脲醛预聚条件对电泳微胶囊形态的影响

以尿素和甲醛为壁材,油性蓝和二氧化钛纳米粒子分散在四氯乙烯中作为囊芯,通过原位聚合法制备了电泳微胶囊. 研究了脲醛预聚体制备条件对微胶囊形成和产品形态的影响,并通过设计正交实验得到了最优化的制备条件,即脲:甲醛为1:1.75(摩尔比),反应温度75℃,pH值8.5,反应时间1 h. 在最优化条件下制备出的电泳微胶囊内外表面光滑,囊壁透明,分散性好且形态完整.     

脲-甲醛预聚体的制备对玫瑰香精微胶囊化的影响

以脲醛树脂为囊壁的玫瑰香精微胶囊,其囊壁原料脲-甲醛预聚体的制备,采用了碱催化下的加成反应工艺。研究了脲甲醛量比、反应介质的pH值、催化剂、加成反应温度对微胶囊粒径、包埋率及表面结构的影响。优化的加成反应条件为:脲甲醛量比为n(脲)∶n(甲醛)=1∶2.0,以氢氧化钠为碱性催化剂,反应pH=8.0,反应温度70°C,反应时间1h。     

仿生自愈合微胶囊的制备和研究

采用原位聚合法合成了以聚脲甲醛为胶囊壁、环氧树脂为囊芯的微胶囊,并对聚脲甲醛包覆环氧树脂/正丁基缩水甘油醚的微胶囊的制备工艺进行了研究。结果表明,微胶囊制备的最佳工艺条件为：预聚体的pH值在9～10之间,预聚体的反应温度控制在60～65 ℃之间,预聚体反应时间控制在1 h;微胶囊聚合反应的pH值控制在2左右,以十二烷基苯磺酸钠作为表面活性剂,聚合反应温度控制50～60 ℃之间,聚合反应时间控制在2 h。所制备的微胶囊包覆完全,表面致密。     

蜜胺树脂香精微胶囊的制备研究

为改进微胶囊化包覆效果、提高香精微胶囊的性能,通过对蜜胺树脂预聚过程中的三聚氰胺及甲醛摩尔比、pH值、反应温度及反应时间等因素进行研究,得到了用于香精微胶囊壁材的蜜胺树脂预聚体制备的最佳工艺:n(三聚氰胺)∶n(甲醛)=1∶3,反应温度70℃,pH=8~9的条件下反应15 min~25 min。采用该树脂预聚体以原位聚合法制备了香精微胶囊,所得微胶囊在显微镜观察下球形态良好,平均粒径较窄,约为1.5μm。FT-IR结果表明蜜胺树脂对香精的包覆良好;热失重分析说明了微胶囊大幅提高了香精的耐热性能。     

原位聚合法制备分散染料微胶囊

以尿素和甲醛为壁材,分散染料酸性红GP(C.I.266)为囊芯制备了分散染料微胶囊。用SEM和Zeta激光粒度测定仪观察分析微胶囊的粒径分布,讨论了反应条件对微胶囊粒径分布的影响。通过实验,提出了制备该分散染料微胶囊的最佳反应条件为:壁材n(尿素)∶n(甲醛)=2∶3,分散剂阿拉伯树胶质量分数为5%,m(芯材)∶m(壁材)∶m(分散剂)=1∶7 25∶2 5,在pH=3,80℃和搅拌速率为1500r/min的体系中反应2h。     

一步法制备聚脲甲醛包覆反应性乙烯基硅油微胶囊

以聚脲甲醛(PUF)为囊壁,乙烯基硅油为囊芯,采用原位聚合"一步法"成功制备出具有自修复功能且粒径均匀的新型PUF包覆乙烯基硅油微胶囊。研究了分散剂/表面活性剂种类及用量、m(囊芯)∶m(囊壁)比例对微胶囊物理性能的影响,并通过扫描电镜(SEM)、金相显微镜、激光粒度分析仪和红外光谱(FT-IR)法等对微胶囊的形貌、粒径大小等进行了研究。结果表明:选用较高浓度的聚乙烯醇(PVA1799)作为分散剂时,有利于微胶囊的形成;当w(PVA1799)=3.00%(相对于体系总质量而言)、m(囊芯)∶m(囊壁)=2.8∶1.0时,在1500r/min条件下,可制备出平均粒径小于20μm且粒径分布较均匀的理想微胶囊。     

氨基系微胶囊包覆相变材料的研究进展

采用原位聚合法,对影响以脲醛树脂（UF）和三聚氰胺-甲醛树脂（MF）为囊壁的微胶囊相变材料性能的因素,得出以UF为囊壁时,宜采用反应温度为70℃,尿素和甲醛摩尔比为1：2,控制预聚阶段pH为8～9,酸化固化阶段pH为1．5～2;以MF为囊壁时,宜采用反应温度为70℃,三聚氰胺和甲醛摩尔比为1：（2．4-2．5）,控制预聚阶段pH为8-9,酸化固化阶段pH为3;然后选择氯化铵为pH调节剂并采用二次或三次调节,选择合适的乳化分散剂和乳化分散时间,可以获得优异的微胶囊性能。最后展望了氨基系囊壁的发展,并提出了目前面临的困难及急需解决的问题。     

原位聚合法制备聚α-烯烃减阻剂微囊的工艺研究

以聚α-烯烃为囊心,以水和阴离子表面活性剂为分散系统、聚脲甲醛为壁材,采用原位聚合法制备出性能稳定的聚α-烯烃减阻剂微胶囊。利用红外光谱(IR)、扫描电镜(SEM)对微胶囊进行表征,对合成工艺参数进行了优化。结果表明,优化工艺为:尿素与甲醛的摩尔比为1∶2,聚脲甲醛壁材的加入量为10%,表面活性剂量为水量的0.5%,聚α-烯烃减阻剂粉粹至90¹00目,用硫酸调节体系的pH为3,60℃反应2 h。制备的α-烯烃聚脲甲醛微胶囊的表观形貌得到了有效的改善、减阻性能及存储稳定性优异。     

密胺树脂微胶囊制备工艺研究

使用惰性的玻璃微珠作为芯材,用密胺(MF)树脂对其进行包覆,通过平行实验法研究了预聚体配制及包覆过程中不同工艺条件对产物形貌及粒径等方面的影响。结果显示:在制备MF树脂预聚体时,三聚氰胺/甲醛物质的量比为1:2.5,温度80℃,pH值7.5,聚合时间40～60 min时制备出的预聚体较为稳定。在制备微胶囊时,芯囊质量比为1:20,温度65℃,pH值5.5,包覆时间60 min,搅拌速率400 r/min的条件下制备的微胶囊质量最好,微胶囊的形态完整,包覆产物团聚现象和MF树脂结块较少,粒径较小且粒径分布较窄。     

永固红F5R电泳液及其微胶囊的研究

采用十八胺对永固红FSR化学修饰,以Span-80为稳定剂,四氯乙烯为分散介质,使用正交设计方法优化电泳液组成和工艺条件,制备了分散性和稳定性良好的电泳液。使用红外光谱、紫外光谱、激光光散射和光学显微镜技术对永固红FSR电泳液进行了表征。以此电泳液为囊芯,脲甲醛树脂为壁材,制备一种红色电子墨水微胶囊,形貌规则球形,表面光滑,囊壁结构致密,包覆率达81％,囊芯含量为78％。永固红F5R电泳液及其微胶囊具有明显的电场响应行为,可以作为柔板显示器的功能材料。     

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。     

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.