硝酸酯类含能黏合剂绿色合成研究进展

对3种具有发展潜力的硝酸酯类含能黏合剂聚(3-甲基硝酸酯-3-甲基环氧丁烷)(Poly-NIMMO)、聚缩水甘油硝酸酯(PolyGLYN)和硝化端羟基聚丁二烯(NHTPB)的绿色合成工艺和性质进行了简要评述,分析了这些黏合剂的发展前景。并采用以五氧化二氮为硝化剂的绿色合成路线制备得到NHTPB黏合剂,考察了不同官能团对其热稳定性和玻璃化转变温度的影响规律。     

硝酸酯绿色硝化工艺研究进展

简要介绍以五氧化二氮为硝化剂制备硝酸酯的“绿色”硝化反应的类型、工艺及特点。与传统的硝化工艺相比,具有易于控温、无需废酸处理、选择性高、易分离等优点。     

缩水甘油醚硝酸酯合成研究

缩水甘油醚硝酸酯(GN)是合成新型含能黏合剂聚缩水甘油醚硝酸酯(PGN)的单体.介绍了几种合成GN的方法,并对其合成工艺特点进行了简要评述,其中甘油法和N2O5一步硝化法具较好的发展前景.     

二缩水甘油二甘醇胺封端的聚氨酯型深冷胶黏剂的合成、表征及其性能研究

采用一种新方法来提高环氧封端聚氨酯固化速率和室温以上拉伸剪切强度.先以二甘醇胺和环氧氯丙烷为原料,氢氧化钠溶液作为催化剂合成了二缩水甘油二甘醇胺(DGDGA),并用FT-IR,MS对其结构进行了表征.再以自制的DGDGA对异氰酸酯封端的聚氨酯预聚体进行封端,合成了具有高反应活性的缩水甘油胺型聚氨酯(GAPU),用FT-...     

3-氯-1,2-丙二醇及缩水甘油的合成研究

以甘油为原料,在无水乙酸的作用下与HCl反应合成出3-氯-1,2-丙二醇,优化了3-氯-1,2-丙二醇的合成工艺,得到适宜的反应条件为:反应温度90℃,反应时间4 h,催化剂用量5%(w/w),HCl气体流速20 L/h。然后利用制备的3-氯-1,2-丙二醇在二氯甲烷溶剂中与强碱性阴离子交换树脂作用合成了缩水甘油,最佳反应时间为1 h。产物分别通过GC和IR进行了鉴定,3-氯-1,2-丙二醇和缩水甘油的产率分别可达到84.6%和89.6%。     

甘油法合成缩水甘油

以ZnSO4为催化剂,甘油和尿素反应合成碳酸甘油酯,分别以IR和MS对产物进行了结构表征。碳酸甘油酯在磷酸钠催化下脱掉一分子CO2得到缩水甘油。重点对碳酸甘油酯脱CO2得到缩水甘油的反应时间、反应温度、反应压力、催化剂种类及用量等因素进行了考察。并通过响应面分析法得到了适宜的反应条件为：反应时间4 h、反应温度215 ℃、反应压力2 kPa、催化剂用量2.5%（质量分数）。缩水甘油经旋转蒸发提纯,通过IR、HNMR进行了鉴定,GC测定产率可达到83.8%。     

N2O5在硝化反应中的应用进展

五氧化二氮( N2O5)硝化是一种新型的绿色硝化技术.本文综述了五氧化二氮(N2O5)的实验室制法及其在硝化反应中的应用.五氧化二氮( N2O5)主要应用于芳烃硝化,胺的硝解,开环硝化和选择性硝化.     

缩水甘油月桂酸酯的制备

论述了由环氧氯丙烷与月桂酸钠在相转移催化条件下反应制取缩水甘油月桂酸酯的方法。产率在９０％以上。     

7-氯-4,6-二硝基苯并氧化呋咱的合成与表征

以2-硝基-4-氯苯胺为原料,经氧化、环化、硝化,重排得7-氯-4,6-二硝基苯并氧化呋咱;用元素分析、核磁共振、红外光谱表征了其结构;研究了硝化反应温度和5-氯-苯并氧化呋咱与硝酸摩尔比对得率的影响.得出最佳硝化反应条件为:反应温度60℃,5-氯苯并氧化呋咱与硝酸的摩尔比为1∶10,得率为39%.     

新型含氮杂环丁烷阳离子水性聚氨酯的合成

介绍了一种全新的氮杂环丁烷季铵离子作为亲水基团的阳离子水性聚氨酯分散体的合成。采用二异丙醇胺与环氧氯丙烷反应合成缩水甘油基二异丙醇胺,缩水甘油基二异丙醇胺作为扩链剂与聚氨酯预聚体反应而后酸化,将引入聚氨酯结构的缩水甘油胺异构化为氮杂环丁烷季铵离子;然后将含有氮杂环丁烷季铵离子的聚氨酯预聚体分散于水中获得阳离子水性聚氨酯分散体。新型含氮杂环丁烷阳离子水性聚氨酯因其离子性以及氮杂环丁烷的反应活性,在木器封底涂层、纺织整理、蛋白胶交联剂等方面具有潜在的应用前景。     

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.     

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.     

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。