丙烯酸酯聚合物微乳液的合成

加入反应型乳化剂，采用复配乳化剂体系，制得综合性能好的丙烯酸酯聚合物微乳液比较了间歇式微乳液聚合和半连续微乳液聚合对涂膜性能的影响。     

含氟反应性微凝胶在水性自分层涂料中的应用

用自制的核壳型含氟反应性微凝胶与叔丙乳液复配成水性自分层涂料,研究了两种成膜物在涂膜中的形貌、分布以及对涂膜表面动态接触角的影响.结果表明氟碳组分有明显向表面迁移的倾向,在涂膜干燥过程中发生了自分层;含氟微凝胶的引入增强了涂膜的疏水能力.     

反应性微凝胶的制备及其在水性涂料中的应用

采用三缩丙二醇二丙烯酸酯作为交联单体,与不饱和聚酯和/或乙烯系不饱和单体乳液聚合,合成了反应性微凝胶乳液。讨论了聚酯中和度、乳化剂、乳化工艺和聚酯用量对微凝胶性能的影响。举例说明反应性微凝胶在水性金属闪光底色漆、本色面漆和中涂漆中的应用,为解决水性涂料的水敏感性和流挂提供新的技术途径。     

国内期刊荟萃

快速固化的丙烯酸酯微凝胶乳液胡勇辰等. 上海涂料, 2001,(2)：8采用丙烯酸酯类单体合成具有反应性微凝胶的核/壳型胶乳,再通过氨基树脂高温快速固化。讨论了乳化剂组成、核内交联剂的种类含量、壳层单体组成及固化条件等因素对丙烯酸酯微凝胶乳液的稳定性及涂膜性能的影响。试验结果证实,合成具有微凝胶的核、壳型胶乳,有利于快速固化,有利于乳液的稳定性,有利于提高涂膜耐酸、碱性;乳液的钙离子稳定性和冻融稳定性可以通过改变壳层St/BA值来进行调节;本实验体系具有优异的附着力。脂肪族水性聚氨酯涂料的研制许戈文. 涂料工业, …     

丙烯酸酯微凝胶乳液的研究

以核／壳乳液聚合工艺，合成具有反应性微凝胶结构的丙烯酸酯微乳液。讨论了乳化剂和引发剂的选择，丙烯酸酯乳液的组成，合成工艺及固化工艺对涂层性能的影响。     

反应性微凝胶的制备及其在涂料中的应用

介绍了乳液聚合法制备反应性微凝胶,并综述了反应性微凝胶在提高涂料固含量、改善涂料流变性能、涂膜性能以及加快涂层固化方面的应用进展.     

水性双组分涂料用丙烯酸酯乳液的羟值因素

以甲基丙烯酸-β-羟丙酯(HPMA)为羟基单体,采用种子乳液聚合、极性单体分段滴加工艺合成了高羟值(98.8 mgKOH/g)和高固含量(≥45.0%)的丙烯酸酯乳液,配制水性双组分丙烯酸酯聚氨酯涂料(2K-WPU),考查了羟值对聚合稳定性、乳液粒径和涂膜物理化学性能的影响,研究了水性双组分丙烯酸酯聚氨酯涂料合适的-NCO和-OH物质量的比.研究发现:羟值的提高会增加乳液聚合的凝胶率,降低单体的转化率,使乳液聚合稳定性下降,乳液粒径变大,分布变宽;涂膜硬度和交联度随羟值的增大而提高,涂膜光泽和耐介质性能分别在羟值为65.9 mgKOH/g和82.4 mgKOH/g时达到最佳;当n(-NCO)∶n(-OH)为1.5～1.8时,水性双组分丙烯酸酯聚氨酯涂膜的综合性能最佳.傅里叶红外光谱分析表明在涂膜形成过程中-NCO与-OH的固化反应完全需7 d,TGA分析了水性双组分聚氨酯涂膜的耐热性.     

紫外光固化环氧-丙烯酸酯/聚氨酯-丙烯酸酯复合型水性涂料的研制

制备了可反应性的阴离子型聚氨酯-丙烯酸酯，并用其作为乳化剂制成了可紫外光固化的水性环氧-丙烯酸酯／聚氨酯-丙烯酸酯复合型水性涂料。讨论了聚氨酯-丙烯酸酯的乳化机理，及其对环氧-丙烯酸酯水分散体系稳定性及涂膜性能的影响。     

水性丙烯酸酯压敏胶的研究进展

简单介绍了非水乳液聚合、无皂乳液聚合、细乳液聚合以及微乳液聚合方法,总结了交联改性、有机硅改性、增黏树脂改性、纳米粒子改性和反应性乳化剂改性水性丙烯酸酯PSA(压敏胶)的优缺点。最后对水性丙烯酸酯PSA的未来发展方向进行了展望。     

水性丙烯酸酯乳液聚合方法的研究进展

综述了近几年来乳液聚合制备丙烯酸酯乳液的研究进展,主要包括无皂乳液聚合、种子乳液聚合、微乳液聚合、细乳液聚合和辐射乳液聚合等不同方法与特点.另外,对不同丙烯酸酯乳液体系的乳液性能也做了详细阐述.最后对新一代水性丙烯酸乳液产品体系发展前景作了展望.     

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。