POE/SAN的原位增容

通过扭矩测定,傅里叶变换红外光谱、差示扫描量热法分析等方法研究了苯乙烯-丙烯腈共聚物(SAN)与聚烯烃弹性体(POE)大分子间的Friedel-Crafts烷基化反应。结果表明:适量无水AlCl3可以引发SAN与POE发生Friedel-Crafts烷基化反应,生成的POE-g-SAN接枝共聚物起到了原位增容POE/SAN共混物的作用,提高了其力学性能;当m(POE)/m(SAN)为60.0∶40.0,反应温度为180℃,AlCl3用量为0.4 phr时,POE/POE-g-SAN/SAN共混物性能较好;进一步提高AlCl3用量,SAN分子结构中侧链氰基与铝离子络合作用增强,导致SAN分散相聚集,POE/POE-g-SAN/SAN共混物刚性下降。     

原位增容PS/LLDPE共混物的结构与性能

在熔融状态下,利用大分子之间的Friedel-Crafts烷基化反应就地增容聚苯乙烯(PS)/线型低密度聚乙烯(LL-DPE)共混物。考察了AlCl3用量对高PS含量PS/LLDPE(80/20,质量比,下同)共混物的PS接枝百分比和力学性能的影响,同时研究了增容前后共混物的热性能与微观结构。结果表明,在PS/LLDPE共混物中加入0.4份的AlCl3,PS的接枝百分比较高;与简单共混体系相比,共混物力学性能与热稳定性都有所提高,同时PS也有一定程度的降解。     

AlCl3原位增容聚丙烯／聚苯乙烯共混物的研究

采用无水AlCl3作为催化剂引发Friedel—Crafts烷基化反应，用反应共混的方法制备了聚丙烯／聚苯乙烯（PP／PS）合金材料，并用IR、SEM和DSC进行了表征。IR检测到共混物在755cm^-1和3030cm^-1处苯环的吸收峰，证实了PP-g-PS接枝共聚物的存在；SEM的分析表明加入AlCl3后体系的分散相颗粒减小，并且分散也更加均匀；DSC的数据表明加入0．3％AlCl3后体系的玻璃化转变温度（Tg）由99．1℃下降到89．8℃，证明体系形成了相容区。     

LDPE/PS就地相容化研究

在熔融状态下，利用Friedel-crafts烷基化反应就地增容低密度聚乙烯（LDPE）／聚苯乙烯（PS）合金，考察了催化剂品种及其用量、温度、时间等对接枝反应及合金性能的影响。结果显示，无水三氯化铝为一有效催化剂，能实现大分子间的接枝反应，形成LDPE-g-PS，其用量增大时可使体系产生凝胶；升高温度、延长反应时间都不利于接枝百分比的提高；增容后的LDPE／PS合金，其性能得到显著改善。     

PE/PP/PS反应性共混研究

研究了无水AlCl₃在PE/PP/PS共混过程中的反应性作用,考察了无水AlCl₃用量对PE/PP/PS合金力学性能和PP结晶行为的影响。结果表明:在PE/PP/PS共混过程中加入适量的无水AlCl₃,可以起到有效的增容作用,提高了合金的力学性能。     

PS粒径对PP／PS合金性能的影响

研究了不同平均粒径的PS对PP/PS合金流变性能和力学性能的影响.与加入了质量分数为5%的相容剂SBS的PP/PS合金性能进行了对比.结果发现:使用较小粒径的PS原料,更有利于PP/PS合金的增容作用,其综合力学性能更佳.     

反应挤出就地增容HDPE/PS合金

在单螺杆挤出机上,利用路易斯酸实现了大分子间的Friedel—Crafts烷基化反应。考察了不同催化剂体系、催化剂用量及工艺条件对合金性能的影响。结果显示：对于质量比为70．0：30．0的高密度聚乙烯／聚苯乙烯合金体系,通过反应挤出,可以就地生成接枝共聚物;苯乙烯单体的加入有利于接枝物的形成;加入0．8份AlCl3、0．5份苯乙烯单体,控制合适的螺杆温度以及螺杆转速为60r／min时,合金的综合性能较好。     

SBS和AlCl3协同增容LLDPE/PS共混体系

以SBS（苯乙烯／丁二烯／苯乙烯共聚物）和无水AlCl3对LLDPE（线性低密度聚乙烯）／PS（聚苯乙烯）进行增容，考察了不同增容方式及AICIs用量对LLDPE／PS合金性能的影响。结果表明，SBS和AlCl3之间存在协同作用。在LL—DPE／PS（70／30，质量比，下同）共混物中分别加入0．4％（质量分数，下同）AlCl3，10％的SBS，共混物的力学性能较简单共混体系有了明显提高；当二者同时加入后，合金的力学性能优于单一增容体系。在LLDPE／PS／SBS（70130110）体系中加入过量的AlCl3反而会使合金力学性能下降。     

Friedel-Crafts烷基化反应就地增容WPS/OBC合金研究

采用不同种类的回收废旧聚苯乙烯(PS)与乙烯辛烯嵌段共聚物(OBC)进行Friedel-Crafts烷基化反应,考察了催化剂无水AlCl₃用量对废旧PS接枝率和共混物结构、性能的影响。结果表明：由于杂质的存在,回收造粒的发泡PS废旧制件(WEPS)不能与OBC直接进行Friedel-Crafts烷基化反应;而回收造粒的非发泡PS废旧制件(WPS)可以与OBC进行Friedel-Crafts烷基化反应,生成OBC-g-WPS接枝物;当反应温度为140℃,WPS、OBC、无水AlCl₃质量比为50.0/50.0/0.4时,WPS接枝率达到了23.5%,与WPS/OBC简单共混物相比,WPS/OBC/无水AlCl₃共混物拉伸强度和断裂伸长率分别增加了125.4%和2 913.5%;WPS/OBC/无水AlCl₃共混物中OBC的熔点和结晶温度均降低,OBC和WPS两相的相容性得到明显提高;以WPS/OBC/无水AlCl₃(质量比50.0/50.0/0.4)共混物为增容母料增韧WEPS,...     

Friedel-Crafts烷基化反应原位增容SAN/POE研究

在熔融状态下,利用Friedel-Crafts烷基化反应原位增容苯乙烯-丙烯腈共聚物(SAN)/乙烯-辛烯共聚物(POE)共混物,考察了AlCl3对该共混物性能的影响。结果表明,对于SAN/POE(70/30,质量比)共混物,加入0.4%AlCl3时,共混物的拉伸强度提高了31%,断裂伸长率提高了123%;红外光谱分析表明,AlCl3可以引发SAN与POE发生Friedel-Crafts烷基化反应生成SAN-g-POE接枝物;旋转流变分析、热分析以及微观结构分析表明,由于增容体系中有SAN-g-POE接枝物生成,共混体系的表观黏度增加,热稳定性提高,分散均匀性提高。     

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。