十二烷基三乙氧基硅烷的合成工艺研究

以1-十二碳烯和三乙氧基硅烷为原料,在铂催化下通过硅氢加成反应制得十二烷基三乙氧基硅烷.研究了反应温度、反应时间、催化剂类型、用量和原料的配比对合成产物收率的影响,确立了最佳合成条件:三乙氧基硅烷和1-十二碳烯的量比之为1.05,反应时间为1 h、反应温度为120 ℃,乙烯基双封头-铂-甲苯配合体系作为催化剂且铂催化剂用量为1-十二碳烯量的10×10-6(以铂计).目标产物收率可达83.5%.     

十二烷基甲基二甲氧基硅烷偶联剂的合成研究

以甲基二氯硅烷和1-十二烯为原料,在自制铂催化剂作用下合成中间体十二烷基甲基二氯硅烷,再经无溶剂气-液相反应法醇解得到十二烷基甲基二甲氧基硅烷,对目的产物行了1HNMR、IR 表征。经单因素实验分别确定了硅氢加成和醇解反应的最佳条件：在1-十二烯进料速度5mL/min、n(甲基二氯硅烷)∶n(1-十二烯)=1.1∶1、m(铂催化剂)∶m(甲基二氯硅烷)=1.5×10﹣4∶1、反应温度110℃条件下反应20min,十二烷基甲基二氯硅烷的收率可达92.5%,β-加成产物的选择性为100%;在中间体进料速度1mL/min、甲醇蒸气流量1500 mL/min、反应温度85℃条件下,目的产物十二烷基甲基二甲氧基硅烷经分离提纯后的质量分数为97%,收率可达90.5%。     

十二烷基甲基二甲氧基硅烷偶联剂的合成

以甲基二氯硅烷和1-十二烯为原料,在自制铂催化剂作用下合成中间体十二烷基甲基二氯硅烷,再经无溶剂气-液相反应法醇解得到十二烷基甲基二甲氧基硅烷,对目的产物进行了1HNMR、IR表征。经单因素实验分别确定了硅氢加成和醇解反应的最佳条件:在1-十二烯进料速度5 mL/min、n(甲基二氯硅烷)∶n(1-十二烯)=1.1∶1、m(铂催化剂)∶m(甲基二氯硅烷)=1.5×10-4∶1、反应温度110℃条件下反应20 min,十二烷基甲基二氯硅烷的收率可达92.5%,β-加成产物的选择性为100%;在中间体进料速度1 mL/min、甲醇蒸气流量1 500 mL/min、反应温度85℃条件下,目的产物十二烷基甲基二甲氧基硅烷经分离提纯后的质量分数为97%,收率可达90.5%。     

加成法合成3,3,3-三氟丙基甲基二甲氧基硅烷

以甲基二氯硅烷和甲醇为原料,采用气-液相反应法合成出甲基二甲氧基硅烷;然后,将甲基二甲氧基硅烷与3,3,3-三氟丙烯在铂催化剂作用下进行硅氢加成反应,得到3,3,3-三氟丙基甲基二甲氧基硅烷。考察了原料配比、填料种类等因素对醇解反应的影响以及铂催化剂的种类、用量、反应温度等对加成反应的影响。结果表明,最优合成条件为:在醇解反应中,甲基二氯硅烷与甲醇的量之比为1∶1·8、醇解温度50℃、甲醇滴加速度2mL/min、N2流量80mL/min,在此条件下,甲基二甲氧基硅烷的收率为86%;在加成反应中,采用自制的铂催化剂,当铂催化剂与甲基二甲氧基硅烷的量之比为3·0×10-4∶1、反应温度为120℃时,3,3,3-三氟丙基甲基二甲氧基硅烷的收率达90%。此法可有效提高3,3,3-三氟丙基甲基二甲氧基硅烷的收率。     

相转移催化法合成十二烷基缩水甘油醚

以十二醇和二氯丙醇为原料,用相转移催化剂直接合成了十二烷基缩水甘油醚。考察了催化剂种类、原料摩尔比、反应时间和反应温度对十二烷基缩水甘油醚收率的影响。结果表明,以四丁基溴化铵为催化剂,甲苯为溶剂,n(十二醇)∶n(二氯丙醇)=1∶1.60,反应温度50℃,反应时间4 h,十二烷基缩水甘油醚收率可达73.2%。用IR、1HNMR对产物结构进行了表征,采用测定产品环氧值的方法来计算十二烷基缩水甘油醚的收率。     

