聚四氟乙烯复合材料动态密封性能的研究

采用高速混合、冷压烧结成型法用玻璃纤维、二硫化钼填充改性制备聚四氟乙烯复合材料,探讨了填充料用量对PTFE复合材料拉伸性能和摩擦磨损性能的影响,经测试：当玻璃纤维含量为15％、二硫化钼含量为5％改性PTFE时,其改性复合材料的压缩回弹和耐磨损等综合性能最佳,适用于性能要求较高的动态密封场合。     

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。     

不同填料对聚四氟乙烯导热性能的影响

聚四氟乙烯具有优异的耐腐蚀性，是替代金属材料制备换热器的潜在优质材料。但是，聚四氟乙烯的热导率较低，限制了其在换热器领域中的应用。为了提高聚四氟乙烯的导热性能，采用氧化石墨烯、二硫化钼和鳞片石墨3种填料进行改性，研究了填料种类、填料剂量对PTFE性能的影响。结果表明，3种填料均能提高聚四氟乙烯的热导率，但是，提高程度存在差异，改性程度由高到低分别为鳞片石墨>二硫化钼>氧化石墨烯。当鳞片石墨添加剂的含量6%时，改性聚四氟乙烯的改性效果最佳，热导率提高了59.516%。由于热导率受到填料剂量影响，鳞片石墨和二硫化钼改性聚四氟乙烯的热导率随填料添加量的增加而增加，氧化石墨烯改性聚四氟乙烯的热导率随填料添加量的增加而减小。     

改性聚四氟乙烯活塞环专用料研制

研究了青铜粉、玻璃纤维、二硫化钼复合填充改性聚四氟乙烯(PTFE)的力学性能和耐磨性能,结果表明,偶联剂表面处理的方式有效改善了青铜粉与PTFE的相容性;青铜粉、玻璃纤维和二硫化钼的三元协同改性提高了PTFE的耐磨性和硬度,稍微降低了其拉伸强度和断裂伸长率。最终得到了适用于制作中低压压缩机活塞环的改性PTFE的配方(质量含量,下同):青铜粉18%-20%、玻璃纤维10%-12%、二硫化钼5%、PTFE63%-67%。     

空心微珠在玻纤改性尼龙(PA6)中的应用研究

通过共混改性的方法，利用空心微珠球型的特性，将其填充于玻纤改性的尼龙树脂中；研究了空心微珠对玻纤改性尼龙力学性能的影响。结果表明，在玻纤改性尼龙中加入空心微珠，材料的拉伸强度、冲击强度、硬度及耐热性能都得到提高；当微珠质量分数达到18％时，材料冲击强度达最大值。     

填充改性聚四氟乙烯及其应用

介绍了填充改性聚四氟乙烯的性能、特点,叙述了无机填料和有机高分子材料填充改性聚四氟乙烯及聚合物合金改性的常用方法,以及该材料在汽车、航空及油田领域的应用现状.认为国内对填充改性聚四氟乙烯工艺技术和产品质量控制方面与国外尚有很大差距,应加大研发力度、优化复合工艺、提高装备的自动化水平,借助先进仪器深入研究内部结构与性能的机理关系,提高产品的使用范围及附加值,满足汽车、航空等高端领域的需求.     

二硫化钼高分子复合固体摩擦材料研究进展

简要介绍二硫化钼的组成、分子结构等特征,介绍了二硫化钼在一些领域中的性能研究和应用前景。本文阐述了二硫化钼复合固体材料的性能特点以及二硫化钼对复合材料的摩擦因数和磨损率的影响,重点论述了二硫化钼分别与环氧树脂、聚甲醛、聚四氟乙烯、聚酰亚胺制备复合固体材料的制备过程以及其摩擦效果的研究,揭示了几类复合材料在摩擦过程中表面磨损的机制并对二硫化钼复合固体材料的未来发展趋势做出了展望。     

自润滑复合镀层的摩擦学性能及其强化机理分析

探讨自润滑复合镀层的摩擦学性能及其增强相的摩擦磨损强化机理;分析经具有自润滑性能的石墨、二硫化钼、聚四氟乙烯及碳纳米管等改性的复合镀层的摩擦学行为;并探讨该类复合镀层的摩擦磨损强化机制。     

硅灰石及玻纤复合填充改性聚丙烯的研究

研制成了硅灰石，玻纤复合填充改性聚丙烯树脂，并对其力学性能和结晶行为进行了考查和研究。实验结果表明，硅灰石，玻纤等无机填料在聚丙烯结晶过程中起成核剂作用。     

聚四氟乙烯废料的回收工艺

介绍了聚四氟乙烯（PTFE）废料粉碎后作为填料填充PTFE的回收工艺，研究了PTFE废料粒径及各种填料质量比对PTFE性能的影响，并进行了用石墨和聚苯酯填充PTFE的性能的研究。结果表明：PTFE废料粒径以200目（76μm）为最佳，纯PTFE、铜粉、PTFE废料和二硫化钼的最佳质量比为100：60：30：2，制得的产品拉伸强度19MPa，断裂伸长率300％，满足应用要求；用石墨和聚苯酯填充PTFE时，材料的拉伸强度和断裂伸长率较差，不能满足实际使用要求。     

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.     

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。