丙烯酸-丙烯酰胺共聚物吸水树脂的制备

采用溶液聚合法,以丙烯酸(AA)和丙烯酰胺(AM)为单体,N,N’-亚甲双丙烯酰胺(NMBA)为交联剂,过硫酸铵为引发剂,制备了丙烯酸-丙烯酰胺共聚物吸水树脂,探讨了单体配比(mAA/mAM)、交联剂和引发剂用量对树脂吸水率的影响。结果表明:在65℃时,丙烯酸-丙烯酰胺共聚物吸水树脂的最佳制备条件为:丙烯酸和丙烯酰胺质量比为4:1,交联剂和引发剂用量分别为聚合单体(丙烯酸和丙烯酰胺)总质量的0.02%和0.4%。     

耐盐型丙烯酸-丙烯酰胺接枝共聚高吸水树脂的合成及其性能研究

采用溶液聚合法,以丙烯酸(AA)和丙烯酰胺(AM)为单体,N,N＇-亚甲基双丙烯酰胺(NMBA)为交联剂,过硫酸钾(KPS)为引发剂.合成出丙烯酸-丙烯酰胺接枝共聚高吸水树脂.探讨了单体比[m(丙烯酸):m(丙烯酰胺)]、交联剂和引发荆用量、单体中和度及聚合温度对树脂吸水率的影响.IR光谱表明,丙烯酸和丙烯酰胺发生了接...     

P(AM-AMPS)水凝胶的制备与性能研究

以丙烯酰胺(AM)和2-丙烯酰胺基-2-甲基丙磺酸(AMPS)为原料,N,N’-亚甲基双丙烯酰胺(NMBA)为交联剂,过硫酸铵((NH)S0)和亚硫酸氢钠(NaHSO)为引42283发剂,采用静置水溶液法合成PAM-AMPS水凝胶。讨论了引发剂、交联剂、单体配比、单体浓度、pH值等因素对产物吸水性能的影响。结果表明,合成的水凝胶具有一定的吸水性、吸盐性。()     

微波法制备高吸水性树脂的溶胀性能研究

以2-丙烯酰胺-2-甲基丙磺酸(AMPS)和丙烯酸(AA)为单体,N,N′-亚甲基双丙烯酰胺为交联剂,在不加引发剂的情况下采用微波聚合法合成了丙烯酸-2-丙烯酰胺-2-甲基丙磺酸二元共聚高吸水性树脂。研究了交联剂用量、中和度等因素对产物性能的影响,并对溶胀动力学进行了初步探讨。     

高吸水性树脂PAMA的超声制备与性能研究

超声辐射下,以丙烯酰胺(AM)和2-丙烯酰胺基-2-甲基丙磺酸(AMPS)为原料,N,N-亚甲基双丙烯酰胺(NMBA)为交联剂,合成AM/ AMPS(PAMA)共聚高吸水性树脂.结果表明:单体中AM的质量分数25%、反应体系pH值为2.0、反应温度为45 ℃和交联剂的质量分数为0.01%时,PAMA共聚高吸水性树脂的吸...     

耐盐型聚丙烯酸钠高吸水树脂的合成研究

以过硫酸铵(APS)为引发剂,N,N-亚甲基双丙烯酰胺(MBA)为交联剂,采用反相悬浮乳液聚合法合成了丙烯酸(AA)-丙烯酰胺(AM)-2-丙烯酰胺基辛烷基磺酸钠(NaAMC8S)三元共聚高吸水树脂,研究了引发剂含量、交联剂含量、AA中和度对树脂吸液性能的影响。结果表明:磺酸基单体NaAMC8S的加入显著提高了吸水树脂的盐水吸收能力,当引发剂含量为0.2%,交联剂含量为0.02%,中和度为75%,加入NaAMC8S为0.5%时,共聚树脂吸自来水的量为601mL/g,吸0.9%Nacl水溶液的量为154mL/g。     

PAA-AM交联微球聚合工艺及微球粒径的研究

以丙烯酸(AA)、丙烯酰胺(AM)作为单体、N,N-亚甲基丙烯酰胺(MBA)作为交联剂,利用反向悬浮聚合法制备聚丙烯酸-丙烯酰胺交联微球,研究了分散剂的HLB值及用量、丙烯酸中和度、搅拌速度和交联剂用量对聚合反应及微球粒径的影响。结果表明,分散剂的HLB值为4.5、丙烯酸中和度为80%、搅拌速度为350 r/min、交联剂用量为1%~1.5%的时候,聚合反应过程平稳,所得微球粒径大小适中且分布均匀。     

紫外光引发聚(丙烯酸-丙烯酰胺)/膨润土高吸水性复合材料的制备研究

以N,N-亚甲基双丙烯酰胺(MBAM)为交联剂,Irgacure184为光引发剂,采用紫外光引发聚合的方法制备了聚(丙烯酸-丙烯酰胺)/膨润土高吸水性复合材料。研究了膨润土用量、光引发剂、交联剂、中和度等因素对吸水性能的影响,并用红外吸收光谱(FTIR)、X射线衍射(XRD)和扫描电镜(SEM)的方法表征了复合材料的结构和形态。     

反相乳液法制备聚丙烯酰胺微球及其性能研究

以丙烯酰胺(AM)为主单体,2-丙烯酰胺-2-甲基丙磺酸(AMPS)为功能单体,N,N'-亚甲基双丙烯酰胺(MBA)为交联剂,通过反相乳液聚合法制备了聚丙烯酰胺微球。优化反应较佳合成条件为:油水质量比13∶7,m(AM)∶m(AMPS)=7∶1,交联剂用量2.9%,引发剂用量0.06%,此时乳液平均粒径为278 nm,黏度最小。采用FT-IR、SEM、TG及RS6000流变仪对产物的结构、形貌和性能进行了分析。结果表明,成功合成了目标产物,乳液呈现高分散度的光滑微球,具有较好的黏弹性及耐温耐盐性能。     

丙烯酸-丙烯酰胺共聚物的制备及其重金属离子敏感性研究

以部分中和的丙烯酸、丙烯酰胺为单体,过硫酸钾为引发剂,N,N’-亚甲基双丙烯酰胺为交联剂,采用溶液聚合法直接合成出了一系列不同配方的丙烯酸-丙烯酰胺共聚物(PAAAM)。根据其在氯化钠溶液和在氯化铬、硫酸铜溶液中的溶胀度曲线斜率的显著不同,表明此共聚物对重金属离子较为敏感。结果表明,丙烯酰胺配比为40%,丙烯酸中和度为60%,引发剂用量为0.30%,交联剂用量为0.050%(百分比以丙烯酸为基准)条件下合成的PAAAM的重金属离子敏感性较好。     

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。