高密度聚乙烯/石墨导电复合材料的制备及研究

采用高密度聚乙烯(HDPE)为基体材料,石墨为导电填料,通过物理共混法制备其导电复合材料。对不同石墨添加量的导电复合材料力学性能、热性能和导电性能进行测定,分析了石墨对其复合材料性能的影响。结果表明,不同石墨添加量的复合材料均具有良好的力学性能;石墨填料能够同时改善复合材料的导热性能和热稳定性;石墨能够降低HDPE基复合材料的电阻率,改善材料导电性。     

氢氧化铝对PE-HD／木粉复合材料阻燃性能和力学性能的影响

对Al(OH)3阻燃的高密度聚乙烯／木粉复合材料研究结果表明：随木粉和Al(OH)3添加量的增加，Al(OH)3对复合材料的阻燃效率增加，高木粉添加量的复合材料氧指数达27．1％，Al(OH)3的阻燃效率达0．203。增加木粉含量，复合材料的拉伸强度和弯曲强度明显提高；但Al(OH)3对拉伸强度的影响不大，而明显提高弯曲强度。增加木粉和Al(OH)3的含量，均能明显降低复合材料的冲击强度，破坏复合材料的韧性。     

木粉粒径对木塑复合材料性能的影响

采用不同粒径的木粉填充高密度聚乙烯制备木塑复合材料，研究了木粉粒径对木塑复合材料力学性能和加工流动性的影响。结果表明：木粉粒径对复合材料性能的影响十分明显，较大粒径的木粉有利于复合材料弯曲性能和冲击强度的提高。木粉粒径从100μm增加到850μm，复合材料弯曲强度增加10．4％，弯曲模量增加56．3％，冲击强度增加14．6％。随木粉粒径的增大，拉伸强度呈现先上升后下降的趋势，在200μm时出现最大值。木粉粒径对熔体流动速率（MFR）和密度的影响十分明显，大粒径的木粉使复合材料具有较高的MFR和较低的密度。     

高性能酚醛树脂/石墨双极板导电复合材料的制备

以酚醛树脂与石墨粉料为原料,通过热模压成形得到一种质子交换膜燃料电池双极板材料.研究了酚醛树脂含量、石墨粒径和固化温度对复合材料导电性能与弯曲强度的影响.结果表明随酚醛树脂含量的增加,导电性能降低,强度升高;随石墨粒径的增大,复合材料的导电性能和弯曲强度呈现先增大后减小的趋势;随固化温度的增加,导电性能出现明显波动,而弯曲强度呈先增大后减小的趋势;酚醛树脂质量分数为15%,石墨颗粒粒径为105 μm,固化温度为240℃时,导电复合材料的电导率和弯曲强度可达142 S/cm,61.6 MPa.     

粒径对煤矸石填充聚合物复合材料性能的影响

采用不同粒径的煤矸石粉填充高密度聚乙烯制备复合材料,研究了球磨时间对煤矸石粉体粒径的影响和粒径对煤矸石粉填充聚合物复合材料的力学性能的影响。结果表明：粒径对复合材料的性能影响明显,SEM照片显示超细煤矸石粉与HDPE相容性好;当粒径由100目提高到6000目,填充量为30％时,复合材料的弯曲模量提高了30．77％,弯曲强度提高了37．9％,拉伸强度也提高了20．12％,达到增强增韧的目的。     

mPE-g-MAH对HDPE/木粉复合材料的改性

采用废木粉填充高密度聚乙烯（HDPE）制备木塑复合材料。采用马来酸酐接枝茂金属聚乙烯（mPE—g-MAH）对复合材料进行增容和增韧，并阐述了它的增容和增韧机理。讨论了mPE—g—MAH用量对复合材料的力学性能如拉伸强度、冲击强度、弯曲强度、弯曲模量的影响。结果表明，mPE—g—MAH不仅可明显提高复合材料的强度和韧性，而且也使材料的弯曲模量有了一定的提高。当其质量分数为16％时，复合材料的拉伸强度、冲击强度分别由原来的16．2MPa和4．5kJ／m^2提高到30．5MPa和9．8kJ／m^2。     

