固体超强酸树脂催化合成环氧大豆油的工艺研究

以固体超强酸树脂为催化剂合成了环氧大豆油,分别对催化剂用量、反应温度、过氧化氢用量、乙酸用量及反应时间进行单因素和正交试验,并通过极差分析对环氧化过程中显著影响环氧值的因素进行统计分析。结果表明:最佳的合成工艺条件为反应温度70℃、催化剂用量(以大豆油质量为基准,下同)0.45%、过氧化氢用量85%、乙酸用量7.5%、反应时间4.5h,在此工艺条件下环氧大豆油环氧值可达6.55%。     

绿色增塑剂环氧大豆油的合成与表征

用自制的催化剂合成了一种环氧大豆油。通过L16(45)正交试验考察了双氧水用量、催化剂用量、反应时间和反应温度对环氧大豆油环氧值的影响。结果表明:在双氧水用量100份、催化剂用量0.5份(大豆油用量定为100份)、反应温度50℃、反应时间12.5 h的最佳工艺条件下,产品的环氧值为6.58%,碘值为0.83 gI/100g。产品通过红外和核磁共振表征,确定大豆油被环氧化生成环氧大豆油。     

聚氨酯用高羟值大豆油多元醇的合成与表征

本文以大豆油为原料,采用过氧甲酸氧化法制备了高环氧值环氧大豆油(ESO);以氢氧化锂为催化剂,并通过三羟甲基丙烷对其开环合成了高羟值的大豆油多元醇(TESO),研究了反应温度、反应时间对反应进程的影响。用傅里叶红外光谱及1HNMR对其进行表征,结果表明在在190℃下反应4h可以得到高羟基的大豆油多元醇。     

无溶剂自催化合成环氧大豆油的工艺研究

本文对环氧大豆油合成配方与工艺进行了优化。考察了反应物料配比、反应温度、反应时间对产物的环氧值、碘值的影响。通过正交试验,确定环氧大豆油合成的最佳工艺条件:大豆油、甲酸和双氧水的物质的量配比为1∶9∶3,无需添加其他催化剂,搅拌速度为400r/min,反应6h,反应温度55℃左右。在此条件下合成的环氧大豆油的环氧值≥6.8%,碘值≤3.0 g/100 g。产品的外观及色泽均能满足国标要求。     

分子筛(TS-1)催化制备环氧大豆油的研究

以自制的钛硅分子筛TS-1为催化剂,双氧水为环氧化剂制备环氧大豆油。考察了催化剂用量、反应温度、反应时间、双氧水用量等对环氧值的影响,结果表明:在反应温度70℃,投料比m(大豆油):m(H_2O_2):m(TS-1)为1:2.5:0.003,反应时间为4h,产品的环氧值可达到6.50%。     

钨基催化剂体系下甲醇开环环氧大豆油制备多元醇

以环氧大豆油和甲醇为原料,通过开环加成制备植物油基多元醇。在自制的二氯二氧化钨(WO2Cl2)作催化剂、三氟甲磺酸银(Ag OTf)作助催化剂的条件下,考察了催化剂用量、助催化剂用量、反应时间、温度和醇油物质的量比等对环氧大豆油开环转化率的影响,并对产物的环氧值进行了测试。结果表明,当催化剂用量为3%(以甲醇和环氧大豆油总质量为基准,下同),三氟甲磺酸银用量为4%,反应温度为70℃,反应时间为8 h,醇油物质的量比为28∶1时,环氧大豆油的开环转化率较高,为89.13%。对开环产物进行了FTIR、1HNMR、TG以及流变性分析。通过热重分析得出,多元醇的分解温度(334℃)比环氧大豆油的分解温度(305℃)高。流变性分析得出,随着温度的升高,环氧大豆油和多元醇的黏度逐渐下降。在温度较低时,大豆油多元醇的黏度明显低于环氧大豆油的黏度。     

环氧大豆油脱色工艺研究

研究在碱性介质下过氧化氢对环氧大豆油的脱色工艺,考察了过氧化氢和氢氧化钠用量、反应温度、反应时间等因素对脱色工艺的影响.得到最优脱色工艺条件为:物料配比(重量比)为ESO:NaOH(100%):H2O2(100%)=100:1.0～1.2:1 6～2 0,反应时间为50-60min,反应温度为75℃～80℃.在此条件下可将环氧大豆油的色泽由>250号降低至<150号,明显降低环氧大豆油的色泽,提高质量水平.     

多双键丙烯酸化环氧大豆油的制备与表征

本文以大豆油(SBO)为原料,采用过氧甲酸氧化法制备了不同环氧值的环氧大豆油(ESO);分别用丙烯酸和甲基丙烯酸对ESO进行开环反应制备丙烯酸化环氧大豆油。分别测定了大豆油及环氧大豆油的环氧值和碘值以及环氧大豆油丙烯酸化反应前后的酸值,并用红外光谱对产物进行表征。结果表明:通过控制大豆油、甲酸和双氧水的比例可以制备出不同环氧值的环氧大豆油;丙烯酸比甲基丙烯酸更容易开环环氧大豆油。     

以树脂为催化剂制备环氧大豆油的研究

本文研究了在酸性离子交换树脂催化下大豆油的环氧化,研究了树脂用量及交联度、反应时间、反应温度等因素对产品环氧值的影响,并得出了环氧化、碱洗、水洗、减压蒸馏等过程的优惠工艺条件.     

植物油基多元醇的合成研究

该文以环氧大豆油(ESBO)和甲醇为原料,在SO42-/ZrO2固体酸催化作用下,通过开环加成反应制备了植物油多元醇(Polyol)。借助红外、核磁共振、热分析等技术对产物结构和性质进行了分析,考察了原料配比、反应温度、反应时间和催化剂用量对ESBO转化率和多元醇合成的影响。结果表明:在反应原料配比n(甲醇)∶n(ESBO)=50∶1,反应温度373 K,反应时间2 h条件下,环氧大豆油转化率为96.8%,羟基值为198.3 mg KOH/g。     

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.