的1.8%—2.2%;交联单体N-MAA用量为SBS用量的16%—1.8%;BA/(BA+MMA)用量比为35%;反应时间为35—4.5h;反应温度为80—85℃。用红外光谱对接枝共聚物进行了分析鉴定。性能测试显示出该四元接枝共聚物对聚氯乙烯、SBS等难粘材料有较高的剥离强度。  相似文献   

8.
从测得的竞聚率计算了单体链节在聚[苯乙烯-甲基丙烯酸β(甲基亚硫酰基)乙酯](PSM)中的序列分布。苯乙烯(S)或甲基丙烯酸β(甲基亚硫酰基)乙酯(M)的长序列的概率随着PSM中相应单体含量的增加而增加。对于S和M摩尔分数大致相等的PSM,单体链节的长序列分布函数值相接近。用与此结构相近的PSM合成的稀土金属络合物,其催化活性不佳。在M短序列分布和S长序列分布较高的情况下,络合物的催化活性最好。所得聚丁二烯的微观结构与PSM中单体单元的分布无关。  相似文献   

9.
研究了聚[苯乙烯-甲基丙烯酸β(甲基亚硫酰基)乙酯](PSM)载体-三氯化钕(NaC13)络合物-Al(i-Bu)3体系催化丁二烯聚合的活性与PSM转化率和PSM·NdCl3络合物组成的关系。实验结果表明,PSM转化率为18.1%~53.4%,对PSM·NdCl3-Al(i-Bu)3体系的活性基本上无影响。低功能团含量的PSM·NdCl3络合物的活性优于高功能团含量的PSM·NdCl3。该络合物中Nd含量为4.5×10(-4)mol/g左右时,体系的催化活性最佳。体系的活性随引入的Lewis酸的种类和用量的不同而改变。  相似文献   

10.
MA-AMPS-AMPP共聚物的合成及其阻垢效果   总被引:21,自引:3,他引:18  
以水为溶剂,过氧化物为引发剂,马来酸酐(MA)、2-丙烯酰胺-2-甲基丙基磺酸(AMPS)、2-丙烯酰胺-2-甲基丙基膦酸(AMPP)为单体合成了三元共聚物。探讨了该共聚物的阻垢效果及以聚合率与单体配比、引发剂用量和组成、反应温度、时间等之间的关系,并考察了水质条件变化对共聚物阻垢性能的影响。结果表明,该共聚物具有很好的阻CaCO3垢和Ca3(PO4)2垢能力。  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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