氨基长链烷烃共改性聚硅氧烷的合成

以α-蒎烯、甲基二氯硅烷、氯铂酸、甲醇、八甲基环四硅氧烷、N-β-氨乙基-γ-氨丙基甲基二甲氧基硅烷等为原料,通过硅氢加成反应、醇解反应和碱催化共聚反应合成了氨基蒎基改性聚硅氧烷。甲基二氯硅烷与α-蒎烯进行硅氢加成反应较佳的反应条件为反应温度80℃,甲基二氯硅烷与α-蒎烯的量之比1.1∶1,反应时间6h;采用石油醚为溶剂去除醇解反应产生的HCl。     

十烷基三乙氧基硅烷的合成工艺研究

在铂(Pt)催化剂存在下,利用1-十碳烯(C10)和三乙氧基硅烷(TES)进行硅氢加成合成了十烷基三乙氧基硅烷。采用气相色谱-质谱联用仪对合成产物进行了表征。考察了催化剂的种类及用量、反应温度、反应时间和原料配比对产物收率的影响。结果表明:以Pt-四甲基二乙烯基二硅氧烷为催化剂,用量为n(Pt)∶n(TES)=1.2×10-5∶1,原料配比为n(C10)∶n(TES)=0.95∶1,110℃下反应3 h,十烷基三乙氧基硅烷的产率最高,可达98.71%。     

二氧化硅负载铂催化剂的制备及其在硅氢加成反应中的应用

采用乙烯基三乙氧基硅烷对二氧化硅表面羟基进行修饰,再与铂(Pt)配位制得二氧化硅负载卡斯特铂催化剂。以3-氯丙烯与三氯氢硅通过加成反应制备γ-氯丙基三氯硅烷为反应模型,考察了二氧化硅负载铂催化剂的催化性能,研究了催化剂用量、原料配比、反应温度和反应时间对该反应中原料转化率及目标产物选择性的影响,并对回收后的负载铂催化剂进行了活性评价。结果表明,随着负载铂催化剂用量的增加,氯丙烯转化率稍有提高,但γ-氯丙基三氯硅烷选择性降低;与采用等量之比的原料时相比,三氯氢硅用量略微增加时,氯丙烯的转化率由82%提高到90%,γ-氯丙基三氯硅烷选择性没有大幅度变动;随着反应温度的升高,氯丙烯转化率逐渐提高,γ-氯丙基三氯硅烷选择性先略微提高,而后大幅下降。随着反应时间的延长,氯丙烯的转化率先大幅提升,随后缓慢上升并趋于稳定,γ-氯丙基三氯硅烷选择性先提高后保持稳定。该催化剂在三氯氢硅与氯丙烯的硅氢加成反应体系中具有良好的催化活性及选择性,在氯丙烯与三氯氢硅的量之比为1. 1∶1,负载铂催化剂用量为15×10~(-6),反应温度为80℃,反应时间为4 h的条件下,氯丙烯转化率为86. 43%,γ-氯丙基三氯硅烷选择性为75. 88%。此外,经第5次回收后使用,催化活性和选择性无明显下降,在工业领域具有潜在应用价值。     

γ-甲基丙烯酰氧基丙基三甲氧基硅烷的合成研究

以甲基丙烯酸烯丙酯与三氯氢硅为原料,通过硅氢加成反应得到甲基丙烯酰氧基丙基三氯硅烷,再将它与甲醇醇解反应制备甲基丙烯酰氧基丙基三甲氧基硅烷,讨论了影响硅氢加成反应、醇解反应的主要因素,并得出最佳合成工艺条件。     

十六烷基三乙氧基硅烷的合成工艺研究

以1-十六烯和三乙氧基硅烷为原料,通过铂催化合成得到目标化合物,研究了温度、反应时间、催化剂类型、用量和反应原料的配比对合成产率的影响,确立了最佳的合成条件：三乙氧基硅烷和1-十六烯的物质的量比为1.1∶1,反应时间为1h,温度为120℃,铂催化用量为反应物1-十六烯的摩尔量的1×10-（5以Pt计）,产品收率可达82.5%。     

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。