DOPO型无卤阻燃环氧树脂体系的性能研究

采用9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)和DOPO型含磷环氧树脂(DOPO–EP)对双酚A型EP进行阻燃改性,研究了不同磷含量下两种阻燃剂对EP的改性效果。结果表明,随磷含量增加,EP/DOPO与EP/DOPO–EP体系的玻璃化转变温度均降低,但EP/DOPO–EP体系的降幅较小;DOPO与DOPO–EP均能有效地提高EP的阻燃性能,但DOPO–EP的阻燃效果更佳;EP/DOPO–EP体系的综合力学性能高于EP/DOPO体系。当磷质量分数分别为2.5%和1.5%时,EP/DOPO与EP/DOPO–EP体系的垂直燃烧等级均达到UL 94 V–0级,极限氧指数分别为32%和33%。EP/DOPO体系在磷质量分数为2.5%时的残炭率(700℃)为12.27%,较纯EP提高了17.3%,但其拉伸性能、冲击性能和弯曲强度均大幅下降。而EP/DOPO–EP体系在磷质量分数为1.5%时的残炭率(700℃)为20.07%,较纯EP提高了91.9%,其断裂伸长率和弯曲强度分别为2.32%和92.69 MPa,较纯EP分别提高了13.73%和24.27%,拉伸强度和缺口冲击强度分别为35.34 MPa和1.85 kJ/m2,较纯EP仅下降了1.56%和1.07%,综合性能最佳。     

不同POSS对磷⁃硅协同阻燃环氧树脂性能的影响

将两种多面体低聚倍半硅氧烷(POSS)分别与9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)基有机磷阻燃剂(D-bp)复配,制备了磷-硅协同阻燃环氧树脂,并对其阻燃、热、力学和动态力学性能等进行分析.结果表明,在磷含量仅为0.25％(质量分数,下同)时,磷-硅协同阻燃环氧树脂就能达到UL 94 V-0级...     

磷改性酚醛树脂的制备与性能

通过DOPO(9,10–二氢–9–氧杂–10–磷杂菲–10–氧化物)和多聚甲醛反应制备了含磷单体ODOPM(9,10–二氢–9–氧杂–10–磷杂菲–10–羟甲基–10–氧化物),并用于制备磷改性酚醛树脂。通过差示扫描量热(DSC)仪测试体系DOPO的反应程度,通过红外光谱表征ODOPM的结构,通过热重分析测试改性酚醛树脂体系的热行为,通过极限氧指数和垂直燃烧法测试树脂体系的阻燃性能,通过扫描电子显微镜观察树脂燃烧后残炭的微观形貌,并采用万能试验机测试树脂样条的强度性能。实验结果表明:实验成果制备得到目标产品ODOPM,随着含磷单体ODOPM含量的提高,酚醛树脂的阻燃性能随着提高,酚醛树脂的残炭量也随着提高。酚醛树脂通过凝聚相阻燃机理起到阻燃作用。当磷改性酚醛树脂的ODOPM单体含量为15%时,树脂的LOI值可以达到32.4%,并通过V–0垂直燃烧测试,并且磷改性酚醛树脂保持较好的强度。     

酚氧基环磷腈阻燃环氧树脂的热解过程研究

用自制六氯环三磷腈通过亲核取代反应制备了六（酚氧基）环三磷腈（HPCP）,并将HPCP与环氧树脂（EP）以不同比例共混,固化成型,采用氧指数仪和热质联用仪对其热性能和降解机理进行分析。结果表明,在EP中加入HPCP可提高材料的热解残炭率;当添加10份HPCP时,阻燃EP的极限氧指数可达27.0 %;HPCP的阻燃机理是其所含的氮磷2种元素的协效作用与自缩合放出H2O分子2种阻燃机理的共同作用。     

环三磷腈阻燃剂研究进展

简述了环三磷腈阻燃剂的阻燃机理,重点介绍了六苯氧基环三磷腈、氨基环三磷腈、六对醛基环三磷腈、DOPO(9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物)羟甲基苯氧基环三磷腈及其他环三磷腈阻燃剂的研究进展,展望了环三磷腈阻燃剂的发展前景。     

