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微胶囊红磷膨胀型阻燃剂的制备及应用 总被引:2,自引:0,他引:2
制备了微胶囊红磷/季戊四醇/三聚氰胺膨胀型阻燃剂(IFR)。采用吸湿性、抗氧化性、SEM、TG等测试方法对阻燃剂进行了表征。结果表明:微胶囊红磷的吸湿性减小、抗氧化性增强;TG分析显示,微胶囊红磷在385~422℃、470~553℃有两个失重阶段;600℃时,未包覆红磷残重仅为6%,而微胶囊包覆红磷的残重为12%;微胶囊红磷膨胀型阻燃剂的最佳组成为:微胶囊红磷:季戊四醇:三聚氰胺=4.00:0.75:2.00(摩尔比);500℃下,IFR残重高达65.06%;当IFR添加量为30%时,阻燃环氧树脂的氧指数从未添加IFR时的19.0%提高到26.3%。 相似文献
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微胶囊化红磷阻燃剂的研制及应用 总被引:2,自引:0,他引:2
论述了红磷包覆的必要性及包覆方法。分别采用酚醛树脂、脲醋树脂对红磷进行微胶囊化,检测了红磷包覆前后PH3的释放量,研究微胶囊化红磷对MC-尼龙的阻燃性能。 相似文献
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为了实现红磷的纳微化以及表面有机无机双层包覆,解决红磷保存时吸湿和释放有毒气体以及在高分子基材中的分散不均匀性问题,本研究借助易于工业化的球磨技术,制备出纳微化的红磷粒子,再分别利用二氧化硅为无机层,三聚氰胺氰尿酸盐为有机层,实现红磷的有机/无机双层包覆化。借助纳米粒度仪、扫描电镜和热重分析仪等表征手段,研究得出:双层包覆微胶囊红磷24h吸湿增重率仅0. 28%,磷化氢释放量控制在2×10~(-6),红磷保存性改善。将双层包覆红磷作为阻燃剂,物理共混于环氧树脂,发现添加16%含量时,极限氧指数最高为28. 2%;红磷与包覆层之间构成磷氮硅协效作用,属于凝聚相、气相双重阻燃,形成蓬松、封闭外层的炭层,起阻隔作用,增大了阻燃效率。这项研究可望为新型红磷阻燃剂的研究提供一定的理论借鉴意义。 相似文献
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《山东化工》2021,(6)
为了实现红磷的纳微化以及表面有机无机双层包覆,解决红磷保存时吸湿和释放有毒气体以及在高分子基材中的分散不均匀性问题,本研究借助易于工业化的球磨技术,制备出纳微化的红磷粒子,再分别利用二氧化硅为无机层,三聚氰胺氰尿酸盐为有机层,实现红磷的有机/无机双层包覆化。借助纳米粒度仪、扫描电镜和热重分析仪等表征手段,研究得出:双层包覆微胶囊红磷24h吸湿增重率仅0. 28%,磷化氢释放量控制在2×10-6,红磷保存性改善。将双层包覆红磷作为阻燃剂,物理共混于环氧树脂,发现添加16%含量时,极限氧指数最高为28. 2%;红磷与包覆层之间构成磷氮硅协效作用,属于凝聚相、气相双重阻燃,形成蓬松、封闭外层的炭层,起阻隔作用,增大了阻燃效率。这项研究可望为新型红磷阻燃剂的研究提供一定的理论借鉴意义。 相似文献
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M. S. J. Simmonds W. M. Blaney F. Delle Monache M. Marquina Mac-Quhae G. B. Marini Bettolo 《Journal of chemical ecology》1985,11(12):1593-1599
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. 相似文献
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Cheng-Le Zhao Shane Porzio Alan Smith Haiyan Ge H. T. Davis L. E. Scriven 《Journal of Coatings Technology and Research》2006,3(2):109-115
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. 相似文献
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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. 相似文献
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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. 相似文献
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Peter A. Edwards Grant Striemer Dean C. Webster 《Journal of Coatings Technology and Research》2005,2(7):517-527
Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins.
Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol.
The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and
cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on
the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to
determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model
amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate
functional group is more reactive than a glycidyl ether group.
Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago,
IL. 相似文献