复合材料模具用树脂基体的研究

以自制改性咪唑为固化剂,酚醛型EP(环氧树脂)为基体树脂,制备出复合材料模具用中温固化的耐高温EP体系。研究结果表明:当w(改性咪唑)=4%(相对于EP质量而言)时,EP浇铸体的中温(80℃)凝胶时间约为50 min、冲击强度为12.8 kJ/m2、弯曲强度为125 MPa、弯曲模量为3.20 GPa和热变形温度为280℃,具有良好的力学性能和优异的耐高温性能,满足复合材料模具中温固化高温使用的基本要求。     

石墨模具在复合材料成型领域的应用研究

石墨材料具有良好的热传导性,耐高温、耐腐蚀,热稳定性能好,热膨胀系数低,摩擦系数小,这些都便于树脂基复合材料的成型和脱模,并可获得较高精度的制品。本文介绍了石墨材料的特点及在模具加工领域的应用,制造了尺寸相同的石墨模具及金属模具,按照相同的成型工艺分别成型出碳纤维复合材料制品,并进行了比较。结果表明:石墨模具比金属模具更适合成型精度要求比较高的复合材料制品。     

环氧树脂模具助力快速制造技术

在汽车、家电制造业中,占制造工时50%～70%的模具成形零件现状,使业界对模具始终十分关注并不断推进其技术进步,最近环氧树脂模具助力快速制造就是其成果之一。模具制造是制约我国汽车、家电、轻工等行业发展的瓶颈和关键,随着快速成型软硬件设备与快速成型材料的不断发展和完善,快速原型件的强度和精度不断得到提高,快速成型技术已经深入到快速模具制造领域,基于快速成型方法     

高性能复合材料成型用模具材料

本文介绍了复合材料成型用模具材料的发展概况、碳纤维预浸料复合材料模具的特点及其制造工艺。     

环氧树脂型面模具材料的研究及应用

研制的ＪＰ系列模具材料,是以环氧树脂为基材,添加填料,助剂等组成的复合材料,可作为浇铸快速成型模具用的材料,讨论了该材料的组成和性能之间的关系。     

碳纤维复合材料导管叶片模压模具设计

复合材料导管叶片因具有耐腐蚀、高比强度、声阻尼性能优越等传统金属合金制造导管无可比拟的优点,在航空航天和船舶运输领域具有广阔的应用前景。在众多影响复合材料导管叶片成型的因素中,模具设计尤为重要,而目前高生产效率和高精度复合材料导管叶片的模具结构设计面临很多挑战。结合碳纤维复合材料膨胀系数等因素选取超殷钢作为型腔材料,根据装配要求确定了叶片毂头的三个基准,并对模具的型腔进行了整体顶出分块拆卸脱模结构设计,成功组装了模压模具并成型了复合材料导管叶片,证明了设计的可行性与正确性,解决了复合材料叶片模具难以脱模,影响生产效率的问题。     

环氧树脂型面模具材料的研制及应用

研制的JP系列模具材料,是以环氧树脂为基材,添加填料、助剂等组成的复合材料,可作为浇铸快速成型模具用的材料。讨论了该材料的组成和性能之间的关系。     

纤维增强复合材料模具的研制

以不饱和聚酯树脂为基体，无碱玻璃布和短切玻璃毡为增强剂，过氧化甲乙酮为固化剂。环烷酸钴为促进剂，并使用模具用胶衣树脂，研制了不饱和聚酯复合材料模具。论述了该复合材料模具的制作工艺，针对制作过程中经常出现的问题提出了解决方法。该种模具具有成本低、易制造、适用于小批量制品的生产、易制作大型复杂型面的制品等优点。     

氦质谱检漏技术在复合材料成型模具上的应用

介绍了氦质谱检漏技术,简述复合材料成型模具制造过程及其所用的气密性检测方法,对比分析得出采用氦质谱检漏仪对复合材料成型模具进行气密性检测在检测精度、检测成本、检测周期等多方面具有优势,因此将氦质谱检漏技术应用于复合材料成型模具气密性检测具有很大意义。对氦质谱检漏技术在国内外复合材料成型模具上的应用情况进行介绍,在此基础上,对应用于复合材料成型模具气密性检测的氦质谱检漏系统进行设计,并开展检漏实验,总结检漏过程的注意事项。     

复合材料RTM模具的制备

根据树脂传递模塑(RTM)模具对基体树脂的基本要求,选用双酚A环氧乙烯基酯树脂为基体,聚乙酸乙烯酯为低收缩添加剂,玻璃纤维经编织物为增强材料,并加入相应的助剂,制备了复合材料RTM模具。该模具具有成本较低、开发周期短、精度较高等优点,但表面强度和热效率较低。     

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。