抗静电半硬质聚氨酯泡沫塑料的制备与性能研究

以导电炭黑和十六烷基三甲基溴化铵(CTAB)为抗静电剂通过特殊的工艺制备了抗静电半硬质聚氨酯泡沫塑料(SRPUF).当导电炭黑用量大于3份,或采用1.5份以上导电炭黑与2.5份CTAB相结合,可以制得体积电阻率在108～109Ω·cm范围的具有开孔结构的抗静电SRPUF,其拉伸强度和断裂伸长率与未加抗静电剂的纯半硬质聚氨酯泡沫塑料(纯SRPUF)相比不发生明显下降.随填料用量的增加,SRPUF的硬度和模量增大,阻尼因子下降.     

矿用高分子泡沫材料抗静电研究

研究了抗静电剂及其协同作用对高分子(聚氨酯)泡沫的抗静电性能的影响。本实验讨论了抗静电剂A及十六烷基三甲基溴化铵对半硬质聚氨酯泡沫的体积电阻率(ρv)、表面电阻率(ρs)以及力学性能的影响。结果表明,以聚醚多元醇10 g为基准时,抗静电剂A和十六烷基三甲基溴化铵的同时使用,当抗静电剂A的用量为0.6 g和十六烷基三甲基溴化铵的用量为0.25 g时,聚氨酯泡沫的表面电阻率从7.33×1011Ω降低到6.1×108Ω。聚氨酯泡沫的表面电阻率可以降低到满足抗静电的需要,而同时其力学性能也达到行业的标准要求。     

聚氨酯泡沫中两种抗静电添加剂的协同效应研究

聚氨酯泡沫具有许多优良性能,应用广泛。但在使用过程中容易产生静电,需加入抗静电剂提高其抗静电性能。本实验以聚氨酯泡沫为材料,通过加入抗静电剂十六烷基三甲基溴化铵和导电炭黑两种抗静电剂探讨抗静电剂协同作用对聚氨酯泡沫发泡倍数、固化所需时间、力学性能、表面电阻率的影响,得出最优抗静电聚氨酯泡沫的配料比。     

聚氨酯／导电炭黑抗静电胶粘剂的制备与性能研究

制备了弹性聚氨酯（PU）/导电炭黑复合抗静电胶粘剂,通过体积电阻率的测定考察了该胶粘剂的导电性能,利用热重分析（TGA）和差示扫描量热（DSC）法研究了该胶粘剂的热性能,并采用湿热老化和温度冲击试验研究了该胶粘剂在加入复合抗氧剂前后的抗老化性能。结果表明：当呱导电炭黑）≥6．2％（相对于胶粘剂而言）时,该胶粘剂开始获得抗静电能力;当w（导电炭黑）≈7．0％（相对于胶粘剂而言）时,该胶粘剂的体积电阻率发生突跃式下降;该胶粘剂的热性能由PU基体所决定,导电炭黑对其热性能的影响不大;加入复合抗氧剂后,该胶粘剂具有良好的抗老化性能。     

聚氨酯/导电炭黑抗静电胶粘剂的制备与性能研究

制备了弹性聚氨酯(PU)/导电炭黑复合抗静电胶粘剂,通过体积电阻率的测定考察了该胶粘剂的导电性能,利用热重分析(TGA)和差示扫描量热(DSC)法研究了该胶粘剂的热性能,并采用湿热老化和温度冲击试验研究了该胶粘剂在加入复合抗氧剂前后的抗老化性能。结果表明:当w(导电炭黑)≥6.2%(相对于胶粘剂而言)时,该胶粘剂开始获得抗静电能力;当w(导电炭黑)≈7.0%(相对于胶粘剂而言)时,该胶粘剂的体积电阻率发生突跃式下降;该胶粘剂的热性能由PU基体所决定,导电炭黑对其热性能的影响不大;加入复合抗氧剂后,该胶粘剂具有良好的抗老化性能。     

导电炭黑对木粉/PP复合材料抗静电及力学性能的影响

文章对比分析了非离子型抗静电剂、高分子型抗静电剂与导电炭黑对木粉/PP复合材料的抗静电作用,重点探讨了导电炭黑的添加量对其抗静电及力学性能的影响。结果表明:与非离子型抗静电剂、高分子型抗静电剂相比,导电炭黑对木粉/PP复合材料的抗静电作用效果更优;当导电炭黑的添加量达到8份时,复合材料的表面电阻率和体积电阻率分别达到1.64×10~8?和2.54×10~8?·cm,具有较好的抗静电效果;在马来酸酐接枝聚丙烯(MAPP)的存在下,导电炭黑提高了木粉/PP复合材料的抗弯性能。     

抗静电高抗冲聚苯乙烯片材的研究

以高抗冲聚苯乙烯为基体、炭黑为导电填料,热塑性丁苯橡胶为增韧剂,制得抗静电高抗冲聚苯乙烯片材.通过表面电阻率的测试和SEM照片观测分析了影响表面电阻率的因素.结果表明:采用多相复合体系、低压缩比螺杆、低牵伸速度均有利于降低片材表面电阻率.     

复合导电聚合物导电机理的探讨

复合导电聚合物是以高聚物为基体,与各种导电物质(如金属,炭黑、炭纤维、余属氧化物等),通过分散复合、层积复合、电化学复合以及表面形成导电膜等方式而制得。电阻率可在很大范围内调节,按其不同的体积电阻值范围,可作不同的和途,见表     

抗静电聚醚型聚氨酯弹性体的合成及性能研究

采用半预聚物法,以聚醚多元醇PTMG1000、PTMG2000、330N、MDI为原料合成预聚体,以1,4-丁二醇(BDO)为扩链剂,测试了抗静电剂DE-8A、碳纳米管、导电炭黑对聚氨酯弹性体性能的影响。结果表明,不同的抗静电剂中,离子型抗静电剂易分散,抗静电效果较好,电阻率下降明显,且由于添加量少对弹性体的力学性能影响较小;碳纳米管和导电炭黑不易分散,达到相同的抗静电效果需要增加添加量,降低弹性体的力学性能。     

水发泡抗静电半硬质聚氨酯泡沫塑料的制备和性能研究

采用内部添加导电炭黑（CB）方法,通过一步法模塑成型工艺制备了不同导电炭黑或硬段（HS）含量的水发泡抗静电半硬质聚氨酯泡沫塑料（SRPUF）。测试了SRPUF的红外光谱、导电性能、力学性能和黏弹性。结果表明,随着导电炭黑或硬段含量的增加,SRPUF的体积电阻率下降;随着导电炭黑含量的增加,SRPUF的拉伸模量提高,拉伸强度和断裂伸长率显著下降;随着硬段含量的增加,SRPUF的拉伸和压缩模量增大,抗压能力提高,拉伸强度基本不变,而断裂伸长率显著下降;随着导电炭黑或硬段含量的增加,SRPUF的玻璃化转变温度（Tg）分别向低温和高温方向移动,动态模量则均在温度低于Tg时逐渐下降,温度高于Tg时逐渐提高。     

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。