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1.
以过硫酸铵、亚硫酸氢钠作为引发剂,N,N’-亚甲基双丙烯酰胺作为交联荆,将木薯淀粉与丙烯酰胺、丙烯酸在水溶液中接枝共聚,合成了高吸水性树脂。单因素实验结果表明,反应温度、引发剂用量、交联剂用量、丙烯酸中和度.丙烯酰胺用量对产品的吸水倍率影响较大。正交实验结果表明:适宜的接枝共聚条件为反应温度50℃,引发剂用量0.6%,交联剂用量0.04%,丙烯酸中和度85%,丙烯酰胺用量20%。  相似文献   

2.
本研究采用硝酸铈铵为引发剂,以N,N’-亚甲基双丙烯酰胺作为交联剂,合成了淀粉与丙烯酰胺接枝共聚的吸水性树脂,探讨了交联剂、引发剂、单体与淀粉配比、碱用量等因素对吸水性树脂吸水倍率的影响,得到了最优的工艺条件。  相似文献   

3.
水溶液聚合小麦淀粉接枝丙烯酸高吸水性树脂的研究   总被引:1,自引:0,他引:1  
以小麦淀粉与丙烯酸为原料,以N,N′-亚甲基双丙烯酰胺为交联剂,过硫酸铵为引发剂,采用水溶液聚合法合成高吸水性复合树脂。考察了丙烯酸的中和度、淀粉/单体比例、引发剂、交联剂等对聚合反应和树脂性能的影响。通过正交试验优选出物料的最佳配比:丙烯酸的中和度为90%,引发剂用量为0.5%,交联剂用量为0.05%,淀粉含量为10%。制备得到的吸水性复合树脂吸水率达1060g.g-1,性能优于聚丙烯酸钠高吸水性树脂。  相似文献   

4.
淀粉接枝丙烯酸/丙烯酰胺影响因素的研究   总被引:1,自引:0,他引:1  
汪娟  任皞 《山东化工》2009,38(3):19-22
探索了以过硫酸钾为引发剂,以N,N,-亚甲基双丙烯酰胺为交联剂,将淀粉与丙烯酰胺、丙烯酸在水溶液中聚合制备高吸水性树脂。结果表明:当m(丙烯酰胺):m(丙烯酸)为1:24,单体总用贵为12g,反应温度30%,反应时间2h,丙烯酸中和度94%,引发剂用量0.02g,交联剂用量为0.0015g时,可以合成具有较好的吸水性的高吸水性树脂,在蒸馏水中吸水倍率可达699.99g/g。  相似文献   

5.
丙烯酸系高吸水性树脂的合成研究   总被引:1,自引:0,他引:1  
本实验运用溶液聚合法,采用丙烯酸,氢氧化钠作为主要反应试剂,并添加过硫酸铵(引发剂);亚硫酸氢钠(还原剂);N,N-亚甲基双丙烯酸酰胺(交联剂)制取丙烯酸类高吸水性树脂,并研究了引发剂用量、还原剂用量、交联剂用量、活性炭用量、中和度、起始温度这六个因素,进行六组测定蒸馏水吸水速率的实验,找出最优条件。  相似文献   

6.
淀粉接枝丙烯酰胺与丙烯酸的实验研究   总被引:3,自引:0,他引:3  
在氮气保护下,以N,N’-亚甲基双丙烯酰胺为交联剂,过硫酸铵和亚硫酸钠作为引发剂,淀粉与丙烯酰胺、丙烯酸接枝共聚。经干燥后制备吸去离子水迭700倍的吸水性树脂。探讨了反应时间、交联剂用量、引发剂用量、单体中和度、反应温度、淀粉用量、干燥温度对吸水倍率的影响。  相似文献   

