中间相沥青调制—热解

文章采用以萘和三氟化硼与氟化氢为原料制备的齐聚物沥青,研究齐聚物沥青在中温条件下通过热缩聚制备出的低软化点,中间相含量高,纺丝性能良好的中间相沥青,探讨齐聚物沥青调制的时间,热缩聚反应的时间以及热缩聚反应的温度对于中间相沥青的影响。     

原料及缩聚条件对中间相沥青性质的影响

本研究用刮膜蒸发器对制备中间相沥青的原料（软化点为６０℃的石油沥青）进行了分离，并分别以未分离的沥青及分离出的重质沥青为原料在不同的条件下调制成中间相沥青。探讨了原料分子量分布及缩聚过程中温度、Ｎ２流量、缩聚时间对中间相沥青族组成分布、软化点和可纺性等性质的影响。     

沥青－重油共炭化制取中间相沥青基炭纤维初探

利用工业重油三线芳烃和煤焦油沥青共炭化改善沥青的炭化性质，调制可纺性中间相沥青。本文主要考察了共炭化反应条件对沥青改性的影响，不同热缩聚条件与所得中间相沥青的软化点，光学各向异性含量和可纺性的关系，并对中间相沥青进行初步熔纺及后处理，制得强度较高的炭纤维，讨论了由此途径制取高性能沥青基炭纤维的工艺特点。     

中间相沥青基中空炭纤维的制备及其性能的研究

利用狭缝形喷丝板，将热缩聚和催化缩聚两种不同方法制得的中间相沥青纺制成中空纤维。着重研究了热缩聚法中间相沥青制得的中空炭纤维的力学性能。研究表明，中空炭纤维的力学性能比实心炭纤维显著提高。本文对这种提高的原因进行了分析。     

中间相沥青炭纤维研究

本文采用石油重质渣油，通过加压－减压两段热缩聚方法调制中间相沥青，并对其进行了收率测算，元素分析，红外光谱分析、热台偏光显微镜观查等，研究了其组成和结构。将上述纤维经单孔纺丝、预氧化、炭化处理后，利用扫描电镜研究了所得炭纤维的横截面形态结构。实验结果表明：两段式热缩聚可获得中间相含量高、收率、热稳定性及可纺性好的中间相沥青。由该沥青制备的炭纤维横截面呈洋葱皮形态结构，平均直径１０μｍ，拉伸强度１．７８８ＧＰａ，断裂伸长１．１％。     

煤焦油与石油焦油热缩聚的比较研究

分别以煤焦油为原料,在430℃热缩聚50min-270min和以石油渣油为原料在310℃热缩聚130min-370min制备了一系列具有软化点的煤焦油沥青和石油沥青。通过元素分析、软化点、族组成、偏光光学和NMR对原料与沥青的结构进行了分析。在1．6MPa,480℃下将改质煤焦油尖 和石油沥青进行焦化,考察了焦收率和光学组织结构变化情况。结果表明,热缩聚可提高煤焦油沥青和石油沥青的软化点、不溶物含量和焦收率,煤焦油沥青与石油沥青成焦后均生成各向异性广域光学结构。     

热缩聚法制备包覆沥青的基础研究

包覆沥青对提高锂离子电池负极材料的性能起到重要作用。以乙烯渣油沥青为原料,通过常压热缩聚法制备包覆沥青。考察了反应温度、反应时间对包覆沥青的基础指标(软化点、甲苯不溶物、喹啉不溶物和结焦值)和光学显微结构的影响。研究结果表明：以N₂作为保护气体,当热缩聚反应温度为390℃,反应时间为4 h的条件下,制备出了软化点为200℃,甲苯不溶物为35.47%,喹啉不溶物为1.11%,结焦值为67%的各向同性沥青。通过FTIR和TGA分析可知,乙烯渣油沥青和高软化点各向同性沥青的芳香性指数(Iar)分别为0.526 6和0.5377,在700℃热解残余质量分别为20.22%和50.79%。表明乙烯渣油沥青通过热缩聚处理后得到的高软化点各向同性沥青具有较高的芳香性和良好的热稳定性,是一种优质的包覆沥青。     

煤直接液化沥青制备中间相沥青炭纤维的研究北大核心

中间相沥青基炭纤维的性能直接取决于纺丝用中间相沥青,煤直接液化沥青因其饱和烃含量高,氢碳比高,高温融变性好,硫含量低等优点成为制备纺丝用中间相沥青的优良前驱体。本文以煤直接液化沥青为原料,研究不同热缩聚工艺对中间相沥青组成和结构的影响,通过考察其偏光织构、软化点、喹啉不溶物含量、黏温曲线和纺丝时长等指标综合评价可纺性。采用高低温结合多段聚合工艺制得具有大融并体结构、可纺性优良的中间相沥青,并进一步制得具有理想微观形貌的纤维,其拉伸强度为2.03 GPa,拉伸模量达到581 GPa。     

刮膜蒸发器在中间相沥青制备中的应用研究

本研究在国内首次采用刮膜蒸发法分离制备中间相沥青的原料－石油催化裂化渣油，对刮膜蒸发法和真空蒸馏法的分离效率和能耗等进行了比较，实验考察了刮膜蒸发器在分离过程中进料温度，进料量，壁面温度和刮板转速对分离效果及总传热系数的影响，模索出刮膜蒸发法分离石油催化裂化渣油及低软化点沥青物系比较适宜的工艺条件。     

中间相沥青的纺丝—中间相沥青的成纤及碳纤维的结构

考察了几种不同缩聚条件下所得中间相沥青的熔纺过程,发现挤出沥青丝在喷丝板毛细孔口处的胀大率(d_m/d_0)及其最大拉伸比(V_LV/_0)max与喷丝板毛细孔径及纺丝温度有关。 中间相沥青的软化点及β树脂(BI—PS)直接决定了熔融沥青的表现粘度和拉伸粘度,对最大拉伸比(V_L/V_0)max具有显著的影响。 在相同的熔纺条件下,从T渣油中间相沥青制备的碳纤维显示了放射型横截结构,但从美A240中间相沥青制得的碳纤维却显示了乱层型横截结构,说明了碳纤维的横截结构受到中间相沥青组成的强烈影响。     

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.