尿素反应耦合萃取分离处理乙炔清净工艺废硫酸的研究

乙炔清净工艺产生的废硫酸酸度高且含有较多的有机杂质,有机杂质与硫酸分子能够形成强的相互作用处理困难。采用反应耦合萃取分离方法,利用尿素与硫酸分子形成硫酸脲,消除有机杂质与硫酸分子之间的作用力,同时耦合溶剂萃取可对反应后释放的有机杂质进行分离去除。研究了二氯甲烷/废硫酸体积比、反应时间、尿素/H_2SO_4摩尔比以及H_2SO_4浓度对废硫酸中有机碳去除率的影响。结果表明,二氯甲烷/废硫酸体积比和反应时间影响了有机杂质向萃取相的传质过程,尿素/H_2SO_4摩尔比和H_2SO_4浓度则对有机杂质的释放具有重要影响。较优的工艺条件为:二氯甲烷/废硫酸体积比3∶1,反应时间1.5 h;尿素/H_2SO_4摩尔比1.5∶1,H_2SO_4浓度64.56%。此时的有机碳去除率达到95.21%。     

尿素反应耦合萃取分离处理乙炔清净工艺废硫酸的研究

乙炔清净工艺产生的废硫酸酸度高且含有较多的有机杂质,有机杂质与硫酸分子能够形成强的相互作用处理困难。采用反应耦合萃取分离方法,利用尿素与硫酸分子形成硫酸脲,消除有机杂质与硫酸分子之间的作用力,同时耦合溶剂萃取可对反应后释放的有机杂质进行分离去除。研究了二氯甲烷/废硫酸体积比、反应时间、尿素/H_2SO_4摩尔比以及H_2SO_4浓度对废硫酸中有机碳去除率的影响。结果表明,二氯甲烷/废硫酸体积比和反应时间影响了有机杂质向萃取相的传质过程,尿素/H_2SO_4摩尔比和H_2SO_4浓度则对有机杂质的释放具有重要影响。较优的工艺条件为:二氯甲烷/废硫酸体积比3∶1,反应时间1.5 h;尿素/H_2SO_4摩尔比1.5∶1,H_2SO_4浓度64.56%。此时的有机碳去除率达到95.21%。     

从碲化镉废料中回收碲的研究

以碲化镉废料为原料,采用氧化酸浸工艺回收碲。结果表明,在浸出温度为75℃、硫酸浓度2.5mol·L-1、双氧水加入量为原料质量的0.6倍、液固比为5∶1、浸出时间为120min、搅拌转速为200r·min-1条件下,碲的回收率为98.20%。     

二叔戊基过氧化物的合成工艺研究

以叔戊醇和双氧水在浓硫酸为催化剂的条件下合成二叔戊基过氧化物,研究了温度、反应时间、原料配比、硫酸用量对实验产率的影响,当反应温度25℃,反应时间2 h,双氧水与叔戊醇物质的量比为0.5∶1,浓硫酸与叔戊醇摩物质的量比为1.4∶1时,二叔戊基过氧化物的最佳收率为96%。     

噻螨酮的合成工艺

以赤式-1-对氯苯基-2-氨基丙醇为原料,经酯化反应,二硫化碳环合,双氧水氧化,最后与环己基异氰酸酯缩合得到噻螨酮.酯化中以氯磺酸代替浓硫酸作为反应试剂,提高了产率,缩短了反应时间;二硫化碳环合反应的最佳条件:硫酸酯Ⅱ与二硫化碳的摩尔比为1:3,反应温度55℃;双氧水氧化反应的最佳条件:硫酮Ⅲ、双氧水、甲醇钠的摩尔比为1:3.5:3.5,反应温度30℃.产品含量97.8%,总收率达到77.6%.     