7.
二元共聚高吸水性树脂的合成与溶涨性能   总被引:39,自引:5,他引:34       下载免费PDF全文
以N ,N′-亚甲基双丙烯酰胺为交联剂 ,过硫酸钾为引发剂 ,采用溶液聚合法合成了丙烯酸 -丙烯酰胺二元共聚高吸水性树脂 .研究了单体组成、单体浓度、引发剂用量、交联剂用量、反应温度等因素对产物性能的影响 .并对反应动力学和共聚物的溶涨动力学进行了探讨  相似文献   

8.
李海虹  戴晓慧 《化学世界》2012,53(6):342-345,349
以丙烯酸,硅藻土为原料,过硫酸铵为引发剂,N,N’-亚甲基双丙烯酰胺为交联剂,通过接枝壳聚糖制备了壳聚糖-硅藻土-聚丙烯酸高吸水性树脂,并对高吸水性树脂的结构进行了红外光谱的表征,系统研究了引发剂、交联剂、硅藻土的用量,丙烯酸与壳聚糖的质量比,丙烯酸的中和度,反应温度以及反应时间对高吸水性树脂吸水率的影响。实验结果表明,丙烯酸与壳聚糖的质量比为12∶1,硅藻土的含量为1%,引发剂和交联剂的用量分别为2.5%和0.16%,中和度为70%,反应温度为60℃,反应时间为5.5h时,合成的壳聚糖-硅藻土-聚丙烯酸高吸水性树脂吸水(盐)率最高,分别为145g/g和30g/g。  相似文献   

9.
以木薯淀粉、硅藻土、丙烯酸为原料,N,N’-亚甲基双丙烯酰胺为交联剂,过硫酸铵为引发剂,通过水溶液聚合法制备了木薯淀粉-硅藻土-丙烯酸复合高吸水树脂。分别对引发剂用量、交联剂用量、丙烯酸与淀粉的摩尔比、中和度、硅藻土用量进行单位因素实验和正交实验,并通过极差分析对影响材料吸水率的因素做统计分析。最佳的反应工艺条件为:以丙烯酸单体质量为基准,引发剂用量0.55%,交联剂用量0.06%,丙烯酸与淀粉摩尔比10.5,中和度75%,硅藻土用量18%。在此条件下合成的木薯淀粉-硅藻土-丙烯酸高吸水性树脂吸水、吸盐率分别为912 g/g,94 g/g。  相似文献   

10.
通过正交实验方法,以N,N′-亚甲基双丙烯酰胺(MBA)作交联剂,过硫酸铵作引发剂,将部分中和的丙烯酸和丙烯酰胺聚合制备高吸水性树脂,考察了引发剂用量、交联剂用量、丙烯酰胺用量和中和度对树脂吸水性能的影响,所得高吸水性树脂吸水可达1297g/g,吸0.9%的盐水90g/g。  相似文献   

11.
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   

12.
It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.  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   

18.
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   

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.
Inorganic/organic hybrid materials have considerable promise and are beginning to become a major area of research for many coating usages, including abrasion and corrosion resistance. Our primary approach is to prepare the inorganic phase in situ within the film formation process of the organic phase. The inorganic phase is introduced via sol-gel chemistry into a thermosetting organic phase. By this method, the size, periodicity, spatial positioning, and density of the inorganic phase can be controlled. An important aspect of the inorganic/organic hybrid materials is the coupling agent. The initial task of the coupling agent is to provide uniform mixing of the oligomeric organic phase with the sol-gel precursors, which are otherwise immiscible. UV-curable inorganic/organic hybrid systems have the advantages of a rapid cure and the ability to be used on heat sensitive substrates such as molded plastics. Also, it is possible to have better control of the growth of the inorganic phase using UV curing. It is our ultimate goal to completely separate the curing of inorganic and organic phases to gain complete control over the morphology, and hence optimization of “all” the coating properties. Thus far, it has been found that concomitant UV curing of the inorganic and organic phases using titanium sol-gel precursors afforded nanocomposite coatings which completely block the substrate from UV light while maintaining a transparent to visible light. Also, it has been found that the morphology of the inorganic phase is highly dependent on the concentration and reactivity of the coupling agent. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004, in Chicago, IL.  相似文献   

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