几种合成聚丁二酸丁二酯用催化剂的催化效果比较

以1,4-丁二酸和1,4-丁二醇为原料,分别以SnCl2,异辛酸亚锡[Sn(Oct)2],ZnCl2,乙酸锌[Zn(OAc)2],Sb2O3和SO42–/ZrO2固体超强酸为催化剂,采用直接熔融缩聚法合成了聚丁二酸丁二酯(PBS)。通过测试酯化反应阶段的出液量、PBS的收率及其特性黏度、数均分子量和熔融温度等性质,比较了6种催化剂在PBS聚合反应中的催化效果。以SnCl2为例,利用傅立叶变换红外光谱和热重分析研究了由其催化合成的PBS的结构和热稳定性能。结果表明,实验合成的产物为羟基封端PBS;6种催化剂都能促进1,4-丁二酸和1,4-丁二醇分子间的脱水酯化反应,除Sn(Oct)2外,其它几种催化剂均能有效减少四氢呋喃副产物的生成;锡类化合物的催化效果总体上最好,其中SnCl2作催化剂时所合成的PBS的收率、特性黏度、数均分子量和熔融起始温度最高,其热分解温度为280℃。以PBS分子量为指标,6种催化剂的催化效果高低顺序为:SnCl2Sn(Oct)2Sb2O3SO42–/ZrO2ZnCl2Zn(OAc)2。     

棕榈酸1,4-丁二醇二酯的合成

在棕榈酸/十二烷基苯磺酸(DBSA)/水微乳液中,研究了DBSA催化下棕榈酸和1,4-丁二醇的酯化反应,合成了标题化合物.考察了物料配比、酯化时间、酯化温度和催化剂用量对酯化率的影响,确定了最佳工艺条件,在n(1,4-丁二醇)∶n(棕榈酸)=5∶1,酯化时间2.5 h,酯化温度70 ℃,DBSA的用量为棕榈酸物质的量的3%时,酯化率最高可达90.86%.     

非酸催化合成偏苯三酸三辛酯的研究

描述了偏苯三酸酐与2-乙基己醇合成增塑剂偏苯三酸三辛酯.通过实验,从钛酸四丁酯、铝酸钠、氧化亚锡等非酸性催化剂中选择了酯化催化性能良好的氧化亚锡作为催化剂,并探讨了催化剂氧化亚锡的用量、酸醇物质的量比、反应时问及催化荆氧化亚锡的重复使用对反应结果的影响.实验结果表明,氧化亚锡催化合成偏苯三酸三辛酯的最佳条件是:酸醇比为n(偏苯酸酐):n(2-乙基己醇)=1:4.5(摩尔比),催化剂用量为偏苯三酸酐质量的0.6%,反应时间为4 h,反应温度为220～238℃,催化剂氧化亚锡可以重复使用,酯化率可达99.9%.     

无溶剂体系中合成1,4-丁二醇二丙烯酸酯

以1,4-丁二醇、丙烯酸为原料,对甲苯磺酸为催化剂,对苯二酚为阻聚剂,采用真空无溶剂直接酯化法合成1,4-丁二醇二丙烯酸酯。探讨了催化剂、反应时间和温度以及酸醇比(丙烯酸与1,4-丁二醇摩尔比)对酯化反应的影响。结果表明,最佳的酯化反应条件为:丙烯酸/1,4-丁二醇为3,催化剂用量(占原料总质量,%)为0.5%,阻聚剂质量分数(占原料总质量,%)为0.25%,反应时间为8 h,反应温度为75⁸0℃。在此条件下,产物为淡黄色透明油状液体,收率可达80%。     

无溶剂体系中合成1,4-丁二醇二丙烯酸酯

以1,4-丁二醇、丙烯酸为原料,对甲苯磺酸为催化剂,对苯二酚为阻聚剂,采用真空无溶剂直接酯化法合成1,4-丁二醇二丙烯酸酯。探讨了催化剂、反应时间和温度以及酸醇比(丙烯酸与1,4-丁二醇摩尔比)对酯化反应的影响。结果表明,最佳的酯化反应条件为:丙烯酸/1,4-丁二醇为3,催化剂用量(占原料总质量,%)为0.5%,阻聚剂质量分数(占原料总质量,%)为0.25%,反应时间为8 h,反应温度为75~80℃。在此条件下,产物为淡黄色透明油状液体,收率可达80%。     

