POE／PE反应挤出接枝马来酸酐

研究了辛烯-乙烯共聚物，聚乙烯（POE／PE）的掺混比例、马来酸酐（MAH）单体和过氧化二异丙苯（DCP）用量、第二单体的种类、反应温度、螺杆转速、真空度对接枝产品性能的影响情况以及接枝产品与尼龙共混注塑制得的样品的性能，得到了使该种接枝产品使用性能最佳的配方和工艺条件，即POE／PE为75／25；MAR用量1．3％～1．5％（质量分数），DCP用量：0．04％～0．06％（质量分数），第二单体苯乙烯用量为1．2％～1．5％（质量分数），螺杆转速：40-50r／min，真空度0．01MPa，螺筒温度：140～195℃。     

POE／PE参混反应挤出接枝马来酸酐

研究了辛烯-乙烯共聚物／聚乙烯（POE／PE）的参混比例、马来酸酐（MAH）单体和过氧化二异丙苯（DCP）用量变化、第二单体的种类、反应温度、螺杆转速、真空度对接枝产品性能的影响情况以及接枝产品与尼龙共混注塑打样后的性能，得到了使该种接枝产品使用性能最佳的配方和工艺条件。     

POE／PE参混反应挤出接枝马来酸酐

研究了辛烯一乙烯共聚物／聚乙烯（POE／PE）的参混比例、马来酸酐（MAH）单体和过氧化二异丙苯（DCP）用量变化、第二单体的种类、反应温度、螺杆转速、真空度对接枝产品性能的影响情况以及接枝产品与尼龙共混注塑打样后的性能，得到了使该种接枝产品使用性能最佳的配方和工艺条件。     

POE/PP体系的反应挤出接枝马来酸酐研究

通过研究辛烯-乙烯共聚物/聚丙烯（POE/PP）比例。第二反应单体的选择，马来酸酐（MAH）单体和过氧化二异丙苯（DCP）用量变化以及反应温度，螺杆转速，真空度对接枝产品性能的影响情况，找出了适合于工业生产的最佳配方和工艺条件，即POE/PP为60：40，MAH为1.5%，DCP为0.04%，提纯苯乙烯为1.5%。螺杆转速为45r/min，真空度为-0.10MPa，螺筒各段温度为160，190（反应段），190（除杂段），150（机头）℃。     

POE与马来酸酐的反应挤出接枝

用同向双螺杆挤出机进行热塑性聚烯烃弹性体（POE）的反应，考察了MAH单体、引发剂用量和加工条件对接枝率的影响。结果表明，接枝率随引发剂过氧化二异丙苯（DCP）及MAH用量的增加而出现峰值；螺杆转速对接枝率影响并不明显，而接枝温度则是个关键的因素；较佳的试验配方为POE：MAH：DCP＝100：1：0．15，合适的连接枝温度为180℃。     

POE官能化新方法及其应用

利用熔融接枝法将马来酸酐（MAH）接枝上聚烯烃弹性体（POE），制备了马来酸酐接枝聚烯烃弹性体（POE-g-MAH），探讨了各个因素对POE-g-MAH接枝率和熔体流动速率（MFR）的影响，得出了最佳配方为：50gPOE中加入MAH0．75g，过氧化二异丙苯（DCP）：0．125g；反应温度为180℃，反应时间8min。螺杆转速80r／min^-1在此基础上添加第二单体苯乙烯（St），当St与MAH质量比为0．8，接枝率达到1．02％；将POE与接枝产物POE-g-HMA同时作为弹性体改性尼龙6（PA6），研究发现，弹性体含量一定，PA6／弹性体为80／20，POE，弹性体为20％时，体系的缺口冲击强度较纯尼龙提高接近8倍，而其他力学性能改变不大。     

聚丙烯熔融挤出接枝马来酸酐的研究

研究了通过双螺杆挤出机聚丙烯熔融挤出接枝马来酸酐制马来酸酐接枝聚丙烯（PP—g—MAH）的工艺，包括单体马来酸酐（MAH）、引发剂DCP的用量及熔融反应温度和时间对聚丙烯（PP）熔融接枝MAH的接枝率的影响。结果表明：DCP、MAH的用量对PP—g—MAH接枝率影响比较明显，其最佳配比为DCP0．15份、MAH2份；最佳工艺条件为挤出螺杆转速40r／min，反应温度195-200℃。     

马来酸酐接枝POE改性SAN树脂的制备与性能研究

利用熔融接枝法制备了马来酸酐接枝乙烯-辛烯共聚物（POE-g-MAH），探讨了过氧化异丙苯（DCP）和马来酸酐（MAH）用量对POE—g—MAH接枝率的影响，得出了最佳的DCP和MAH用量分别为0．10份和2．0份。将不同接枝率的POE—g—MAtt与丙烯腈-苯乙烯共聚物（SAN树脂）共混，发现POE—g—MAH的接枝率越高，对POE—g-MAH／SAN体系的缺口冲击强度的提高越显著。     

苯乙烯存在下马来酸酐熔融接枝聚丙烯的研究

分别在哈克流变仪（Haake）和双螺杆挤出机（TSE）中,研究了苯乙烯（St）存在下马来酸酐（MAH）熔融接枝聚丙烯（PP）的过程。讨论了过氧化二异丙苯（DCP）用量、St用量、MAH用量、反应时间、反应温度、螺杆转速以及反应器型式对接枝反应的影响．实验发现：随DCP用量的增加,MAH的接枝率先增加后减小,熔体流动速率（MFR）一直增加;保持MAH用量不变增加St用量时,MAH的接枝率在MAH与St的摩尔比为1：1时达到最大,MFR却一直减小;保持St用量不变增加MAH用量,MAH的接枝率先增加后略有减小,MFR却存在极大值;随反应时间的增加,MAH的接枝率与MFR都先增加后减小;温度过高,MAH的接枝率降低,PP热降解较严重;螺杆转速较低时,MAH的接枝率较低,螺杆转速较高时,PP降解增加;在TSE中的MAH接枝率比Haake中的低,但降解比Haake中的小得多。     

MMA熔融接枝POE的研究

利用熔融接枝法制备了甲基丙烯酸甲酯（MMA）接枝乙烯-辛烯共聚物（POE-g-MMA），探讨了各种因素对POE-g-MMA接枝率和熔体流动速率（MFR）的影响，得出了最佳配方——MMA：1．75g／（50gPOE），DCP：0．25g／（50gPOE），第二单体苯乙烯（St）的加入使接枝率有所提高，St与MMA的量比为1，接枝率达到最高；最佳工艺条件：温度为150℃，反应时间为10min，螺杆转速为80r／min。     

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.