结晶型氢氧化镁阻燃剂制备工艺研究

以卤片和氨水为原料,采用控制结晶工艺制备阻燃级氢氧化镁,研究了反应温度、反应时间对氢氧化镁合成的影响.并在间歇合成氢氧化镁条件实验的基础上进行了连续合成实验和水热改性实验,结果表明连续控制结晶合成的氢氧化镁产物的结晶形貌及性能明显优于间歇结晶产物.     

氢氧化镁阻燃剂制备研究进展

氢氧化镁作为一种新型无机阻燃材料,具有热稳定性好、分解温度高等特点,且受热分解后无腐蚀性和有毒物质产生,其应用前景较为广阔。介绍了氢氧化镁阻燃剂的阻燃机理及特点。重点阐述了近年来氢氧化镁阻燃剂的制备方法,并对其存在的问题和发展方向进行了讨论。氢氧化镁阻燃剂的制备方法主要有固相法、气相法和液相法。固相法制备阻燃型氢氧化镁较为简单,但不易控制产品的粒径、形貌和分散性能。气相法制备氢氧化镁阻燃剂,采用氨气作为沉淀剂,制备工艺不易控制,而且氨气易于扩散污染环境。液相法制备氢氧化镁是最常用的方法,通过控制原料浓度、反应温度等条件,可以获得形貌和尺寸较好的氢氧化镁,也可扩大生产。     

氢氧化镁阻燃剂制备及性能研究

以氯化镁和氨水为原料,采用一步法制备氢氧化镁阻燃剂。考察了原料配比、反应温度、反应时间、搅拌转速对氢氧化镁产率、纯度及阻燃率的影响。利用X射线衍射仪(XRD)、傅里叶变换红外光谱仪(FT-IR)、综合热分析仪(TG-DSC)对制得的样品进行表征。通过单因素实验和正交实验得出优化工艺条件:原料配比(氨水与氯化镁物质的量比)为4∶1,反应温度为35℃,反应时间为60 min,搅拌转速为250 r/min。在此条件下氢氧化镁的产率为92.87%、纯度为96.89%、阻燃率为57.83%。     

轻烧粉氨气法制备氢氧化镁阻燃剂的研究

以除硫酸根后的轻烧粉精制液为原料,氨气为沉淀剂,在无表面活性剂条件下制备阻燃剂型氢氧化镁。采用X射线衍射仪（XRD）、扫描电镜（SEM）和激光粒度仪对产品进行表征。实验研究了通氨速率、反应温度对氢氧化镁产品形貌和粒度的影响,在较优的反应温度和通氨速率条件下考察了纯晶种加入量对产品的影响。实验结果表明,在纯晶种加入量为3%（质量分数）、氨气流量为300 mL/min、沉镁温度为90 ℃为制备阻燃剂型氢氧化镁的最佳条件,在此条件下产品的粒径D50=1.2 μm,比表面积（BET）为6.3 m2/g,转化率达到81.2%。     

海水淡化浓盐水制备复合阻燃材料研究

以海水淡化后废弃的浓盐水为原料,以氢氧化钠为沉淀剂,通过直接沉淀法制备复合阻燃材料,其主要成分为氢氧化镁和氢氧化钙。采用化学分析法和原子吸收分光光度法对浓海水中的离子含量进行定量分析;通过单因素实验考察了反应温度、反应时间、陈化时间对氢氧化镁和氢氧化钙沉降率的影响确定了最佳反应条件,并利用正交实验优化了工艺条件,对复合材料进行X射线衍射(XRD)分析、红外光谱(IR)分析、热重(TG)分析、差式扫描量热(DSC)分析、扫描电镜(SEM)分析。结果表明:在反应温度为40℃、反应时间为2.5 h、陈化时间为3.0 h条件下,氢氧化镁和氢氧化钙沉降率最大,分别为99.70%和91.99%;通过扫描电镜观察复合材料为片状形貌;通过热重分析和X射线衍射分析表明复合材料的主要成分为氢氧化镁和氢氧化钙。通过对复合材料进行一系列表征以及成分的深入研究,表明利用海水淡化废弃浓盐水可以制备出一种绿色环保的复合阻燃材料。     

