离子液体在原子转移自由基聚合中的应用进展

综述了离子液体作为溶剂、单体、引发剂或配体参与原子转移自由基聚合。离子液体具有独特的物理化学性能,可作为溶剂或配体直接参与聚合反应,也可以通过化学修饰合成离子液体型聚合单体或引发剂,利用ATRP技术制备出含有聚合离子液体链段或端基的功能性高分子材料。这种材料可应用于太阳能电池、聚合物电池、光敏元件、吸附剂或传感元件等多个领域,成为高分子材料研究领域的一个重要课题。     

离子液体在原子转移自由基聚合反应中的研究进展

作为一种新型环境友好的"绿色溶剂",室温离子液体已逐步被人们认识和接受。近年来人们将之应用在聚合反应中的研究越来越多,特别是近年发展起来的原子转移自由基活性聚合反应中,使用离子液体不仅可以增大聚合速率和分子量,而且有助于催化剂与聚合物的分离。本文根据近几年的文献资料,阐述了原子转移自由基聚合机理以及离子液体在其中的应用。     

双亲聚合物的合成及其溶液性质的研究进展

综述了双亲聚合物的合成方法,包括经典自由基聚合法、活性离子聚合法、"活性"/可控自由基聚合法及其他方法,着重介绍了近年来才兴起的"活性"/可控自由基聚合法;简要介绍了有关其溶液性质的研究,包括双亲聚合物在选择性溶剂中的胶束化行为,其胶束的增溶作用,并介绍了双亲聚合物在固/液、气/液界面的吸附行为.最后,对双亲聚合物今后的发展方向进行了展望.     

用于二氧化碳吸附的聚离子液体纳米纤维材料及其制备方法

<正>本发明提供了一种用于二氧化碳吸附的聚离子液体纳米纤维材料的制备方法,其特征在于,包括:第一步:将可聚合的含烯基结构的离子液体单体在引发剂和链转移剂的作用下进行可控活性自由基聚合反应制得含烯基聚离子液体;第二步:在室温下,将第一步制得的含烯基聚离子液体搅拌溶解于溶剂中,得到质量分数为5%～30%的电纺原料;第三     

丙烯腈在离子液体中的三元共聚反应

以离子液体1-丁基-3-甲基咪唑硼酸盐([BMIM]BF4)为溶剂,研究了丙烯腈、甲基丙烯酸甲酯和衣康酸在离子液体中的自由基共聚反应。研究结果表明:衣康酸对共聚物的相对分子质量影响很大;离子液体中的共聚产物的化学结构与常规NaSCN水溶液中的聚合产物的结构基本相同,但立构规整性略低。     

吡啶基聚离子液体的制备及热降解行为研究

聚离子液体兼备了离子液体和聚合物的优良性质和结构特点,正成为新的研究热点。本文以4-乙烯基吡啶(VP)和二乙烯基苯(DVB为单体,过二硫酸钾(KPS)为引发剂,通过乳液聚合的方法制备了吡啶基聚离子液体。采用红外光谱分析法、热重分析等表征了聚离子液体的结构以及热稳定性,同时利用Kissinger法对吡啶基聚合离子液体的热降解动力学进行了研究。     

离子液体中催化烯烃齐聚/聚合反应的研究进展

介绍了目前用于烯烃催化齐聚反应和聚合反应方面的离子液体,综述了近些年来离子液体用于液-液两相催化烯烃齐聚反应和聚合反应方面的研究进展.离子液体作为烯烃催化聚合的反应介质,有效地解决了催化剂在溶剂中的溶解性问题;同时指出齐聚反应在将来会有一个快速的发展.     

高效防污涂料离子液体基防污涂层研制成功

中国科学院兰州化学物理研究所近日研制出离子液体基防污涂层。在东海、黄海、南海的挂板实验结果表明,基于离子液体的涂层具有优异的防污效果。研究人员通过表面引发的开环易位聚合,在基底表面接枝上高密度的聚离子液体刷。通过对该功能化材料     

一种在离子液体中制备高性能碳纤维用聚丙烯腈纺丝原液的方法

正一种在离子液体中制备高性能碳纤维用聚内烯腈纺丝原液的方法,将丙烯腈二元共聚体系中的单体或丙烯腈三元共聚体系中的单体依次加入离子液体中,室温溶解,加入引发剂,并通入惰性气体,进行自由基聚合反应。反应结束后用冰浴停止聚合反应,以水凝固聚合产物并反复进行水洗烘干纯化后得到聚丙烯腈粉料。利用二甲基亚砜作为溶剂将上述得到的聚丙烯腈粉料搅拌溶解,得到高性能碳纤维聚内烯腈纺丝原液。该方     

有机玻璃的冷聚合

一、概况甲基丙烯酸甲酯(MMA)的聚合或共聚,一般采用自由基或离子聚合。离子型聚合将MMA分子排列成有规立构结构,工艺目前还处在研究开发阶段。MMA的自由基聚合可用引发剂、辐射、光、热等激发,在生产上普遍采用引发剂引发。聚合方式有本体、悬浮、溶液、乳液等法。MMA的本体法聚合是生产有机玻璃的主要形式。目前,不论使用水浴法或烘房法进行有机玻璃本体聚合生产,均需要在外来加热条件下完成反应,聚合工艺时间长,     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

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.     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

Insect antifeedant properties of anthranoids from the genusVismia

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.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

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.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009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、环氧树脂、不饱和聚酯树脂)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。     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

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.     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。