基于磷杂菲基团阻燃环氧树脂的研究进展

综述了近些年来基于9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)及其衍生物为主的添加型阻燃剂和反应型阻燃固化剂(包括DOPO中P-H键与C=N、C=O、C=C之间的反应)应用于环氧树脂材料中的研究概况,总结了每种体系的性能特点与阻燃机理,并对未来基于磷杂菲基团阻燃环氧树脂的发展进行了展望。     

DOPO–肉桂酰胺阻燃剂制备及其在PLA中应用

以9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)、肉桂酰胺为原料合成了一种氮磷复合型阻燃剂(DOPO–CDE),通过傅立叶变换红外光谱、核磁共振氢谱对合成产物结构进行了鉴定,显示DOPO–CDE成功制备。研究了原料配比、反应温度、反应时间对阻燃剂产率的影响,发现在DOPO:肉桂酰胺物质的量之比为1.5∶1,反应温度140℃,反应时间10 h时,产率可达38.13%。此外,通过热重表征,发现合成阻燃剂比DOPO热稳定性有了明显提高。在聚乳酸(PLA)中添加质量分数5%的DOPO和质量分数5%的DOPO–CDE得到两种阻燃复合材料,并分别测试其极限氧指数(LOI)和拉伸性能。结果表明,添加DOPO和DOPO–CDE的PLA阻燃复合材料的LOI由PLA的20.1%分别提高到26.4%和27.4%;添加DOPO–CDE的PLA阻燃复合材料拉伸强度和断裂伸长率分别达到55.1 MPa和8.7%,比添加DOPO的复合材料分别提高了13.6%和123.1%。     

阻燃型TOTA–DOPO固化EP制备与性能研究

利用桐马酸酐为原料进行水解制得环氧固化交联性更高的桐油三酸(TOTA),再以不同物质的量比的9,10–二氢–9–氧–10–磷杂菲–10–氧化物(DOPO)和TOTA通过Michael加成反应制得TOTA–DOPO,红外光谱和核磁共振分析结果表明目标产物已成功合成;再将制得的阻燃固化剂TOTA–DOPO与E51环氧树脂(EP)固化后得到一系列刚性固化材料,并对其各项性能进行分析。研究结果表明,固化材料的拉伸强度随着DOPO加成反应量的增加逐渐降低,而其硬度、玻璃化转变温度、阻燃性能则随着DOPO加成反应量的增加逐渐增加;热重分析表明,制得的EP固化材料均具有良好的热稳定性,其热初始分解温度均在340℃以上。     

DOPO阻燃PLA/BF复合材料的制备与性能研究

以9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)为阻燃剂,制备了聚乳酸/竹纤维(PLA/BF)阻燃复合材料,并通过极限氧指数(LOI)测试、热重分析、力学性能测试和扫描电镜(SEM)分析等手段考察了阻燃剂DOPO对复合材料阻燃性能、热降解行为及力学性能的影响。结果表明:DOPO对PLA/BF复合材料具有良好的阻燃效果。其中当DOPO用量达到4%时,复合材料的LOI由DOPO添加前的22.5%增至29.5%,材料的阻燃性能得到明显提升;同时,复合材料的热稳定性也明显提高,其最大热分解温度由331℃升至357℃,DTG曲线面积明显减小。     

六苯氧基环三磷腈对PA6阻燃性能的影响

将六苯氧基环三磷腈(HPCP)作为阻燃剂,添加到聚酰胺6(PA6)中,并对其力学性能、热性能、阻燃性能进行表征分析。结果表明:HPCP对PA6有良好的阻燃效果,随着HPCP添加量的增加,极限氧指数(LOI)呈上升趋势,添加量为20%时,从纯PA6的26%提升到31%,垂直燃烧测试(UL 94)也达到V-0级,并有效地抑制了PA6的滴落。相比于纯PA6,峰值热释放速率值(PHRR)明显降低。热失重(TG)和残余物的扫描电镜(SEM)分析结果表明,HPCP促使PA6成炭,抑制其燃烧,达到阻燃效果。     

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.     

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.     

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。