环保增塑剂二甘醇二苯甲酸酯的合成研究

在对甲苯磺酸催化下、使用环己烷作带水剂,以苯甲酸和二甘醇为原料合成环保增塑剂二甘醇二苯甲酸酯（DEDB）。研究考察了酸醇摩尔比、催化剂用量、带水剂用量和反应时间等因素对产率的影响。确定了最佳工艺条件：n（苯甲酸）∶n（二甘醇）=2.0∶1.1、催化剂用量（以苯甲酸的摩尔数计）3.0%、环己烷12 mL、回流反应时间8 h,目标产品的产率为98.0%。     

二甘醇二苯甲酸酯的催化合成研究

以苯甲酸和二甘醇为原料,二(乙酰丙酮基)钛酸二丁酯为催化剂,通过酯化合成二甘醇二苯甲酸酯(DEDB),探索了增塑剂DEDB的最佳合成工艺条件,并通过FT-IR、核磁共振氢谱(1H-NMR)对合成产物进行了结构分析。研究结果表明:反应原料酸醇摩尔比为2∶1.1、带水剂用量为苯甲酸质量含量的18%、催化剂用量为苯甲酸质量含量的3.0%,反应温度为180℃,反应时间为5h,酯化率达到98.2%。     

玻璃珠载固体超强酸SO_4~(2-)/TiO_2催化合成二甘醇二苯甲酸酯

以玻璃珠为载体,制备了固体超强酸SO42-/TiO2催化剂,用于催化合成二甘醇二苯甲酸酯(DEDB)。通过实验确定了合成DEDB的适宜工艺条件:回流温度为165~170℃,m(甲苯)/m(二甘醇)=0.5,n(苯甲酸)/n(二甘醇)=2.2,m(催化剂)/m(二甘醇)=0.5,反应时间4 h,在该条件下,酯化率可达99.6%。该催化剂经过10次重复使用,活性每次平均下降2.9%。     

二安替比林基一间溴苯基甲烷光度法测定锰的研究

研究了二安替比林基－间溴苯基甲烷（ＤＡｍＢＡ）与锰（Ⅶ）的显色反应条件。在磷酸介质中，Ｍｎ（Ⅱ）存在下，ＤＡｍＢＭ与Ｍｎ（Ⅶ）反应生成橙色产物，λｍａｘ＝４８０ｎｍ。ε＝５．１０×１０５Ｌ·ｍｏｌ－１·ｃｍ－１，锰含量在０．１～１．５μｇ／２５ｍｌ符合比尔定律。该体系灵敏度高，具有一定稳定性。食品中的微量锰（Ⅱ）用过硫酸铰氧化为锰（Ⅶ）后用该法测定，结果满意。     

氧化铝合成增塑剂二苯甲酸二甘醇酯

二苯甲酸二甘醇酯（简称DEDB是一种性能优良的增塑剂，其性能稳定，与PVC、聚醋酸乙烯酯、聚乙烯缩了醛等树脂相容性好，增塑效果佳，而且体积电阻率大，耐油污性好．产品成本低，因而具有良好的实用价值。本文介绍利用直接酯化法合成DED，将苯甲酸、二甘醇以一定比例加入到带有搅拌器、分水器及温度计的烧瓶中，用Al2O3作催化剂，在180－210C进行反应，每小时测定酸值一次，反应完毕后进行减压蒸馏，收集0．67kPa下的产品。经多次实验，得到最佳合成工艺条件是：苯甲酸与二甘醇摩尔配比为1：0．8．催化剂用量为苯甲酸量的8％，反应温…     

二安替比林基─(3─溴)苯墓甲烷与钒(Ⅴ)的显色反应研究

合成并鉴定了一个新的二安替比林类试剂：二安替比林基－（３－溴）苯基甲烷（ＤＡｍＢＭ），研究了它与钒（Ⅴ）的显色条件。在Ｍｎ（Ⅱ）和Ｔｗｅｅｎ－２０存在下，ＤＡｍＢＭ与Ｖ（Ⅴ）在浓Ｈ３ＰＯ４介质中产生橙色产物，λｍａｘ＝４９０ｎｍ。ε＝２．４４×１０６Ｌ．ｍｏｌ－１ｃｍ－１。Ｖ（Ⅴ）量在０．１－１．１μｇ／２５ｍｌ范围内符合比尔定律。用该体系测定中草药中的Ｖ（Ⅴ），结果满意。     

二安替比林苯甲烷光度法测定废水中的铬

本文研究了二安替比林苯甲烷（Ｄｉａｎｔｉ－ｐｙｒｙｌｐｈｅｎｙｌｍｅｔｈａｎｅ，简称ＤＡＰＭ）与铬（Ⅵ）的显色反应。在磷酸介质中，在锰（Ⅱ）和吐温－８０的协同催化下，铬（Ⅵ）可将ＤＡＰＭ氧化成一种橙黄色产物，其最大吸收波长为４８３ｎｍ，表现摩尔吸光系数为７．３８ｘｌ０￣５Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１），铬量在０．１～１．３μｇ／２５ｍｌ范围内符合比耳定律。文中初步探讨了反应的机理。用于废水样品中铬的测定，结果满意。     

二甘醇单丁醚的制备

采用改进的Ｗｉｌｌｉａｍｓｏｎ合成反应方法，以二甘醇、氯丁烷及固碱为原料，一步法合成二甘醇单丁醚。就影响醚化反应收率各因素：原料配比、反应温度、反应时间以及催化剂用量进行了探讨，得到最佳的操作条件分别为：ｎ（二甘醇）：ｎ（氯乙烷）＝５．０￣６．０：１．０、反应温度：７０￣１００℃、反应时间：７￣９ｈ、ｎ（氯乙烷）：ｎ（固碱）＝１．０：１．２，在此条件下收率可达８５．５％。     

混合单元苯羧酸二甘醇酯增塑剂的合成研究

本文以ＣＴＡ氧化残事分离出来的混合单元苯羧酸为原料，和二甘醇进行酯化反应，合成铂混合单元苯酸酸二某醇酯增塑剂，考察了反应温度，催化剂用量，反应时间，醇／酸经对反应的影响，得出最佳工艺条件为：反应温度２１０℃，反应时间７ｈ，催化剂量０．４％，醇／酸为１．５／２（摩尔比）。     

活性炭负载钛酸四丁酯催化合成二甘醇二苯甲酸酯

以活性炭负载钛酸四丁酯[Ti(OBu)4/AC]为催化剂,用于催化合成二甘醇二苯甲酸酯（DEDB）。通过实验确定了合成DEDB的适宜工艺条件：n(BA)∶n(DEG) = 2∶1、催化剂用量为1.25%,带水剂用量为20.0%,反应温度为200℃,反应时间为7h,该反应条件下酯化率可达98.1%。催化重复使用实验表明该催化剂具有良好的稳定性。同时建立了该酯化合成的表观动力学模型,得到反应速率方程为：rA=6.28× 109exp CACB。     

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.     

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.     

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.     

Novel polyurethane coating technology through glycidyl carbamate chemistry

Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.