高吸水性树脂基水晶花泥的研制

采用盘式法制备淀粉高吸水性树脂,考察了淀粉/单体比、淀粉糊化温度、KPS、处理温度等对合成树脂吸水性能的影响,通过正交分析得出最佳工艺条件:淀粉/AA为1/3,KPS为0.1g,糊化温度90℃,后处理温度110℃,按该配方合成的高吸水性树脂,经过干燥处理后吸水率在500g/g左右.进而合成的水晶花泥吸水率为264g/g,吸盐水率为25g/g,在上染率、保色等方面的性能优于进口的水晶花泥.     

淀粉基高吸水性树脂的制备及吸水性影响因素研究

以玉米淀粉和丙烯酸为原料,N,N-亚甲基双丙烯酰胺为交联剂,过硫酸钾为引发剂,采用水溶液聚合法制备淀粉接枝丙烯酸高吸水性树脂,用红外光谱对其结构进行了表征.适宜的工艺条件为:丙烯酸中和度90%,淀粉用量、交联剂用量及引发剂用量分别为丙烯酸质量的50%、0.01%和0.1%,反应温度50℃、反应时间3h时,制备的高吸水性树脂吸蒸馏水倍率为340g/g,常压10℃放置10d后保水率为47%.     

淀粉接枝丙烯酸高吸水性树脂的合成

以淀粉为主要原料,丙烯酸（AA）为接枝单体,采用水溶液聚合法制备高吸水性树脂。探讨了淀粉、引发剂和交联剂用量,丙烯酸中和度等因素对产物吸水性能的影响,结果表明,在聚合温度为50℃,淀粉、引发剂和交联剂用量分别为丙烯酸用量的10%、0.7%和0.03%的条件下,所制备的高吸水性树脂的吸蒸馏水和生理盐水能力最高可达786 g/g和79 g/g。     

高吸水性树脂基水晶花泥的研制

采用盘式法制备淀粉高吸水性树脂，考察了淀粉／单体比、淀粉糊化温度、KPS、处理温度等对合成树脂吸水性能的影响，通过正交分析得出最佳工艺条件：淀粉／AA为1／3。RPS为0．1g，糊化温度90℃。后处理温度110℃，按该配方合成的高吸水性树脂，经过干燥处理后吸水率在500g／g左右。进而合成的水晶花泥吸水率为264g／g。吸盐水率为25g／g，在上染率、保色等方面的性能优于进口的水晶花泥。     

抗盐性玉米淀粉接枝丙烯酸、丙烯酸羟乙酯高吸水性树脂的研制

以过硫酸钾为引发剂,N,N-二甲基双丙烯酰胺为交联剂,采用化学引发法制备了淀粉接枝丙烯酸、丙烯酸羟乙酯高吸水性共聚物,并研究了丙烯酸与淀粉的配比、丙烯酸羟乙酯与丙烯酸的配比、接枝聚合温度、接枝反应时间、引发剂浓度对共聚物吸液率的影响。制得的高吸水性树脂吸去离子水能力可达560g.g-1以上,吸0.9%溶液达62g.g-1以上。     

水溶液聚合小麦淀粉接枝丙烯酸高吸水性树脂的研究

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。     

淀粉接枝丙烯酸类高吸水性树脂的研究

采用溶液聚合法合成高吸水性树脂.先将淀粉糊化,将丙烯酸用氢氧化钠部分中和后加人到糊化后的淀粉中,用水溶性的过硫酸铵做引发剂,在一定的反应温度和时间下,得到淀粉接枝丙烯酸类高吸水性树脂,其吸水率为853 g/g.本文也探讨了原料配比、反应条件等对吸水率的影响,确定最佳反应条件.     

聚丙烯酸钠∕高岭土复合高吸水性树脂的制备、结构与性能

以丙烯酸和高岭土为原料,用反相悬浮聚合法合成了聚丙烯酸钠/高岭土复合高吸水性树脂.研究了加入高岭土的聚丙烯酸钠复合高吸水性树脂合成中反应温度、中和度、交联剂用量、引发剂用量、高岭土添加量等影响树脂吸水性能的主要因素.结果表明,用反相悬浮聚合法合成的复合高吸水性树脂后处理容易,树脂的吸水率达到512 g/g,吸盐水率达到81 g/g,吸水速度比不加高岭土提高20%,保水能力提高15%,在250 ℃加热30 min仍能保持原吸水率的95%.用IR和TEM研究了复合高吸水性树脂的表面和结构,TEM显示高岭土的加入对树脂颗粒大小和形状有较大的影响,IR初步表明聚丙烯酸与高岭土产生了交联.     

淀粉基高吸水性树脂的合成与性能研究

以马铃薯淀粉和丙烯酸(AA)为原料,过硫酸钾(K2S2O8)为引发剂,三氯化铝(AlCl3)为交联剂,采用以水为溶剂的溶液聚合法制备淀粉基高吸水性树脂(SAP)。确定合理的反应时间,评价树脂的吸水速率、反复吸水性及保水性能。结果表明,在ω(K2S2O8)=0.15%,ω(AlCl3)=0.10%,m(AA)∶m(starch)=6∶1,丙烯酸中和度70%,60℃的条件下,反应80 min制备的树脂吸蒸馏水率为1 235 g/g,吸质量分数为0.9%NaCl溶液率101 g/g,且吸水速率较快,SAP的重复吸水性能和保水性能较好。FTIR分析证实树脂为淀粉与丙烯酸(钠)的接枝共聚物,SAP的XRD衍射峰呈弥散衍射特征,TG和DTA分析说明SAP的热稳定性良好。     

正交设计在合成玉米淀粉接枝丙烯酸共聚物中的应用

以过硫酸铵为引发剂,N,N’-亚甲基双丙烯酰胺为交联剂,在玉米淀粉上接枝丙烯酸制备高吸水性树脂。用正交实验,采用L16(45)正交表,考察了丙烯酸的中和度、淀粉与单体比例、引发剂、交联剂等对高吸水性树脂吸水率的影响。制得的树脂吸纯水率可达1 300 g/g,吸质量分数为0.9%NaCl溶液90倍,有较好的热稳定性。     

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.     

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.     

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。     

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。