煤基管状炭膜支撑体的研究(Ⅱ)制备工艺条件对支撑体孔结构性能的影响

探讨了制备工艺条件对炭膜支撑体孔结构性能的影响。研究表明：提高成型压力可使支撑体的平均孔径减小;提高炭化升温速率则使支撑体的平均孔径增大;随着炭化终温的升高,支撑体的平均孔径出现极大值。     

糠醇单体制备支撑炭分子筛膜

使用糠醇单体在多孔氧化铝管的内表面成功制备了炭分子筛膜。其制备采用了3种方法:(Ⅰ)将酸性催化剂加入到糠醇中使糠醇聚合,然后采用浸渍法涂膜;(Ⅱ)先将催化剂浸渍在支撑体上,然后将支撑体浸入到糠醇溶液中制膜;(Ⅲ)先将催化剂浸渍在支撑体上,然后将支撑体置于糠醇蒸汽中制膜。方法Ⅱ制备的炭膜质量最大。方法Ⅲ制备的炭膜质量次之,方法Ⅰ制备的炭膜质量最小。方法Ⅲ制得的炭膜具有最好的气体选择性,CO2/N2的理想选择性为79.3,O2/N2的理想选择性为10.6,方法Ⅰ、Ⅱ制得的炭膜的气体分离性能相近,CO2/N2的理想选择性为20,O2/N2的理想选择性为6。     

煤基管状炭膜支撑体的研究(Ⅰ)原料性质对支撑体孔结构性能的影响

通过对不同种类的煤制取炭膜支撑体效果、原料的颗粒度和粘结剂对支撑体孔结构性能影响的研究,探讨了用煤制取炭膜支撑体的可行性。研究表明：选择适宜的煤种完全可以制备出孔结构性能良好的炭膜支撑体;粘结剂不仅可以改善支撑体的强度,而且还可以起调孔和造孔的作用;选择不同的原料粒度可以制备出满足不同平均孔径的炭膜支撑体。     

炭化条件对多孔炭膜性能的影响

以石油沥青为原料,采用无粘结剂成型制备多孔炭膜,考察了炭化条件对炭膜的Ｈ２和Ｎ２气体渗透率和理想分离系数的影响,并用压汞法表征了炭膜的孔径分布,结果表明：炭化温度是影响炭膜性能的关键因素,制备的炭膜具有均匀性孔径分布,平均孔径为１５３ｎｍ。     

高性能炭分子筛膜支撑体的制备研究

采用湿法球磨与粒子烧结相结合的方法,以α-Al2O3为主要原料,干压成型法制备出性能较高的炭分子筛膜支撑体.经过各种表征手段分析,所得支撑体具有均布的孔隙结构和较窄的孔径分布,并探讨了致孔剂种类、干燥制度、烧结温度及球磨时间对炭分子筛膜支撑体性能的影响.结果表明,1 250℃下烧结然后保温2h、球磨时间为4h时,制备的高渗透通量炭分子筛膜支撑体平均孔径为0.4μm、孔隙率为46％.     

沥青基炭膜的制备研究

以煤沥青为原料经热处理、预氧化和炭化等工艺制备了炭膜,研究了制备条件对炭膜性能的影响及其气体分离的机理。结果表明,制备炭膜的最佳条件是热处理温度３７０℃,时间１２０ｍｉｎ;预氧化温度２２０℃,时间１２０ｍｉｎ,炭化温度９００℃。炭膜的气体分离机理是努森扩散,在高压差时伴有粘性流。     

煤基管状炭膜支撑体的研究（II）制备工艺条件对支撑体孔结构性能的影响

探讨了制备了工艺条件对炭膜支撑孔结构性能的影响，研究表明，提高成型压力可使支撑体的平均孔径减小，提高炭化纤维速率则使支撑体的平均孔径增大；随着炭化终温的升高，支撑体的平均孔径出现极大值。     

煤基管状炭膜支撑体的研究（I）原料性质对支撑体孔结构性能的影响

通过对不同种类的煤制取炭膜支撑体效果,原料的颗粒度和粘结剂对支撑体孔结构性能影响的研究,探讨了用煤制取炭膜支撑体的可行性,研究表明：选择适宜的煤种完全可以制备出孔结构性有良好的炭膜支撑体,粘结剂不仅可以改善支撑体的强度,而且还可以起调孔和造孔的作用,选择不同的原料粒度可以制备出满足不同平均孔径的炭膜支撑体。     

聚醚砜酮基炭膜的制备及其气体分离性能

采用浸渍涂膜法,以商用聚醚砜酮(PPESK)为前驱体制备了管式复合炭膜,考察了涂膜次数、改性剂及其加入量对所制备炭膜的气体分离性能的影响.结果表明,随着涂膜次数增多,气体分子的渗透速率逐渐减小而选择性呈增大趋势;加入改性剂后的复合炭膜渗透速率和分离系数均有不同程度的提高,表明改性剂不仅改善了涂膜液与支撑体之间的复合效果、减少涂膜次数,同时也促进了气体渗透速率的提高.利用扫描电镜对复合炭膜的微观形貌进行观测,可以看出,复合炭膜由支撑体和分离膜层2部分组成.膜表面很致密均匀,无明显缺陷,分离层薄而均一,厚度在5μm左右,且与支撑体结合紧密.     

ZSM-5改性酚醛树脂基多孔炭膜的微观结构研究

以ZSM-5掺杂改性酚醛树脂为前驱体,经成型和900℃热解制备了多孔炭膜。采用热失重分析、扫描电镜、X射线衍射、红外光谱与泡压法等表征手段分别对前驱体热稳定性、炭膜表观形貌、晶体结构、表面官能团与孔隙结构进行了表征。考察了ZSM-5用量对前驱体热稳定性、炭膜孔径、孔隙率的影响。结果表明,经ZSM-5改性后前驱体膜残炭量显著提高;热解后ZSM-5结构保留完好,其会促进酚醛树脂的热分解同时阻碍炭结构的热缩聚重排,有利于形成更多小孔径孔隙结构的乱层炭结构。     

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.     

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.