端胺基非异氰酸酯预聚体嵌段共聚聚醚型聚氨酯

用端胺基非异氰酸酯基聚氨酯预聚体与聚醚型聚氨酯预聚体嵌段共聚制备了改性聚醚型聚氨酯及其膜,分析了端胺基非异氰酸酯基聚氨酯预聚体,考查了聚醚型聚氨脂树脂成膜温度和预聚体NCO/ NH2配比对膜力学性能的影响,同时对比了聚氨酯材料的力学性能,采用差示扫描量热法（DSC）研究了相分离程度。结果表明,合成的端胺基非异氰酸酯基聚氨酯预聚体中成功地引入了氨基甲酸酯基团;最佳成膜温度为140 ℃;当预聚体NCO/NH2=1/0.9（摩尔比,下同）时膜的性能最好,拉伸强度为25.1 MPa,伸长100 %模量为5 MPa,;与普通聚氨酯相比,端胺基非异氰酸酯基聚氨酯预聚体嵌段的聚氨酯力学性能更高;DSC曲线显示其有2个不同的玻璃化转变温度,相分离明显。     

硅烷封端聚氨酯预聚体的合成研究

以聚醚二元醇、二异氰酸酯为主要原料合成了硅烷封端聚氨酯预聚体,使用合成得到的预聚体制备了硅烷封端聚氨酯密封胶并对其性能进行了考察。研究了二异氰酸酯类型,NCO/OH比例,反应温度,扩链剂类型及封端剂类型对硅烷封端聚氨酯(SPU)的影响。结果表明:使用两种混合二异氰酸酯,NCO∶OH=1.3～1.5,二甘醇作为扩链剂,γ-巯丙基三甲基硅烷(KH590)作为封端剂,反应温度85℃制备得到较理想的预聚体,可使硅烷封端聚氨酯密封胶拉伸强度达到1.78MPa,断裂伸长率达到490%。     

蓖麻油基聚氨酯配合物的研究

采用蓖麻油、甘油、TDI等为原料,合成出端-NCO的蓖麻油基聚氨酯PU预聚体.对预聚体中NCO的含量进行了测定,采用FT-IR对材料进行了定性分析,对树脂的固化工艺进行了探讨.结果表明,蓖麻油基PU预聚体的NCO质量分数在4.93%～5.25%时,树脂在-18～40 ℃能固化成膜,表干时间＜1 h.     

蓖麻油聚氨酯防水涂料的制备与性能研究

采用可再生的蓖麻油先分别与三羟甲基丙烷(TMP)、甘油反应,再与TDI反应,生成端基为-NCO的蓖麻油基聚氨酯预聚体.对其-NCO含量进行测试,并采用FT-IR对材料进行定性分析.并对固化后的涂膜附着力、力学性能、耐磨性和耐水性能进行了测试.结果表明:采用甘油醇解蓖麻油合成的聚氨酯性能较好,其最佳反应时间为3～4 h,反应后-NCO含量为4.90%～5.32%,体系在-10～40℃能固化成膜,且成膜物有较好的防水性能和力学性能.     

有机硅改性水性聚氨酯抗起毛起球剂

西安工程大学的张鹏等人以2,4-甲苯二异氰酸酯与聚乙二醇为原料,经预聚反应得到聚氨酯预聚体;再用γ-氨丙基三乙氧基硅烷封端改性,得到有机硅改性水性聚氨酯。当γ-氨丙基三乙氧基硅烷的用量为预聚体质量的5％时,改性聚氨酯的成膜性显著提高,膜的吸水性为17．2％。     

噁唑烷潜固化剂改性聚氨酯预聚体性能研究

以改性二苯基甲烷二异氰酸脂和聚醚多元醇等为原料,合成了噁唑烷潜固化剂改性聚氨酯预聚体,讨论了预聚体的异氰酸酯基含量及噁唑烷潜固化剂用量对固化性能的影响。结果表明,通过傅立叶变换红外光谱(FT-IR)对预聚体成膜的固化动态进行了分析表征,当NCO基质量分数为2.3%、噁唑烷潜固化剂质量分数为2.5%～3.5%时,预聚体固化时不产生发泡膨胀;固化20h后反应完全。     

湿气固化硅烷封端聚氨酯的结构与性能

利用3-异氰酸酯基丙基三甲氧基硅烷(KH901)与聚氧化丙烯二醇(PPG)端羟基的封端反应,合成了可湿气固化硅烷封端聚氨酯(STPU)。探讨了硬段含量、PPG分子量与树脂黏度、胶膜硬度和力学性能之间的关系,建立了STPU封端效率的表征方法。结果表明:提高PPG分子量会降低封端效率,增加树脂黏度,提高固化后胶膜的断裂伸长率;将过量PPG8000与异佛尔酮二异氰酸酯(IPDI)预聚,再与KH901反应,可制备高分子量STPU,但分子量分布较宽,黏度较大,固化后胶膜的断裂伸长率为140%;通过高分子量PPG18000与KH901的直接反应封端,合成的STPU黏度适中,胶膜断裂伸长率达240%,且合成步骤简单。     

硅烷改性聚氨酯的合成研究

以氢基硅烷偶联剂为基础，对以异氰酸酯基为端基的聚氨酯预聚体进行再封端．合成了一系列不同硅烷封端率的单组分温固化聚氨酯。测试结果表明：硅烷偶联剂成功接枝在聚氨酯预聚体上．产物的表干时间、粘接强度、耐湿热都得到很大改善，力学强度在一定封段率下保持较好．在聚氨酯密封胶、弹性体等领域有很好的应用前景。     

硅烷偶联剂改性湿固化聚氨酯热熔胶的性能研究

以3种硅烷偶联剂对湿固化聚氨酯热熔胶分别进行改性,制备了硅烷改性的湿固化聚氨酯(SPU)热熔胶,用热重分析、熔融黏度和粘接测试等方法对所合成材料进行表征。结果表明,采用KH550与异氰酸酯基的摩尔比值0.15进行改性,所制备的SPU热熔胶综合性能最佳,剪切强度比未改性的胶增加41.5%,固化物具有较好的热稳定性。     

新型端硅烷改性聚氨酯树脂合成

以3-异氰酸酯基丙基三乙氧基硅烷(IPTS)和聚醚多元醇(PPG)为主要原料,以二月桂酸二丁锡为催化剂,合成端硅烷改性聚氨酯预聚体,并在预聚体中添加贮存稳定剂A-171和催化剂辛酸亚锡制备单组分湿固化密封胶用端硅烷改性聚氨酯树脂。研究表明,相对于进口同类产品,该树脂黏度低,在18000 m Pa·s以下,具有优良的力学性能。     

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。