水性聚氨酯的环氧共聚改性研究

采用环氧树脂(EP)对水性聚氨酯(WPU)进行改性,通过自乳化法合成了EP改性的WPU.探讨了EP的加入方式、用量以及亲水剂等因素对WPU乳液和涂膜性能的影响.结果表明交联反应显著提高了乳液膜的硬度及其耐水性、力学性能.用二羟甲基丁酸(DMBA)替代二羟甲基丙酸(DMPA)作亲水剂制备的改性WPU乳液,其乳液性能、涂膜的硬度及其耐水性能更佳.     

酮亚胺对水性聚氨酯性能的改进

用丙酮分别和乙二胺、己二胺反应制备酮亚胺,并以其作为潜伏性扩链剂改善水性聚氨酯(PU)的性能。研究了酮亚胺以不同方式、加量对水性PU漆膜的厚度、硬度、耐水性、耐酸性、热稳定性和机械性能的影响。结果表明,采用丙酮缩乙二胺扩链的水性PU乳液的漆膜的耐水性优于用丙酮缩己二胺和用水扩链的PU乳液的漆膜,且加入过量的酮亚胺扩链效果较好,但其热稳定性并没有得到明显提高。     

涂料用环氧改性水性聚氨酯

采用异佛尔酮二异氰酸酯(IPDI)、聚醚二醇(N-220)、二羟甲基丙酸(DMPA)、一缩二乙二醇(DEG)、三羟甲基丙烷(TMP)和环氧树脂E-51,制备出涂料用的环氧改性水性聚氨酯乳液。聚合乳液中尽量保留环氧基不开环,后加固化剂使之开环产生交联作用,以提高硬度、耐水性、耐溶剂等性能,并且该乳液有较好的贮存稳定性,可用作水性木器涂料。通过红外光谱、粒径分析仪、热质分析仪(TGA)和差示扫描量热法(DSC)等对乳液进行了表征。实验结果表明:当环氧树脂添加量为6%~10%,亲水扩链剂DMPA用量为4.5%,扩链剂乙二胺加入量为1.0%时,乳液外观及稳定性最好,漆膜的耐热、耐水、拉伸、硬度等性能都较优异,可以作为一种性能优异的涂料用水性聚氨酯树脂。     

开孔剂对聚氨酯高回弹泡沫的影响

将开孔剂OP–1、OP–2、OP–3分别应用于二苯基甲烷二异氰酸酯(MDI)体系聚氨酯高回弹泡沫配方中,对比了它们的开孔效果,考察了它们对MDI体系高回弹泡沫的泡孔结构、阻燃性和力学性能的影响。结果表明:在MDI体系配方中,OP–1的开孔效果最强,OP–3的开孔效果最弱;开孔剂用量越多泡沫开孔性越好,但阻燃性变差;此外,开孔剂可以改善泡沫的手感,但使泡沫的硬度和撕裂强度降低。     

成核剂对聚丙烯结晶形态和力学性能的影响

研究了聚丙烯(PP)／成核剂共混物的结晶形态及力学性能。结果表明：加入成核剂后，提高PP的结晶温度，加快了结晶速度，使PP球晶细化；成核剂用量在0—0．2份之间时，PP的冲击强度、拉伸强度、硬度、热变形温度均随成核剂用量的增加而提高。     

封闭型环氧嵌段聚氨酯阴极电泳漆的制备与性能研究

合成了以聚氨酯为主链环氧树脂嵌段改性的封闭型阴极电泳漆。先制得预聚体,接着用环氧树脂接枝到聚氨酯主链上,最后用甲乙酮肟对剩余的—NCO封端。利用DSC对漆膜测试,证明树脂经解封后玻璃化温度明显提高。环氧树脂的接枝使漆膜的硬度、厚度进一步优化。研究了溶剂、环氧树脂及亲水剂用量和助溶剂种类的变化对漆膜性能的影响。实验结果表明恰当的参数配比能使漆膜性能达到最佳。     

不同成膜物质配比和成膜助剂用量对漆膜性能的影响

寻找水性木器漆中聚氨酯分散体与丙烯酸乳液的最佳配比及其成膜助剂最合理用量,使漆膜的性能得到充分发挥。水性聚氨酯分散体与水性丙烯酸乳液配比为1∶3(质量比),成膜助剂用量为6.0%～6.5%(质量分数)时,水性木器漆漆膜硬度、抗粘连性、耐水性和耐醇性最理想。     

聚醚型阳离子水性聚氨酯的合成及性能研究

采用异佛尔酮二异氰酸酯(IPDI)、聚醚二元醇、亲水扩链剂和其他小分子多元醇反应合成阳离子水性聚氨酯乳液,讨论了不同异氰酸酯、扩链剂用量对阳离子水性聚氨酯乳液的状态、涂膜的耐水与机械性能的影响。结果表明,随异氰酸酯用量的增加,涂膜的强度及硬度逐渐提高,但涂膜的柔韧性降低、弹性下降;随N-甲基二乙醇胺(MDEA)用量的增加,涂膜的机械性能及耐水性降低;异氰酸酯的含量为47.3%、扩链剂MDEA的含量为4.3%时,乳液具有较好的贮存稳定性,且涂膜的断裂伸长率为1568%,48h吸水率为4%,具有较好的柔韧性及耐水性能。     

硅烷改性水性聚氨酯分散液的合成与性能研究

以二羟甲基丙酸(DMPA)为亲水单体,甲苯二异氰酸酯(TDI)、聚醚二元醇(N210)为原料,丁二醇为扩链剂,三乙胺(TEA)为中和剂合成水性聚氨酯.采用有机硅烷对水性聚氨酯进行改性,研究了有机硅烷、亲水单体的用量对改性水性聚氨酯外观稳定性及涂膜性能的影响.结果表明:适量的有机硅烷的引入可以有效改善水性聚氨酯的耐水性、附着力以及硬度.当硅烷加入量为0.6%,改性水性聚氨酯的吸水率为5.5%,为未改性水性聚氨酯膜吸水率的1/6.     

天然松香改性苯丙乳液的制备及其性能研究

以苯乙烯(St)、甲基丙烯酸甲酯(MMA)、丙烯酸-2-乙基己酯(2-EHA)、丙烯酸-2-羟基乙酯(HEA)和丙烯酸(AA)为反应单体,利用天然松香乳液作为改性剂,通过乳液聚合的方式制备了松香-苯丙复合乳液。研究了乳化剂用量、引发剂用量、松香乳液用量和单体配比对乳液性能的影响。并通过TGA、DLS、TEM对所制备的复合乳液进行了表征。结果表明:当乳化剂用量为单体质量的5%、引发剂用量为单体质量的0.8%、松香乳液用量为单体质量的30%、m(硬单体)∶m(软单体)=2.5∶1时,制得的乳液呈白色泛蓝光,粒径为131 nm。成膜后,漆膜光滑透明,硬度(1H)、耐水性(接触角97.05°)和附着力(1级)等性能良好。     

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.     

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。     

ICP-MS法测定地球化学样品中As、Cr、Ge、V等18种微量痕量元素的研究

建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。