蒙特卡罗模拟稀土镧/橡胶基复合材料的γ射线屏蔽性能

采用蒙特卡罗模拟方法对5种橡胶基体三元乙丙橡胶(EPDM)、丁基橡胶(IIR)、丁腈橡胶(NBR)、天然橡胶(NR)、丁苯橡胶(SBR)和4种化合物类型的屏蔽功能填料三氧化二镧(La_2O_3)、氯化镧、硝酸镧、碳酸镧对γ射线屏蔽性能的影响进行了研究。结果表明,在5种橡胶基体中,SBR基体在射线穿过时能量沉积最大,EPDM能量沉积最小;在4种镧化合物中,La_2O_3的γ射线屏蔽性能最优。进一步建立以SBR为基体、La_2O_3为屏蔽填料的γ射线屏蔽复合材料模型,模拟计算了不同填料用量和不同厚度复合材料与射线屏蔽性能的关系。结果表明,随着填料质量分数或复合材料厚度的增加,复合材料屏蔽率上升。当填料与基体的质量比为7/3、屏蔽率分别为10%、50%和90%时,复合材料厚度依次为0.61,3.99,13.25 cm。     

纳米碳酸钙的特点与应用

根据纳米碳酸钙的特点及填充补强机理,将白燕华ＣＣ填充于ＮＲ,ＳＢＲ及ＢＲ胶料中,测试其补强填充效果。结果表明,随白燕华ＣＣ用量的增大,ＢＲ和ＳＢＲ胶料的拉伸强度明显上升,而ＮＲ胶料则表现为先缓慢上升,在白燕华ＣＣ用量大于６０份后明显下降;ＳＢＲ和ＢＲ胶料的撕裂强度则不如ＮＲ胶料增长显著。在ＳＢＲ和ＢＲ胶料中随白燕华ＣＣ用量的增大,硫化时间明显缩短。纳米碳酸钙可部分或大部分替代炭黑和白炭黑作补强填料,具有填充量大,补强、增白效果好等特点,适宜在浅色橡胶制品中应用。     

导电环氧树脂基电磁屏蔽材料的制备与性能研究

采用原位聚合法将T-ZnO/Ag粒子填充到环氧树脂基体中,系统研究了填料含量对体系电导率、电磁屏蔽性能和力学性能的影响.研究结果表明:该体系的渗滤阈值介于20％～25％之间,材料的电导率和电磁屏蔽性能均随填料含量的提高而上升,拉伸性能则随填料含量的提高而降低.当填料含量为25％时,体系电导率可达22.4 S/cm,电磁...     

镍包石墨粉聚酰亚胺导电胶的制备与性能表征

先将石墨粉预处理,后采用化学镀法与配制的镀液制备镍包石墨粉,最后加入聚酰亚胺树脂超声制备镍包石墨粉聚酰亚胺导电胶。对合成的镍包石墨粉进行SEM(扫描电镜)表征,探讨超声时间对剪切强度的影响、使用温度和填料含量对体积电阻率的影响、固化温度对电导率的影响以及导电胶在镀铜基板和镀锌基板上接触电阻的比较。研究结果表明:化学镀温度为80℃时,镍包石墨粉包覆效果良好;超声时间15 min、固化温度170℃、填料含量8%制备的导电胶性能较佳,且导电胶使用温度不宜超过200℃;导电胶在镀铜基板上的老化表现优于镀锌基板。制备的镍包石墨粉聚酰亚胺导电胶基本达到了作为导电胶的使用需求,进一步研究应用具有一定的市场前景。     

导电炭黑/杜仲橡胶复合材料导电性能和电磁屏蔽性能的研究

采用机械共混法制备导电炭黑EC-600JD(简称导电炭黑)/杜仲橡胶复合材料,研究导电炭黑用量对复合材料导电性能和电磁屏蔽性能的影响。结果表明:随着导电炭黑用量的增大,复合材料的硬度、定伸应力、拉伸强度和撕裂强度提高,Payne效应增强,电导率和电磁屏蔽效能增大,导电炭黑粒子在橡胶基体中形成导电通路直至形成三维导电网络;当导电炭黑用量为20份时,复合材料的最大电磁屏蔽效能达到33.2 dB,可满足一般工业或者商业用电子设备要求;当导电炭黑用量为25份时,复合材料的电导率达到330 S·m~(-1)。     

一种单组份加成型电磁屏蔽胶的制备与研究

以乙烯基硅油、含氢硅油、气相法白炭黑、镍包石墨粉等原料,制备了单组份加成型电磁屏蔽胶,探讨了催化剂浓度、硅氢比、偶联剂、镍包石墨粉用量对其主要性能的影响。结果表明：单组份催化剂浓度为5 mg/kg,硅氢比为2时,150℃/30 min内基本反应完全,硬度可达49 HA;当镍包石墨粉添加量为65份时,电磁屏蔽胶的综合性能最佳：其中拉伸强度2.0 MPa,断裂伸长率180%,撕裂强度12 N/mm,剪切强度1.6 MPa,体积电阻率0.055Ω·cm;而在耐老化试验中,电磁屏蔽胶的各方面性能也比较良好。     