碳纳米管增强环氧／石墨复合材料的制备与性能研究

采用粉末冶金法制备了碳纳米管增强环氧／石墨复合材料,并研究了酸洗处理对复合材料弯曲强度、硬度和导电性能的影响。结果表明：与未处理碳纳米管相比,酸处理的碳纳米管增加了环氧／石墨复合材料的弯曲强度和硬度,降低了电阻率。酸处理的碳纳米管增强环氧／石墨复合材料的弯曲强度达到21．9MPa,比未添加碳纳米管时提高了近22％;同时复合材料的硬度达到最大值21．7HS,比未添加碳纳米管时提高了近10％;复合材料的电阻率达到了最小值45036μΩ·cm,比未添加碳纳米管时复合材料的电阻率降低了近17％。     

CB／HDPE复合材料导电性能及导电行为研究

通过熔融共混的方法制备了CB／氯化聚乙烯（CPE）／HDPE复合材料和复合热稳定剂（15％抗氧剂1010,35％抗氧剂DLTP,50％硬脂酸钙）／CB／HDPE复合材料。通过导电性能测试研究TCPE和合热稳定剂对复合材料的导电性能和PTC导电行为的影响。DSC测试研究了复合材料热性能及其对复合材料的导电行为的影响。结果表明,随着CPE用量的增加,复合材料的导电性能提高;复合热稳定剂提高了复合材料的热稳定性,提高热老化后复合材料的PTC强度,可达4个数量级。     

用废木粉增强聚乙烯的研究

本研究采用废木粉为填料增强改性高密度聚乙烯。评价了马来酸酐接枝高密度聚乙烯（MAH-g-HDPE）对聚乙烯基木塑复合材料的增客效果，研究了木粉含量对复合材料力学性能和其它性能的影响，详细阐述了木粉的增强作用机理。研究结果表明：MAH-g-HDPE可显著增进憎水性基质和亲水性木粉之间的界面相互作用，明显改进复合材料的力学性能；在使用适当相客剂的情况下，木粉可明显提高聚乙烯的拉伸强度、弯曲强度和弯曲模量，具有良好的增强效果；当木粉含量为60％时，复合材料的拉伸强度、弯曲强度、弯曲模量分别高达38MPa、54MPa和3500MPa，若与纯基质相比，分别提高了43．4％、176％和283％。这些实验结果表明，木粉对聚乙烯具有明显的增强效果。     

新型导电复合材料性能的研究

以石墨与环氧树脂为原料通过模压成型得到一种新型导电复合材料,考察了石墨粒径、环氧树脂含量及固化时间对导电复合材料性能的影响。试验结果表明,石墨粒径的减小有利于复合材料强度的提高;环氧树脂含量的增加使复合材料的强度明显提高,而导电性能却下降;并且探讨了复合材料性能随不同固化时间而变化的情况．得到了最佳固化时间。     

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.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008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、不饱和聚酯树脂、环氧树脂)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.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料，介绍了2005—2006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生产量以及各国塑料制品的进出口情况。作为对比，介绍了中国塑料的生产情况。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（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序，对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。     

Inorganic/organic nanocomposite coatings: The next step in coating performance

Inorganic/organic hybrid materials have considerable promise and are beginning to become a major area of research for many coating usages, including abrasion and corrosion resistance. Our primary approach is to prepare the inorganic phase in situ within the film formation process of the organic phase. The inorganic phase is introduced via sol-gel chemistry into a thermosetting organic phase. By this method, the size, periodicity, spatial positioning, and density of the inorganic phase can be controlled. An important aspect of the inorganic/organic hybrid materials is the coupling agent. The initial task of the coupling agent is to provide uniform mixing of the oligomeric organic phase with the sol-gel precursors, which are otherwise immiscible. UV-curable inorganic/organic hybrid systems have the advantages of a rapid cure and the ability to be used on heat sensitive substrates such as molded plastics. Also, it is possible to have better control of the growth of the inorganic phase using UV curing. It is our ultimate goal to completely separate the curing of inorganic and organic phases to gain complete control over the morphology, and hence optimization of “all” the coating properties. Thus far, it has been found that concomitant UV curing of the inorganic and organic phases using titanium sol-gel precursors afforded nanocomposite coatings which completely block the substrate from UV light while maintaining a transparent to visible light. Also, it has been found that the morphology of the inorganic phase is highly dependent on the concentration and reactivity of the coupling agent. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004, in Chicago, IL.