无机材料填充改性PTFE复合材料研究进展

综述了聚四氟乙烯（PTFE）无机材料填充改性中纤维填充改性，颗粒填充改性以及复合填充改性三大类的改性研究进展。介绍了不同无机填料对于PTFE复合材料的力学性能以及摩擦学性能的影响，包括摩擦因数、拉伸强度以及材料硬度等，发现铜（Cu）粉、二硫化钼（MoS2）以及玻璃纤维（GF）等无机填料成本较低且对PTFE的力学性能以及摩擦学性能改善较为明显，更能满足实际工程应用。最后，分析了国内外近年来研究中所存在的问题，并提出了解决方向。     

基于聚甲醛及其复合材料的摩擦学研究进展

介绍了聚甲醛（POM）的基本物理化学性能,综述了聚四氟乙烯（PTFE）共混、无机粒子填充、添加纳米粒子、纤维增强、绿色填料及多元复合对POM复合材料摩擦磨损性能研究进展,指出今后应加强对多因素协同作用下POM复合材料的磨损机理和绿色POM复合材料摩擦学方面的研究。     

海泡石/空心微珠/环氧树脂复合涂层在镁合金表面的隔热性能研究

通过SEM、TGA、隔热性能测试等方法研究了加入不同量无机填料的环氧树脂复合涂层的结构和性能。无机纤维海泡石的加入提高了环氧树脂的耐热性能,同时在空心微珠之间起到填充和阻热的作用。当纤维状无机填料海泡石与球状无机填料空心玻璃微珠的加入量分别达到15%时,厚度约3.0mm的涂层在经受500℃高温2 min后,镁合金基体背面温度大约为300℃。随着无机填料加入量的进一步增加,隔热效果反而变差。在实验结果的基础上,建立了两种填料高分子复合材料的传热模型,分析了两种填料在涂层隔热过程中的作用机理。     

聚甲醛/海泡石纤维复合材料的制备与性能研究

为制备性能优良的聚甲醛（POM）基复合材料,以海泡石纤维（Sep）填充POM制备POM/Sep复合材料。研究硅烷偶联剂KH550表面改性填料对复合材料力学和摩擦学性能的影响。复合材料的力学性能以及摩擦学性能随着Sep含量的增加而改善,当有机改性海泡石纤维（O-Sep）含量为5.0 %（质量分数,下同）时,POM/O-Sep复合材料的拉伸强度、弯曲强度、弯曲模量和冲击性能分别达到最优值68.43 MPa、89.81 MPa、3600.61 MPa和285.5 kJ/m2,与纯POM相比提高了28.6 %、51.9 %、79.1 %和8.8 %;且POM/5.0 %O-Sep复合材料的摩擦因数和磨损量分别达到0.072和3.6 mg,与纯POM相比降低了65.9 %和 35.7 %。     

填料填充改性聚甲醛复合材料研究进展

综述了近年来不同无机纤维、无机粒子、有机填料与无机填料混合物及金属及其氧化物对聚甲醛(POM)复合材料改性的研究进展。介绍了填料在POM复合材料改性中的作用,对填料填充改性POM复合材料的发展趋势进行了展望。     

聚醚醚酮复合材料摩擦学性能研究现状

介绍聚醚醚酮(PEEK)的基本物理化学性能,评述粒子填充、纤维增强、有机-无机共混和等离子处理PEEK复合材料的摩擦磨损性能研究进展,指出今后应加强对多因素协同作用下PEEK复合材料磨损机理、开展PEEK复合材料微观摩擦学及生物摩擦学方面的研究。     

环氧树脂基阻尼复合材料研究进展

简要阐述了高聚物阻尼材料的阻尼机理,综述了环氧树脂胶液的阻尼性能及其影响因素、纤维增强环氧树脂阻尼复合材料以及无机填料/环氧树脂阻尼复合材料的研究状况,指出了环氧树脂基阻尼材料的发展方向及前景。     

聚四氟乙烯复合材料摩擦学性能研究

综述了PTFE复合材料摩擦学性能的国内外研究进展,系统阐述了不同填料对PTFE复合材料摩擦学性能的影响,指出多种填料混合填充可提高PTFE复合材料的承载能力和耐磨损性能,降低其摩擦系数.     

一种导电碳纤维复合材料及其制备方法

正本发明涉及一种导电碳纤维复合材料及其制备方法,该复合材料包括碳纤维、环氧树脂基体材料和均匀分散于该环氧树脂基体材料中的无机纳米填料;复合纳米无机填料由石墨烯和铜纳米线组成。本发明利用石墨烯和铜纳米线有效提高了碳纤维复合材料的导电性能,使复合材料的电导率由210 S/cm提高到6 500 S/cm。专利申请号:201310485848.3公开号:CN103525013A申请人:嘉兴市隆鑫碳纤维制品有限公司     

有机聚合物／无机化合物纳米复合阻燃材料研究进展

综述了有机聚合物／无机化合物纳米复合阻燃材料的研究和应用现状。阐述的纳米复合阻燃材料包括有机聚合物／层状硅酸盐纳米复合材料、有机聚合物／碳纳米管纳米复合材料、有机聚合物／二氧化硅纳米复合材料、有机聚合物／石墨纳米复合材料等。与传统无机阻燃剂填充阻燃材料相比,这类新型纳米复合阻燃材料的填料与基体的亲合性、基体的物理力学性能和阻燃性能等均得到改善。     

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.