超声波辅助酸浸法回收废旧锂离子电池中的钴

采用湿法技术,通过H2SO4-H2O2体系对废旧锂离子电池正极材料中的钴进行回收。设计正交试验探究了超声时间、双氧水加入量、浸出温度等因素对钴浸出率的影响。结果表明:超声波技术能明显提高钴的浸出率,当超声时间为20 min,硫酸与双氧水体积比为5∶1,浸出温度为80℃时,钴的浸出率可达99%以上。     

硫酸化焙烧-水浸处理废稀土荧光粉工艺

针对当前废稀土荧光粉综合回收利用率低、不当处理造成环境污染严重等问题,采用硫酸化焙烧?水浸法处理废稀土荧光粉,考察了焙烧温度对物料形态的影响及焙烧温度、浓硫酸添加量对稀土氧化物浸出效果的影响,并对该工艺进行了初步环保评估。结果表明,在焙烧温度300℃、时间120 min、浓硫酸与废粉质量比为1.85及浸出温度25℃、时间120 min、液固质量比2:1的条件下,4种稀土氧化物的回收率分别为Y2O3 98.82%, Eu2O3 97.39%, CeO2 96.58%和Tb4O7 98.77%。硫酸化焙烧可使稀土分解为可溶性的硫酸盐和磷酸盐,并保证渣为环保的低放渣。浓硫酸添加量对4种稀土氧化物浸出率影响较大,焙烧温度对CeO2和Tb4O7浸出效果影响显著,在浓硫酸与废粉质量比1.85、浸出温度25℃、时间均为120 min的条件下,CeO2和Tb4O7的浸出率分别由焙烧温度200℃时的40.18%和37.18%提高至300℃时的96.58%和98.77%。稀土荧光粉在300℃下焙烧不会产生SO2和SO3等有害气体,焙烧过程中放出的气体主要为水蒸气和挥发的硫酸,物料失重约为10%。该工艺避免了焙烧过程中产生大量含硫、含氟、强酸性废气及难溶解的焙烧废渣,同时减少了环境污染及部分稀土资源浪费,具有广阔的工业应用前景。     

氧化溴代合成(E)-2-溴甲基-α-甲氧亚胺基苯乙酸甲酯的研究

考察了氢溴酸/双氧水氧化溴代法合成(E)-2-溴甲基-α-甲氧亚胺基苯乙酸甲酯的反应规律。优化反应条件为:反应温度80℃,偶氮二异丁腈(AIBN)作引发剂,n(原料)∶n(H2O2):n(HBr)=1.00∶1.20∶1.05,优化条件下,收率达88.2%。且用溴化钠-硫酸代替氢溴酸,合成(E)-2-溴甲基-α-甲氧亚胺基苯乙酸甲酯的收率为88.2%。     

过氧化新癸酸叔丁酯的合成研究

以叔丁醇和新癸酰氯为原料,合成了过氧化新癸酸叔丁酯引发剂。第一步是以叔丁醇、浓硫酸和双氧水为原料合成叔丁基过氧化氢,考察了叔丁基过氧化氢的合成反应条件。结果表明,在硫酸浓度80%,硫酸与叔丁醇摩尔比1.2∶1,双氧水与叔丁醇摩尔比1.3∶1,反应温度5¹0℃,酯化时间和氧化时间1.5 h和2.0 h条件下,叔丁基过氧化氢的收率可达64.9%。第二步是以新癸酰氯和叔丁基过氧化氢、氢氧化钠为原料,合成过氧化新癸酸叔丁酯引发剂。考察了其合成条件,结果表明,在反应时间1.5 h,新癸酰氯与叔丁基过氧化氢摩尔比为1∶1.2,反应温度20℃条件下,过氧化新癸酸叔丁酯的收率为74.3%。     

草甘膦废水电氧化降解工艺初探

以草甘膦高盐废水专用DSA电极为阳极,采用电化学氧化法对草甘膦生产过程中产生的高盐废母液和废母液蒸发产生的废盐配制的饱和盐水分别进行电解处理,研究了电流密度对降解结果的影响。结果表明:对于草甘膦高盐废母液,当电流密度为2000 mA·cm~(-2)时,COD降解率大于97%,氨氮降解率大于93%;对于废母液蒸发产生的废盐配制的饱和盐水,当电流密度为500 mA·cm~(-2)时,COD降解率大于99%,氨氮降解率大于95%。电化学氧化法对草甘膦高盐废母液和废母液蒸发产生的废盐配制的饱和盐水均具有较好的降解效率。     

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.