表面处理剂对白炭黑填充的NBR/NR胶料低温硫化胶性能的影响

研究了表面处理剂三乙醇胺和硅烷偶联剂对白炭黑填充的不同并用比的ＮＢＲ／ＮＲ胶料低温硫化胶性能的影响。结果表明,表面处理剂可改善ＮＢＲ／ＮＲ胶料的耐磨性;胶料撕裂强度的最低值所对应的并用比随表面处理剂类型和硫化温度而变化;并用胶的自粘性随并用比的变化明显存在最低值,当ＮＲ用量大于６０份时,并用胶才重新具有纯ＮＢＲ的自粘性     

碳系复合涂料的制备及其电磁屏蔽性能研究

以水性丙烯酸树脂为基料,鳞片石墨、银粉和炭黑为导电填料,水为溶剂,加入各种分散剂和助剂,制备成水性电磁屏蔽涂料。分析了石墨和银粉的配比、炭黑用量和涂层厚度对涂膜屏蔽性能的影响;结果表明:涂膜的最佳厚度在0.4 mm左右;m(水性丙烯酸树脂)∶m(银粉)∶m(石墨)∶m(炭黑)=5∶3∶2∶0.8,涂膜厚度为(0.4±0.02)mm,8.2~12.4 GHz频率范围内涂膜电磁屏蔽效果可达42 d B,具有较明显的电磁屏蔽性能。     

具有隔离结构的聚苯硫醚/石墨烯纳米片 复合材料的制备及电磁屏蔽性能研究

导电填料石墨烯纳米片（GNPs）通过高速混合包覆于聚苯硫醚（PPS）树脂基体颗粒表面,再通过热压成型制备出具有完善隔离结构的PPS/GNPs复合材料。采用光学显微镜、扫描电子显微镜、电导率测试、电磁屏蔽性能测试对复合材料导电网络形貌、电性能和电磁屏蔽性能进行表征。结果表明,复合材料具有完善的隔离结构导电网络;隔离结构复合材料具备优异的电导率和电磁屏蔽效能（EMI SE）,当GNPs含量为3.0 %（质量分数,下同）时,复合材料的电导率和EMI SE分别为25.6 S/m和41.0 dB。     

BR/NR并用导电橡胶配方设计

采用ＢＲ／ＮＲ并用作为导电橡胶的主体材料，以中超耐磨炭黑作为填充剂进行配方设计。结果证明，当ＢＲ／ＮＲ并用比为７０／３０，中超耐磨炭黑用量为１００份时，胶料的综合物理性能较好，达到导电橡胶的导电性能要求。用此配方生产出的导电制品，使用效果良好，且制品耐磨、耐老化，导电性能稳定。     

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.     

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.     

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。     

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.     

Inorganic/organic nanocomposite coatings: The next step in coating performance

Inorganic/organic hybrid materials have considerable promise and are beginning to become a major area of research for many coating usages, including abrasion and corrosion resistance. Our primary approach is to prepare the inorganic phase in situ within the film formation process of the organic phase. The inorganic phase is introduced via sol-gel chemistry into a thermosetting organic phase. By this method, the size, periodicity, spatial positioning, and density of the inorganic phase can be controlled. An important aspect of the inorganic/organic hybrid materials is the coupling agent. The initial task of the coupling agent is to provide uniform mixing of the oligomeric organic phase with the sol-gel precursors, which are otherwise immiscible. UV-curable inorganic/organic hybrid systems have the advantages of a rapid cure and the ability to be used on heat sensitive substrates such as molded plastics. Also, it is possible to have better control of the growth of the inorganic phase using UV curing. It is our ultimate goal to completely separate the curing of inorganic and organic phases to gain complete control over the morphology, and hence optimization of “all” the coating properties. Thus far, it has been found that concomitant UV curing of the inorganic and organic phases using titanium sol-gel precursors afforded nanocomposite coatings which completely block the substrate from UV light while maintaining a transparent to visible light. Also, it has been found that the morphology of the inorganic phase is highly dependent on the concentration and reactivity of the coupling agent. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004, in Chicago, IL.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Some Large Wood-Boring Beetles in Southeastern USA

Ethanol and α-pinene were tested as attractants for large wood-boring pine beetles in Alabama, Florida, Georgia, North Carolina, and South Carolina in 2002–2004. Multiple-funnel traps baited with (−)-α-pinene (released at about 2 g/d at 25–28°C) were attractive to the following Cerambycidae: Acanthocinus nodosus, A. obsoletus, Arhopalus rusticus nubilus, Asemum striatum, Monochamus titillator, Prionus pocularis, Xylotrechus integer, and X. sagittatus sagittatus. Buprestis lineata (Buprestidae), Alaus myops (Elateridae), and Hylobius pales and Pachylobius picivorus (Curculionidae) were also attracted to traps baited with (−)-α-pinene. In many locations, ethanol synergized attraction of the cerambycids Acanthocinus nodosus, A. obsoletus, Arhopalus r. nubilus, Monochamus titillator, and Xylotrechus s. sagittatus (but not Asemum striatum, Prionus pocularis, or Xylotrechus integer) to traps baited with (−)-α-pinene. Similarly, attraction of Alaus myops, Hylobius pales, and Pachylobius picivorus (but not Buprestis lineata) to traps baited with (−)-α-pinene was synergized by ethanol. These results provide support for the use of traps baited with ethanol and (−)-α-pinene to detect and monitor common large wood-boring beetles from the southeastern region of the USA at ports-of-entry in other countries, as well as forested areas in the USA.