填充床反应器中酶法合成生物蜡酯

研究了填充床式反应器酶法合成生物蜡酯的生产工艺。以大豆油、十六醇为原料,在石油醚体系中,使用实验室自制的固定化Candida sp.99-125为催化剂。对操作参数,如填充高度、进料速度、固定化酶用量、底物摩尔比进行了研究。结果表明,固定化酶质量为47 g,填充高度40 cm（内径3.5 cm）,油醇摩尔比1∶2.4,以4 mL/min速度进料保留时间4 h,产率可达83%。固定化酶在使用16批时,产率仍保持在70%以上。同时,对于填充床的填充方式作了初步探索。     

棕榈油碱催化制备生物柴油实验研究

用氢氧化钾作催化剂,考察了反应温度、催化剂用量、醇油摩尔比、反应时间对棕榈油和甲醇制备生物柴油产率的影响。结果表明,最佳反应条件为:反应温度40℃,催化剂用量0.6%,醇油摩尔比6∶1,反应时间2.0 h。此时,生物柴油产率可达97.82%。     

棕榈油碱催化制备生物柴油实验研究

用氢氧化钾作催化剂,考察了反应温度、催化剂用量、醇油摩尔比、反应时间对棕榈油和甲醇制备生物柴油产率的影响。结果表明,最佳反应条件为:反应温度40℃,催化剂用量0.6%,醇油摩尔比6∶1,反应时间2.0 h。此时,生物柴油产率可达97.82%。     

月桂酸单甘酯的催化合成

文章以磷钨酸为催化剂,4分子筛为脱水剂,在无溶剂条件下月桂酸和甘油为原料合成月桂酸单甘酯,考察了反应温度、摩尔比（月桂酸/甘油）、反应时间、催化剂用量、分子筛用量对反应产率的影响,并确定了反应最佳条件是：反应温度200℃,摩尔比（月桂酸/甘油）1∶2.5,反应时间为2 h,磷钨酸用量为3%,分子筛用量为5%（月桂酸与...     

丙烯酸十四酯的合成

以丙烯酸和十四醇为原料,经酯化反应直接合成丙烯酸十四酯。探讨了丙烯酸与十四醇摩尔比,催化剂和阻聚剂的用量、反应温度及反应时间对酯化反应的影响。得出合成丙烯酸十四酯的最佳合成条件:丙烯酸与十四醇摩尔比为1 1,对甲苯磺酸用量为0 8%,对苯二酚用量为0 6%,反应温度为120℃,反应时间为4h。在此反应条件下,酯化产率可达99%。酯化产物经熔点、元素分析、红外光谱及核磁共振谱图分析证明所得产物为丙烯酸十四酯。     

无溶剂体系中共吸附固定化脂肪酶催化合成植物甾醇酯

以大孔树脂NKA吸附固定化脂肪酶为催化剂,以月桂酸和植物甾醇为反应物,在无溶剂体系中合成植物甾醇酯;以NKA为载体共吸附固定葡聚糖与酶,考察了反应温度、底物摩尔比、糖种类及葡聚糖添加量和反应时间对酶催化性能的影响. 结果表明,在酸/醇摩尔比6:1、葡聚糖与酶共同吸附固定时分子量为10 kDa的葡聚糖添加量为酶量7.5%的条件下,60℃下反应12 h,酯化率高达96.2%,酯化反应时间比简单吸附固定化酶缩短4 h.     

固体酸催化废油酯制备脂肪酸丁酯

研究以废油酯为原料在固体酸催化作用下与丁醇酯交换反应制备脂肪酸丁酯的过程,采用气相色谱对脂肪酸丁酯的含量进行分析。考察了醇油摩尔比、催化剂用量、反应温度和反应时间对酯化反应转化率的影响。结果表明,该反应的最适宜工艺条件为：醇油摩尔比16∶1,催化剂用量1.2%,反应温度115℃,反应时间4 h。废油酯在最优工艺条件下,经过酯交换反应得到的转化率超过83%。     

无溶剂合成硬脂酸月桂醇酯的研究

在无溶剂存在、微波辐射协助下,以对甲苯磺酸(PTSA)为催化剂,4A分子筛作脱水剂,以月桂醇和硬脂酸为原料快速合成了硬脂酸月桂醇酯.讨论了醇酸物质的量比、微波功率、辐射时间和催化剂用量对反应的影响.经正交实验得出合成最佳条件为:醇酸摩尔比1∶1.1、PrSA占原料总质量的1.5%、微波功率270±10 W、辐射时间20 min,产率可达95%.     

酶促泔水油生产生物柴油条件的研究

以泔水油资源转化为宗旨,利用中性脂肪酶催化泔水油与甲醇反应制备生物柴油。通过50g泔水油正交实验获得最佳转酯化反应条件：油醇摩尔比1∶3,油酶质量比1∶1,温度45℃,油溶剂质量比1∶0.6,反应时间10h后,生物柴油产率可达89.7%以上。对生物柴油密度、黏度、馏程、凝固点、硫含量、残碳、十六烷值等多项指标进行检测,油品的质量符合我国生物柴油的标准。在优化条件的基础上进行10L和50L反应釜实验,10h生物柴油的产率达到80%以上。     

相转移催化大豆油醇解研究

通过催化大豆油与甲醇进行酯交换反应合成脂肪酸甲酯(FAME),研究了相转移催化剂对油脂醇解的催化性能。考察了不同醇油摩尔比、催化剂用量、反应时间和反应温度对大豆油醇解反应的影响,得到了较佳工艺条件:n(甲醇)∶n(大豆油)为6∶1,催化剂用量为大豆油质量的1.0%,35℃~40℃下反应1 h。结果表明:苄基三乙基氢氧化铵是油脂醇解的有效催化剂,在优化工艺条件下甲酯产率达91%以上。     

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。