注塑级低烟无卤阻燃木塑复合材料的制备与性能研究

在制备注塑级木塑复合材料(WPC)的基础上,采用磷系/氢氧化镁阻燃体系对WPC进行阻燃改性。通过物理性能对比、阻燃性能测试、炭层表面形态分析、热失重分析以及烟密度测试等对所制备WPC进行表征。结果表明:当磷系/氢氧化镁阻燃体系的用量为30%时,其阻燃等级能达到UL94 V-0级(1.5 mm),且其他性能保持较好;炭层表面的致密性及残炭率一定程度上决定WPC的阻燃性能;相对于溴-锑阻燃WPC,用磷系/氢氧化镁阻燃体系所制备的WPC属于低烟无卤阻燃复合材料。     

液相化学法制备氢氧化镁阻燃剂的技术研究

氢氧化镁作为一种绿色环保、安全无毒的无机阻燃剂用于高分子材料的阻燃具有阻燃、填充、消烟的三大功效。常规方法制备的氢氧化镁其阻燃性能并不理想。采用特殊的制备工艺得到的氢氧化镁其粒径、形貌、分散性能得到了有效控制,用于高分子材料的阻燃其阻燃效果更好。简要介绍了无机氢氧化镁阻燃剂的特点和阻燃机理,重点阐述了直接沉淀法、反向沉淀法、水热法及沉淀-共沸法等液相化学法制备氢氧化镁的研究进展,并对其发展方向进行了展望。     

氢氧化镁/氢氧化铝/三聚氰胺磷酸盐协效无卤膨胀型阻燃硅橡胶的制备与性能研究

以碱催化平衡聚合法制备的α,ω-二羟基聚二甲基硅氧烷为基胶,制备氢氧化镁/氢氧化铝/三聚氰胺磷酸盐(MP)协效无卤膨胀型阻燃硅橡胶,并对其结构和性能进行研究。结果表明:氢氧化镁/氢氧化铝/MP可产生阻燃协同作用,能够使复合硅橡胶的阻燃性能、热稳定性能和抑烟性能进一步增强。氢氧化镁/氢氧化铝/MP阻燃硅橡胶不仅具有优异的阻燃性能,还能保持良好的物理性能,当复合阻燃剂氢氧化镁/氢氧化铝/MP并用比为12/18/30时,复合硅橡胶的综合性能最佳。     

氢氧化镁阻燃环氧树脂热降解性能研究

用氢氧化镁制备了阻燃环氧树脂复合材料,用极限氧指数(LOI)、烟密度等级(SDR)来表征其阻燃消烟性能,用热重仪和热重-质谱联用仪分析了氢氧化镁阻燃环氧树脂体系的热稳定性和热降解过程,并探讨了氢氧化镁阻燃环氧树脂的机理。结果表明:随着氢氧化镁用量的增加,复合材料的LOI不断提高,当氢氧化镁用量为47.37%时,环氧树脂/氢氧化镁阻燃体系的LOI达到27.5%,烟密度降至61.73%;氢氧化镁的加入使复合材料的最大热失重速率提高,促进了复合材料的迅速分解,使分解的温度区间变窄,降低了分解过程中二氧化碳、可燃性小分子、苯类和苯酚类物质的释放量。     

阻燃EPDM/PP TPV的研究

研究制备工艺和阻燃剂用量对EPDM／PP阻燃热塑性硫化胶（TPV）性能的影响。结果表明，采用十溴联苯醚（FR-10）／三氧化二锑并用阻燃体系，阻燃剂在动态硫化前加入，EPDM／PPTPV的阻燃性能较好，但物理性能稍差，阻燃剂用量较大时，EPDM／PPTPV的阻燃性能较好，但拉伸强度减小；采用FR—10／三氧化二锑／氢氧化镁并用阻燃体系，氢氧化镁在动态硫化前加入，EPDM／PPTPV的阻燃性能稍好，物理性能和挤出外观质量略差，氢氧化镁用量对EPDM／PPTPV的阻燃性能影响不大。采用FR—1O／三氧化二锑／氢氧化镁并用阻燃体系，氢氧化镁在动态硫化前加入，可制备低硬度阻燃低发烟EPDM／PP TPV。     

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.     

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.     

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.     

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。