聚丙烯复合材料的力学性能和耐刮擦性能研究

以聚丙烯(PP)、滑石粉(Talc)、SEBS和绒毛粉为原料,采用熔融共混方法制备了PP复合材料。分别研究了SEBS及绒毛粉对PP复合材料力学性能和耐刮擦性能的影响。利用交叉刮擦法对耐刮擦性能进行了表征。结果表明:在一定范围内SEBS具有增韧作用,但随着SEBS含量的增加,PP的拉伸强度、弯曲强度以及耐刮擦性能逐渐降低。随着SEBS含量的增加,ΔL逐渐增加;少量添加绒毛粉对复合材料除冲击强度以外的性能影响较小,添加少量绒毛粉便能显著提高材料的耐刮擦性能。随着绒毛粉含量的增加,ΔL值相应地降低。     

磷酸酯偶联剂(FX-1)对PP/POE/Talc复合材料性能的影响

通过熔融共混法制备了PP/POE/Talc复合材料,研究了偶联剂磷酸酯(FX-1)不同含量对滑石粉表面性能的影响,得出了偶联剂磷酸酯(FX-1)的最佳质量分数为1%;同时,考察了超细滑石粉经偶联剂磷酸酯(FX-1)改性前后与基体PP界面的粘接情况对PP/POE/Talc复合材料力学性能的影响。     

聚丙烯/有机蒙脱土/滑石粉纳米复合材料的制备与性能研究

采用双螺杆挤出机直接熔混的工艺,以聚丙烯(PP)为基体树脂,以滑石粉(Talc)和经有机改性的蒙脱土(OMMT)为填料,以马来酸酐接枝聚丙烯(MAH-g-PP)为相容剂,分别制备了PP/OMMT和PP/OMMT/Talc纳米复合材料。结果表明,所得PP/OMMT复合材料为蒙脱土剥离或部分剥离的纳米复合材料;PP/OMMT/Talc复合材料的性能优于两种填料分别填充改性的PP材料,且分散及改性效果基本没有互相影响;与传统PP/Talc复合材料相比,制备的PP/OMMT/Talc纳米复合材料在各性能相近或更好的前提下,密度可以减少7%～10%。     

PP复合材料耐刮擦性能的研究

通过多指刮擦试验机对聚丙烯(PP)及其复合材料进行了系统的刮擦实验测试,采用光学显微镜观察了材料的刮擦损伤形貌,以研究PP及其复合材料的耐刮擦性能及损伤机理;通过差示扫描量热仪(DSC)测试了材料的结晶度,研究了耐刮擦助剂和磷酸盐成核剂对材料力学性能、结晶性能和耐刮擦性能的影响,以探讨材料力学性能、结晶性能与耐刮擦性能之间的关系。     

高强度PMMA基复合材料的制备及在室内设计中的应用

采用扩链剂、相容剂和云母粉作为增刚助剂,制备聚碳酸酯/聚甲基丙烯酸甲酯(PC/PMMA)复合材料,探究不同增刚助剂含量对复合材料拉伸强度、耐刮擦性能、硬度和光泽度的影响。结果表明:随着扩链剂含量的提高,复合材料耐刮擦性能、拉伸强度、硬度和光泽度都得到改善;苯乙烯/马来酸酐共聚物(SMA)能够改善复合材料表面性能,但对复合材料光泽度有略微影响,随着其含量增加,复合材料拉伸性能呈现先升高后降低的趋势;随着云母的加入,复合材料表面硬度进一步提高,光泽度和耐刮擦性能略微下降,拉伸强度也呈先提高后降低趋势;最佳复合材料配方为m(PC)∶m(PMMA)∶m(扩链剂)∶m(SMA)∶m(云母粉)=20∶80∶0.4∶3∶10,此时复合材料表面邵D硬度达到85,刮痕处ΔL值达到1.5,光泽度为70°,拉伸强度达到58.9 MPa,具有高强度、高光泽和耐刮擦特点。     

硅酮耐刮擦剂对车用PP复合材料性能的影响

研究了三种不同牌号的硅酮耐刮擦母粒对聚丙烯(PP)复合材料的物理力学性能和耐刮擦性能的影响,采用3D激光扫描共聚焦显微镜(CSLM)对划痕表面形貌、截面形貌进行观察和3D模拟。结果表明,硅酮母粒降低了材料的强度、刚性和表面硬度,而且洛氏硬度和拉伸强度有一致的变化关系。划痕横截面积与ΔL值有一定的对应关系,都可以作为评价材料耐刮擦性的指标。通过CSLM的3D模拟图可以定性评价材料的耐刮擦性。     

尼龙6对聚丙烯复合材料耐刮擦性能的影响

采用熔融共混方法,制备了聚丙烯(PP)/聚四氟乙烯(PTFE)/尼龙6(PA6)复合材料,研究了PA6对PP复合材料力学性能和耐刮擦性能的影响.采用光学显微镜(OM)等手段对聚丙烯(PP)复合材料的耐刮擦行为进行了研究.结果表明,均聚PP与共聚PP相比,显示出了优异的耐刮擦性;PA6增加了PP复合材料的模量和强度,从而改善了材料的耐刮擦性能.     

PP/Talc/MA-SEBS复合材料的力学性能研究

选用MA-SEBS为增容剂,制备了PP/滑石粉(Talc)/MA-SEBS复合材料,研究了Talc和MA-SEBS的含量对复合材料力学性能的影响.结果表明,单纯加入一定量Talc可以明显提高PP冲击强度,再加入MA-SEBs后,复合材料的冲击强度进一步增加.MA-SEBS除了作为相容剂.也充当增韧剂.刚性粒子Talc使...     

低散发耐刮擦汽车内饰用聚丙烯复合材料的研制

采用熔融挤出法制备了一种低散发耐刮擦汽车内饰用聚丙烯(PP)复合材料,研究了不同用量的耐刮擦剂和气味吸附剂对PP复合材料耐刮擦性能和气味散发特性的影响.结果表明,当耐刮擦剂和气味吸附剂的质量分数分别为1.5％和1％时,PP复合材料具有较优异的耐刮擦性能和低气味散发特性,且其力学性能不受影响.该复合材料已成功应用于各种汽车内饰件.     

PP/M-HOS/POE三元复合材料的界面改性与力学性能

采用马来酸酐接枝聚丙烯(PP-g-MAH)及马来酸酐接枝乙烯-1-辛烯共聚物(POE-g-MAH)为界面相容剂，利用熔融共混法制备PP／镁盐晶须(M—HOS)／POE三元复合材料，研究了PP-g-MAH及POE-g-MAH的用量及配比、M-HOS和POE的用量对三元复合材料力学性能的影响。结果表明：当PP／M-HOS／POE的质量比为100／10／20时，PP-g-MAH的最佳用量为3份；利用PP-g-MAH及POE-g-MAH作为复合相容剂可同时改善M-HOS与PP和POE的界面相容性，促进POE、M-HOS对PP的增韧补强作用，使三元复合材料的力学性能得到了明显的改善。     

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.     

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.     

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.     

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.     

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。     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。