非酸催化合成偏苯三酸三辛酯的研究

本文主要描述了偏苯三酸酐与2-乙基己醇合成增塑剂偏苯三酸三辛酯。通过实验，从钛酸四丁酯、铝酸钠、氧化亚锡等非酸性催化剂中选择了酯化催化性能良好的氧化亚锡作为催化剂，并探讨了催化剂氧化亚锡的用量、酸醇物质的量比、反应时间及催化剂氧化亚锡的重复使用对反应结果的影响。实验结果表明，氧化亚锡催化合成偏苯三酸三辛酯的最佳条件为：酸醇比为n（偏苯酸酐）：n（2-乙基己醇）=1：4．5（摩尔比），催化剂用量为偏苯三酸酐质量的0．6％，反应时间为4小时，反应温度为220～238℃，催化剂氧化亚锡可以重复使用，酯化率可达99.9％。     

丁二酸二异丙酯的树脂催化合成研究

本文阐述了用离子交换树脂替代无机酸、有机酸催化剂,催化合成1,4-二酮吡咯并吡咯类高档有机颜料的关键中间体丁二酸二异丙酯的方法。主要考察了不同类型树脂催化剂、催化剂用量、催化剂重复使用次数、异丙醇用量以及脱水剂用量对酯化收率的影响。酯化收率可以达到97．5％。     

基于间苯三酚的磺化碳基固体酸催化剂的制备及其催化油酸甲酯的合成

采用间苯三酚与对苯二甲醛缩聚得到的树脂为碳前驱体,分别以1,4-二氧六环与去离子水为溶剂,以溶剂热和水热法、氯磺酸为磺化试剂制备两种磺化碳基固体酸催化剂。SEM、XPS和TGA等分析表明,以1,4-二氧六环为溶剂合成的TP-A-S催化剂为形貌规整、高酸密度、良好稳定性的球形,并表现出良好的催化性能。将其用于油酸与甲醇的酯化反应,最适宜的条件为:醇油物质的量比10∶1,催化剂用量占原料总质量的2.0%,反应温度70℃,反应时间4h,油酸最高转化率达98.3%。且催化剂循环使用5次后,油酸转化率仍达84.4%。将制备的TP-A-S催化剂用于长链游离脂肪酸与甲醇的酯化反应,转化率高于90%,表现出良好的催化效果。     

漆酚铁锡聚合物催化剂的合成及应用

对漆酚铁锡聚合物进行了红外光谱分析 ,研究了漆酚铁锡聚合物作为固体酸催化剂催化酯化等反应的催化性能 ,并探讨了催化反应的可能反应机理。结果表明 ,在漆酚铁锡聚合物中存在M -O(Fe -O、Sn -O)键 ,催化活性中心是Mn + (Fe3 + 、Sn4+ ) ,漆酚铁锡聚合物是催化合成醋酸正丁酯、丙烯酸正丁酯、乙二醇单乙醚醋酸酯和环已酮缩乙二醇等酯和缩酮的良好催化剂 ,该催化剂能被多次重复使用 ,具有稳定的选择性 ,且催化活性能够再生。     

高分子金属配合物催化酯化反应

1 前言许多有机锡化合物都可作为酯化反应催化剂,其中催化活性较好的有草酸亚锡等亚锡有机酸盐类催化剂,它们较硫酸催化剂具有不易引起副反应、不腐蚀设备、产品热稳定性好等优点,但由于它们属于均相催化酯化反应,反应后催化剂回收和重复使用都很困难,而且产品体积电阻率降低,从而影响了它们的广泛应用。本文叙述了具有催化酯化活性的高分子金属配合物交联聚苯乙烯亚胺二乙酸-锡(Ⅱ)的制备方,     

Sapindaceae,cyanolipids, and bugs

Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.     

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.     

2008～2009年世界塑料工业进展

收集了2008年7月～2009年6月世界塑料工业的相关资料,介绍了2008～2009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、环氧树脂、不饱和聚酯树脂)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。     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

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.