POSS/PMMA纳米复合材料的制备及性能研究

采用八乙烯基倍半硅氧烷(OV-POSS)通过原位聚合法制备了具有交联网状结构的POSS/PMMA纳米复合材料。通过FT-IR、DSC等方法对纳米复合材料的结构和性能进行了表征。结果表明,通过原位聚合法制备的POSS/PMMA纳米复合材料具有交联网状结构,POSS的引入能明显改善材料介电性能和热学性能,但当OV-POSS含量较高时,热学性能有所下降。当POSS的用量为0.6%时,POSS/PMMA纳米复合材料的介电常数从2.91降低至2.77,介电损耗从0.0088降低至0.0039,复合材料的Tg也上升了。     

POSS/丙烯酸酯复合材料的合成及在疏水中的应用研究进展

多面体低聚倍半硅氧烷(POSS)由于其纳米级有机-无机结构,且纳米级别的无机核被有机官能团包围,使其成为构建纳米杂化材料和纳米复合材料的理想结构,引起了广泛的关注。本文综述了POSS用于增强疏水性能的丙烯酸酯聚合物复合材料的最新进展,重点介绍了POSS作为疏水单元,采用物理或共聚的方法与丙烯酸酯复合,合成不同结构的POSS/丙烯酸酯复合材料,以满足所需的疏水要求。POSS/丙烯酸酯复合材料具有良好的疏水性能,同时具有优异的物理性能。     

POSS/聚合物纳米材料的制备方法及应用

本文介绍了POSS/聚合物纳米复合材料的几种制备方法及POSS纳米复合材料在航天航空,生物医药,多孔材料和光固化材料等方面的应用。     

EP/POSS/SiO2纳米复合材料性能研究

以自制的两种不同黏度的环氧基倍半硅氧烷(POSS)为改性剂,对双酚A型环氧树脂(EP)/4,4’–二氨基二苯砜(DDS)进行改性,制备EP/POSS杂化材料。再以纳米SiO2为填料制备了EP/POSS/SiO2纳米复合材料。结果表明,与EP相比,杂化材料和纳米复合材料的弯曲强度和弯曲弹性模量都有所提高,其中纳米复合材料(分别添加低黏度和高黏度的POSS)的弯曲弹性模量分别提高了15.03%和9.44%,添加高黏度的POSS和纳米SiO2后其杂化材料和纳米复合材料体系的弯曲强度均有所提高,杂化材料和纳米复合材料的最大分解温度和在高温时的热残留量都有所提高。     

纳米技术在阻燃聚丙烯中的研究进展

综述了纳米无机阻燃剂在阻燃聚丙烯(PP)中的研究进展,主要包括 PP/纳米级金属氢氧化物复合材料、PP/碳纳米管复合材料、PP/蒙脱土纳米复合材料和 PP/POSS 纳米复合材料。     

POSS/聚合物复合材料的研究进展

介绍了POSS/聚合物复合材料的基本特性,以及常见的几种制备方法 (物理共混法和化学共聚法),指出了POSS/聚合物复合材料相对于常规纳米高分子复合材料在性能上的差异。对POSS/聚合物复合材料在发展过程中存在的一些问题进行了分析并展望了发展趋势。     

POSS/PU-PS的合成表征与热性能研究

采用化学键接入聚合物网络结构的方法,以POSS(OH)_3为基体,通过与MDI(4,4'-二苯基甲烷二异氰酸酯)和1,4-丁二醇进行合成,得到含氨基甲酸基的POSS(聚笼型倍半硅氧烷),再将产物与2-溴代异丁酰溴进行合成,产物为POSS/PU-Br,再利用ATRP法制备POSS/PU-PS纳米复合材料。利用FTIR和~1H-NMR手段表征POSS/PU-PS复合材料结构,利用DSC、TGA对该材料的热性能进行研究。结果表明:我们成功地合成出POSS/PU-PS纳米复合材料,并且具有良好的热性能。     

POSS/PS纳米复合微球的制备与热性能研究

采用乳液共聚法合成了POSS/PS纳米复合微球,研究了反应条件对复合材料热性能的影响.结果表明,合成的微球形态规则、尺寸分布较均匀,微球具有核壳型结构,尺寸可调,微球尺寸可控制在50nm左右.通过共聚引入刚性POSS结构,使得POSS/PS纳米复合材料的玻璃化温度显著高于纯PS,耐热性明显改善.     

交联网状结构POSS/PMMA纳米复合材料的研究

采用八甲基丙烯酰氧丙基POSS通过原位聚合法制备了交联网状结构的POSS/PMMA纳米复合材料,并采用FT-IR、XPS、SEM、TG、DSC等方法对其结构和性能进行表征。结果表明,POSS/PMMA纳米复合材料具有交联网状结构;POSS的加入对PMMA可见光的透过性无影响;当POSS的摩尔分数为0.6%时,相对于PMMA,复2合材料的拉伸强度和模量分别提高了24.7MPa和0.89GPa,冲击强度提高了6.2kJ/m,弯曲强度和模量分别提高了19.7MPa和1.71GPa,断裂伸长率略有降低。复合材料的热稳定性和T有所提高,但初始分解温度略有下降。g     

多面体低聚倍半硅氧烷研究的最新进展

多面体低聚倍半硅氧烷（POSS）是目前研究相当活跃的一类有机—无机杂化结构的纳米粒子。通过官能化POSS直接聚合或利用化学反应将POSS结合到聚合物中以及作为纳米添加剂与其他材料共混,可制备多种多样的聚合物/POSS纳米复合材料。POSS的引入能有效降低材料的介电常数,改善材料的热性能、机械性能、耐火性、防水防油性、加工性能、牢固度和透明度等;因此,POSS被认为是一种优良的纳米构筑材料。本文对POSS研究的近况进行了简要概述。     

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。