固体超强碱催化合成蔗糖硬脂酸酯

利用固体超强碱催化剂合成蔗糖硬脂酸酯,考察了反应时间、反应温度、原料配比以及催化剂用量对蔗糖硬脂酸酯产率的影响,得出最佳合成条件为：硬脂酸甲酯：蔗糖(摩尔比)=2∶1；催化剂用量为原料总量的6％；反应时间8 h；反应温度130～140℃。     

TiGeW_(12)O_(40)/TiO_2微乳化法合成蔗糖酯

以硬脂酸甲酯与蔗糖为原料,在催化剂TiGeW12O40/TiO2和乳化剂的作用下进行酯交换反应合成蔗糖酯,详细考察了乳化剂和催化剂用量、反应温度、原料配比等因素对合成蔗糖酯的影响。结果表明,较佳合成工艺条件为:硬脂酸甲酯∶蔗糖(摩尔比)=2∶1,乳化剂选用十二烷基硫酸钠,用量为投放总量的6%,催化剂占总质量的1.5%,反应温度120～130℃,反应时间3h,得到一酯,二酯的混合蔗糖酯。     

蔗糖-6-苯甲酸酯的制备

以蔗糖为原料,苯甲酸甲酯为酯化试剂,使用碳酸铯为催化剂合成蔗糖-6-苯甲酸酯。探讨了催化剂用量、反应温度、反应时间和物料配比对反应的影响。最优的反应条件:催化剂质量分数为2%(以蔗糖质量计,下同),n(蔗糖):n(苯甲酸甲酯)=1:4,反应温度为45℃,反应真空度为0.05 MPa,反应时间为5 h,蔗糖-6-苯甲酸酯的收率可达81.0%。     

无溶剂法合成蔗糖硬脂酸酯的工艺研究

以乙醇代替有毒的甲醇与硬脂酸在酸催化下进行反应制出了硬脂酸乙酯。以硬脂酸乙酯与蔗糖为原料在催化剂和乳化剂的作用下，进行酯交换反应合成出蔗糖硬脂酸酯。详细考察了该合成反应过程中乳化剂、催化剂用量，反应温度，原料配比，反应时间等因素对蔗糖硬脂酸酯产率的影响，得出了较佳合成工艺条件，即硬脂酸乙酯：蔗糖摩尔比为2．15：1，乳化剂与蔗糖质量比为0．1：1，催化剂与反应物料质量比为0．14：1，反应温度－120℃，压力－4．35kPa,反应时间－3.5h。以蔗糖计，蔗糖酯产率约75．2％。此外，还把蔗糖硬脂酸酯制成易挥发衍生物，建立了分析其组成的气相色谱方法。     

二丁基氧化锡催化酯交换合成硬脂酸异辛酯的研究

以硬脂酸甲酯和异辛醇为原料,二丁基氧化锡(n-Bu2SnO)为催化剂,通过酯交换法合成了硬脂酸异辛酯。考察了反应温度、催化剂用量,反应时间及物料配比等因素对酯交换反应的影响,并考察了催化剂重复使用情况。常压下,反应温度为140℃,n-Bu2SnO与硬脂酸甲酯的摩尔比0.011 4∶1,硬脂酸甲酯与异辛醇摩尔比1∶1.5,反应2 h条件下,硬脂酸异辛酯收率达到89.0%。n-Bu2SnO循环使用5次后,催化活性基本不变。对反应前后n-Bu2SnO的IR和XRD结构表征表明它具有很好的稳定性。     

硬脂酸蔗糖酯的合成及工艺优化

以碳酸钾为催化剂,在丙二醇溶剂中,通过硬脂酸乙酯与蔗糖反应,得到硬脂酸蔗糖酯,采用气相进行含量的分析。研究了温度、摩尔比（硬脂酸乙酯：蔗糖、蔗糖：丙二醇）、催化剂用量、反应时间等5个因素对反应的影响。选用L16（5^＋）正交实验,得到合成硬脂酸蔗糖酯的最佳条件为：蔗糖和硬脂酸乙酯摩尔比1．4：1、蔗糖和丙二醇摩尔比为1：17、温度70℃、反应时间9h、催化剂用量1．5％时,蔗糖酯的含量为93．96％。     

非催化合成硬脂酸甲酯

以硬脂酸为原料,先与氯化亚砜反应生成硬脂酸酰氯,不需分离,再直接与甲醇反应,非催化条件下合成硬脂酸甲酯。采用正交设计考察了温度、原料配比、反应时间对酯化率的影响,得到了最优化的工艺条件:反应温度70℃,n(硬脂酸)∶n(氯化亚砜)∶n(甲醇)=1∶1.4∶1.4,反应时间为2.5h,硬脂酸酯化率达99.3%。     

高单酯含量蔗糖酯的无溶剂制备

通过把微细蔗糖和硬脂酸甲酯制成粗分散体系(粒径小于10μm),用无溶剂法制备出了单酯含量高达79.8%的蔗糖酯。与其他典型的方法不同,该方法仅用4%的皂就可使硬脂酸甲酯转化率超过99%,大大减少了皂的用量。而且用相同量的皂就可制备出不同单酯含量的蔗糖酯,产率最高可达62.4%。考察了这种新反应体系的温度、催化剂量、皂的量和反应时间等不同条件下硬脂酸甲酯的转化率,还测定了不同单酯含量蔗糖酯的亲水亲油平衡(HLB)值、表面张力、界面张力和临界胶束浓度,揭示了它们之间的相互关系。     

一缩二乙二醇二硬脂酸酯的合成

以一缩二乙二醇和硬脂酸为原料,进行酯化反应,合成医药缓释剂一缩二乙二醇二硬脂酸酯,考察了物料配比、反应时间、反应温度对产品纯度和收率的影响。结果表明,最佳工艺条件为:一缩二乙二醇∶硬脂酸=1∶2.2(摩尔比),反应时间4 h,反应温度140℃。该工艺可使产品的收率大于92%。     

聚乙二醇硬脂酸酯的合成

以硬脂酸为基本原料,通过酰氯化后所得硬脂酰氯,再与聚乙二醇(400)进行酯化反应合成聚乙二醇(400)硬脂酸酯非离子表面活性剂。探讨了物料配比、反应时间、温度对合成反应的影响。合成反应的最佳条件为:反应温度为100℃,时间为1.0h,硬酯酰氯:聚乙二醇=1.1:1(摩尔比)。     

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。