改性片麻岩催化合成羟基酯的研究

以乳酸与醇的酯化反应、酒石酸与醇的酯化反应及羧酸与环氧氯丙烷得开环酯化反应为模型反应 ,研究了改性片麻岩作为催化剂对上述反应的催化性能。在n (羧酸 )∶n(醇 ) =1 0∶5 2的条件下发生酯化反应 ,羧酸转化率不低于 90 % ,而且基本不发生羟基酸分子间的酯化反应。改性片麻岩对羧酸的酯化反应具有催化作用 ,而且副反应少 ,易于分离 ,无环境污染     

磷酸淀粉单酯的制备与应用

一、制备方法淀粉易与磷酸盐发生酯化反应,生成酯的衍生物,有磷酸淀粉一酯(单酯)、二酯和三酯。磷酸淀粉单酯是淀粉的一个羟基与正磷酸盐酯化而得的酯。常用于单酯型的试剂有磷酸、磷酸二氢钠和磷酸氢二钠等。反应式如下:     

多壁碳纳米管接枝超支化聚(胺-酯)

采用混酸氧化,使碳纳米管表面产生羧基,再分别以接出法(grafting from)的方式在碳纳米管表面"长出"超支化大分子;以接入法(grafting to)的方式将由"一步法"合成的超支化聚(胺-酯)通过酯化反应接枝到碳纳米管表面。通过SEM、FTIR、TGA-DSC以及XRD等表征手段并结合酸碱滴定法测定修饰后碳纳米管表面的羟基密度,对功能化修饰的碳纳米管进行分析。结果表明,分别以"grafting from"和"grafting to"方式接枝超支化聚(胺-酯)后,碳纳米管的羟基密度分别为24.74 mmol/g和20.04 mmol/g,修饰后的碳纳米管分散性能明显提高,同时末端丰富的官能团为碳纳米管的进一步功能化修饰创造了条件。     

最新专利

正一种多羟基柔性聚酯纤维的制备方法(申请号CN201410037982申请日2014.01.26申请人东华大学)该发明涉及一种多羟基柔性聚酯纤维的制备方法。将二元醇、多羟基与聚乙二醇大分子按照一定的摩尔比混合,利用分阶段酯化,第一酯化阶段酸微过量,保证多元醇中参加酯化反应能力较低的部分充分反应,接入到聚酯分子链中。在第二酯化阶段补充二元醇对共聚酯的端羧基进行调     

松香与甲基丙烯酸-β-羟乙酯的酯化反应和加成反应研究

研究了松香与甲基丙烯酸-β-羟乙酯(HEMA)的酯化反应和加成反应,探讨了阻聚剂、催化剂种类和用量、反应温度和原料配比等对酯化反应和加成反应的影响,并采用红外光谱(FT-IR)法和热重分析(TGA)法分别表征了产物的分子结构和酯化物的热稳定性。结果表明:松香分子中的羧基和双键分别与HEMA分子中的羟基和双键发生了酯化反应和加成反应;氧化锌是酯化反应较好的催化剂,当w(氧化锌)=1.0%(相对于松香而言)、反应温度为220℃时,有利于酯化反应的进行;HEMA用量越多,越有利于加成反应的进行;FT-IR表明已成功制取了松香与HEMA的反应产物,TGA表明该产物的热稳定性明显提高。     

膦酸酯修饰的多壁碳纳米管的制备与表征

为提高多壁碳纳米管(MWCNTs)的表面活性,故对其表面进行有机修饰。以苯酚为原料,分别通过磷酸化和phospha-Fries重排反应,合成了2-羟基-苯膦酸二乙酯。膦酸酯上的羟基与酰氯化的多壁碳纳米管发生反应,得到了膦酸酯修饰的多壁碳纳米管。核磁共振波谱和红外光谱表征分析了膦酸酯及膦酸酯修饰的碳纳米管的组成结构,并且对比了修饰与未修饰的碳纳米管的分散性。结果表明,膦酸酯对碳纳米管的表面修饰有助于提高其在四氢呋喃中的分散性。     

对羟基苯甲酸乙酯的合成

对羟基苯甲酸乙酯又叫尼泊金乙酯,它的分子式是C_9H_(10)O_3,分子量为166.173 9,对羟基苯甲酸乙酯是对羟基苯甲酸与乙醇发生反应,进行酯化反应,然后再进行精致提炼。对羟基苯甲酸乙酯合成原料主要有对羟基苯甲酸,以及乙醇,使用的催化剂主要是氨基磺酸,主要研究了对羟基苯甲酸乙酯的合成,以及各种影响因素。     

端羟基聚环氧氯丙烷酯化反应研究

通过端羟基聚环氧氯丙烷(PECH)的酯化,合成了端酯基PECH,用FT-IR和NMR进行了结构表征。优化了酯化反应工艺,结果表明:以乙酸酐为酯化剂,酯化剂与羟基物质的量比为1.6;N-甲基咪唑为催化剂,催化剂质量分数为3.6%;1,2-二氯乙烷为溶剂,反应温度为80℃,反应时间为0.5h,则羟基转化率为100%,收率>94.3%。     

PBS酯化反应及副反应影响因素的研究(二)

研究了丁二酸二甲酯和1,4-丁二醇酯交换反应过程中,酯化率与四氢呋喃生成率随反应时间的变化,通过分析反应温度、催化剂以及酸的影响,探讨了端丁羟基脱除反应对生成四氢呋喃副反应的贡献.结果表明:PBS直接酯化反应过程中,端丁羟基脱除反应对生成THF的贡献远小于1,4-丁二醇的环化反应,Ti(OBu)4的加入可以降低端丁羟基脱除反应,丁二酸的存在以及反应温度的提高对端丁羟基脱除反应具有一定的促进作用.     

马来酸酐改性油酸基聚酯多元醇的合成

以油酸为原料,经羟基化、酸酐改性、酯化合成油酸基聚酯多元醇,考察了摩尔比、常压反应温度时间、减压反应温度时间、催化剂用量等因素对酯化反应的影响,研究了不同组合酯化试剂对多元醇性能的影响。采用红外光谱(FT-IR)、高效凝胶色谱(GPC)、热重(TGA)对多元醇的结构、相对分子质量、热稳定性进行了表征。结果表明,最佳酯化条件为醇酸比n(二甘醇)∶n(羟基油酸)=1.1∶1,催化剂Zn O量为0.8%,常压、210℃下反应90min,再在180℃下减压反应120min。     

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.     

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。     

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.     

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.     

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.