联苯锅炉预抽真空技术

介绍一种联苯锅炉预抽真空技术,即在室温和低温离加热(70℃或50℃)过程中对联苯锅炉抽真空,然后加热至联苯气化温度,最后用联苯蒸气对生产设备进行升温。使用该方法降低了联苯气化温度,缩短了联苯加热时间,消除了联苯拔气造成的环境污染,开车升温耗电节约60%。     

合成导热油DBT在纺丝中的应用

<正> 化纤厂熔融纺丝系统中,纺丝箱是保证丝束成形的关键设备。为稳定纺丝温度,纺丝箱内通入合成导热油加热,目前通常采用的品种是联苯-联苯醚混合物。加热方式有两种,一是气/液相加热,二是由锅炉发生联苯-联苯醚蒸汽进行气相加热。该品种的主要缺点是沸点低(255-257℃),蒸汽压较高,在纺丝箱温度300℃操作时蒸汽压超过0.24MPa.增加了从纺丝箱泄漏的儿率。而联苯-联苯醚的闪点仅115-124℃,稍有泄漏易产生火灾危险,而且其味恶臭难闻,会影响操作环境和人体健康。因此能克服上述问题的导热油将成为化纤工业新颖优良的热媒。     

小经验--合成导热油DBT在纺丝中的应用

化纤厂熔融纺丝系统中,纺丝箱是保证丝束成形的关键设备.为稳定纺丝温度,纺丝箱内通入合成导热油加热,目前通常采用的品种是联苯-联苯醚混合物.加热方式有两种,一是气/液相加热,二是由锅炉发生联苯-联苯醚蒸汽进行气相加热.该品种的主要缺点是沸点低(255～257℃),蒸汽压较高,在纺丝箱温度300℃操作时蒸汽压超过0.24MPa,增加了从纺丝箱泄漏的几率.而联苯-联苯醚的闪点仅115～124℃,稍有泄漏易产生火灾危险,而且其味恶臭难闻,会影响操作环境和人体健康.因此能克服上述问题的导热油将成为化纤工业新颖优良的热媒.     

聚酯装置中气相热媒系统的设计与应用

介绍了气相热媒介质联苯-联苯醚共沸混合物的物理性质和使用要求;分析了在聚酯装置中气相热媒系统的设计与控制方案。提出在气相热媒系统设计中,应减少热媒泄漏,采取程序化升温,先快速升温到216℃,然后缓慢升温至270～295℃;在其配管设计中,要考虑每段管道的特殊性,减少凝液直接回流至热媒蒸发器,一次热媒的流向为蒸发器的下部进、上部出的方式;在聚酯装置开车时,气相热媒的加热应采取液相温度和气相压力共同控制的方法,保证热媒蒸发器的稳定性。     

微型流化床与热重测定煤焦非等温气化反应动力学对比

利用微型流化床反应分析仪(MFBRA)和热重分析仪(TGA)比较煤焦与CO₂的非等温气化反应特性,并利用单一升温速率法和组合升温速率法计算反应动力学数据。结果表明:升温速率对半焦非等温气化过程有重要影响,随着升温速率的增大,起始反应温度和最大反应速率对应的气化温度增加,同一气化温度下的碳转化率降低,而且利用单一升温速率法求取气化反应的活化能逐渐减小。与TGA相比,同一升温速率下,MFBRA中半焦气化反应的起始反应温度和最大反应速率对应的反应温度明显较小,而且升温速率越大差异越显著。无论是单一升温速率法(升温速率≥5℃·min^-1)还是组合升温速率法,TGA测得的动力学数据均明显小于MFBRA测得的动力学数据。高升温速率下(升温速率≥5℃·min^-1)半焦在TGA和MFBRA中非等温气化行为和动力学数据的差异很可能与MFBRA内较好的热量传递和受扩散的抑制作用较小有关。     

生物质焦CO2高温气化反应动力学研究

利用同步热分析仪,采用程序升温法研究了生物质焦CO₂气化反应速率特性,主要考察了升温速率对生物质焦气化反应性的影响,并用Friedman-Reich-Levi法对其动力学参数进行了计算。结果表明：DTG曲线峰值温度和最大反应速率随着升温速率的增大而增大;以二氧化碳作保护气,改变升温速率,当升温速率为15 ℃/min时,热解得到的生物质焦的反应活性最好,即气化速率最快;升温速率越大,反应速率随着温度的变化越明显;生物质焦气化阶段的活化能在-4 984.41~1 408.39 kJ/mol之间变化,气化的反应过程复杂。     

晋城无烟煤与杨树木屑共气化特性

为分析生物质对晋城无烟煤气化过程的影响,以晋城无烟煤和杨树木屑为试验对象,研究无烟煤、脱灰无烟煤与木屑在气化介质CO2下的共气化特性,通过热重分析法考察了木屑掺混比、升温速率、煤样脱灰处理等因素对气化过程的影响。结果表明,掺混生物质木屑能降低无烟煤、脱灰无烟煤共气化温度,且增加生物质掺混比例能显著降低起始反应温度;脱灰无烟煤共气化反应起始温度更低。10、20℃/min升温速率下共气化试验结果表明,升温速率对共气化过程有一定影响;低升温速率下开始气化反应温度低,高升温速率下最大质量变化速率值大;煤样脱灰处理后,失去矿物质使煤孔结构发达,生物质与气化剂反应活位点增加,能提高气化反应性。     

阻燃异形涤纶FDY长丝工艺探索

探讨了用TCS法生产阻燃异形涤纶长丝时,切片含水率、纺丝温度、冷却成形、拉伸等工艺参数的选择。结果表明:采用合理的干燥工艺可获得含水率稳定在18μg/g以内的阻燃干切片,1#联苯锅炉温度控制在268~270℃,2#联苯锅炉温度控制在270~272℃,热管温度为168~172℃,卷绕速度为4.4~4.6km/min时,可生产出质量优良的阻燃异形涤纶长丝。     

热管拉伸法生产阻燃涤纶长丝工艺研究

探讨了用热管拉伸(TCS)法生产阻燃涤纶长丝时,切片含水率、纺丝温度、冷却成形、拉伸等工艺参数的选择。结果表明:采用合理的干燥工艺可获得含水率稳定在1.8×10-5以内的阻燃干切片;1#联苯锅炉温度控制在270￣272℃,2#联苯锅炉温度控制在274￣276℃;加强冷却条件;热管温度为167￣173℃,卷绕速度为4.3￣4.5km/min时,可生产出质量优良的阻燃涤纶长丝。     

细旦阻燃涤纶FDY工艺研究

探讨了用TCS法生产细旦阻燃涤纶长丝时,切片含水率、纺丝温度、冷却成形、拉伸等工艺参数的选择。结果表明:采用合理的干燥工艺可获得含水率稳定在18×10-6以内的阻燃干切片,1#联苯锅炉温度控制在267~268℃,2#联苯锅炉温度控制在268~270℃,热管温度为167~169℃,卷绕速度为4.1~4.3 km/m in时,可生产出品质优良的细旦阻燃涤纶长丝。     

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。