碳纤维树脂基复合材料的传感特性研究

通过伏安特性实验,表明碳纤维树脂基复合材料的伏安特性曲线基本过零点,且线性较好,其电流-电压关系符合欧姆定律。通过对碳纤维树脂基复合材料进行拉伸、循环加载等试验,得到其电阻随变形而变化的规律为:在弹性范围内,拉伸加载时电阻值呈可逆地增加;卸载时电阻值呈可逆地减小。结果表明,碳纤维树脂基复合材料具有良好的电阻-变形敏感性,灵敏度高于60,具有满意的线性度和良好的重复性,蠕变很小,稳定性较好。     

船用复合材料轴系的设计研究

本文以典型船用碳纤维增强树脂基复合材料轴系的设计为例,开展了碳纤维复合材料轴系总体设计、碳纤维复合材料传动元件结构设计等研究工作。研究结果表明,在本文具体设计实例中,碳纤维复合材料轴系相比传统钢质轴系可实现减重57%以上。碳纤维轴和联轴器厚度越小补偿反力越小,±45°铺层时轴和联轴器的传扭能力最强;为减小补偿反力,联轴器应选择较小或较大的铺层角;为避免较大挠度,碳纤维轴应选择较小的铺层角度。本文研究结果为复合材料在船用动力系统上的应用奠定了一定的理论基础。     

薄型碳纤维织物预浸料及其复合材料研究

采用国产1k T300级薄型碳纤维织物和中温固化高性能树脂制备预浸料。测试了该预浸料及其复合材料性能,并与国产3k T300级碳纤维织物预浸料及其复合材料性能进行对比。研究结果表明:国产1k T300级薄型碳纤维织物的复合材料性能与国产3k T300级碳纤维织物的复合材料性能相当;该薄型碳纤维织物复合材料的树脂体系是改性增韧环氧树脂,韧性好,适用于轻质夹层结构复合材料,具有较高滚筒剥离强度;同时,该轻质复合材料耐热性好,玻璃化转变温度能达到200℃。     

碳纤维纸增强酚醛树脂基复合材料的制备方法

正本发明提供了一种碳纤维纸增强酚醛树脂基复合材料的制备方法,其将短切碳纤维进行分散、打浆后,通过常规湿法造纸技术制得碳纤维纸,然后将碳纤维纸与酚醛树脂粉末交替铺层后经模压制得碳纤维纸增强酚醛树脂复合材料。该材料中碳纤维的平均长度与纤维浆液打浆时间有关,调节打浆时间可有效控制纤维平均长度;材料中碳纤维的含量与碳纤维纸和树脂叠层厚度的配比有关,碳纤     

基于磁控溅射技术的碳基电磁屏蔽材料

利用磁控溅射技术在碳纤维表面沉积铜膜制备了高效的电磁屏蔽材料,并通过调整磁控溅射时间和碳纤维单向布铺层层数,分析了磁控溅射改性方式和铺层层数对碳纤维织物及其复合材料电磁屏蔽性能的影响。结果表明,磁控溅射碳纤维表面铜膜沉积有利于碳纤维电磁屏蔽性能的改善。经磁控溅射改性处理后,碳纤维电磁屏蔽效能最小提高了37.73%,且电磁屏蔽性能随着磁控溅射时间的延长而增强,但碳纤维电磁屏蔽效能增加率则随磁控溅射时间的增加而逐渐减小。增加碳纤维织物铺层层数有利于碳纤维织物集合体电磁屏蔽性能的改善,但织物层间的不连续性对织物集合体电磁屏蔽性能起消极作用。环氧树脂经碳纤维复合后,电磁屏蔽效能显著增强,增加了约30 dB,但由于环氧树脂对碳纤维的包覆性能,影响了复合材料对电磁波的屏蔽效果,不随碳纤维复合材料中碳纤维织物铺层层数的增加和改性碳纤维导电性能的增加而增强。     

光固化碳纤维布/CEP-ES复合材料粘接修理金属损伤结构

设计了具有紫外光辐照引发自蔓延固化特性的脂环族环氧树脂(CEP)与有机硅树脂(ES)的混合树脂体系(CEPES),并以它们为基体实现了碳纤维增强复合材料的快速光固化。研究了以光固化碳纤维复合材料为补片粘接修理金属损伤结构的影响因素。结果表明,有机硅树脂的引入不仅可以有效提高粘接修理的效果,而且可以改善粘接修理结构的耐湿热性能,当ES的质量比为20%~30%时,粘接修理结构具有最好的承载能力;适当增加复合材料补片的长度和层数可以有效提高粘接修理的效果;双面贴补修理比单面贴补修理具有更好的粘接修理效率。     

三菱推出新型碳纤维复合材料

<正>三菱化学推出一种新型碳纤维复合材料,用该材料制作汽车部件,成本仅为现有材料的一半,这给未来大众市场汽车应用强力、轻型部件带来了光明的前景。通过将碳纤维织物浸入布满长为2~3 cm纤维的树脂中,可得到上述碳纤维复合材料。树脂材料易于成型,加工之前质地柔软,因而可在快速加工(通常在2~5 min)后,通过模压工艺获得汽车所需的零部件。     

三菱化学研发碳纤维新材料 成本可降一半

<正>三菱化学推出一种新型碳纤维复合材料,用该材料制作汽车部件,成本仅为现有材料的一半,这给未来大众市场汽车应用强力、轻型部件带来了光明的前景。据悉,通过将碳纤维织物浸入布满长为2-3厘米纤维的树脂中,可得到上述碳纤维复合材料。树脂材料易于成型,加工之前质地柔软,因而可在快速加工(通常在2-5分钟)后,通过模压工艺获得汽车所需的零     

碳纤维复合材料结构电阻特性研究

为研究碳纤维增强树脂基复合材料(CFRP)的电阻特性,制作了3种不同铺层的试件(单向层合板[0]8、[90]8与交叉层合板[45/-45/90/0]),对试件端部进行了粘接铜箔处理以使试件稳定导电,分别测量试件电阻并对数据进行分析。结果表明,对比电阻值和电导率两个方面都得到了相似的结果,即铺层角度对碳纤维层板结构导电性有较大影响;定量比较3种不同铺层角度试件的电导率发现,[45/-45/90/0]铺层试件的平均电导率约为[0]8铺层试件的0.7倍,约为[90]8铺层试件的60倍。     

专利文摘

可控制热膨胀系数的碳纤维增强树脂基复合材料的制备方法本发明提供了可控制热膨胀系数的碳纤维增强树脂基复合材料的制备方法,该方法利用碳纤维的高强度、高模量、低密度的特点,在纤维的0°方向上具有负的热膨胀系数的重要特性。通过改变复合材料中碳纤维的铺层角度及纤维体积     

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。