卡拉胶包覆APP/MnO2增强水性环氧树脂阻燃抑烟性能

用反相乳液法，以卡拉胶（KC）为壳材，聚磷酸铵（APP）和二氧化锰（MnO2）为芯材，制备了KC包覆APP/MnO2阻燃剂（KC-FR）。通过FTIR、 XRD、 SEM和 EDS对KC-FR进行了表征。结果表明：卡拉胶已成功包覆APP和MnO2，合成的样品具有微胶囊结构。将KC-FR应用于水性环氧树脂（EP）中，考察KC、APP、MnO2 三者质量比对EP阻燃、抑烟性能的影响。用极限氧指数（LOI）、垂直燃烧（UL-94）和锥形量热（CCT）测试了涂层的阻燃、抑烟性能。结果发现，当KC/APP/MnO2的质量比为2∶1∶1，并且在EP中添加量为20%时，制备的阻燃涂层EP2的LOI达到29.1%，UL-94达到V-0级，表现出较好的阻燃性能。EP2相比于其它涂层热释放峰值（pHRR）、热释放总量（THR）和烟释放总量（TSP）最低，相比于EP0分别下降了42%、37%和46%，表现出较好的抑烟性能。另外，热重分析（TGA）测试结果显示EP2在800℃残炭量（W800）为33%，表明KC-FR具有促进EP成炭的功能。通过SEM对残炭表面分析发现，EP2表面炭层更加致密，这表明KC-FR对促进形成稳定并且致密的炭层起到至关重要的作用。     

烷基次膦酸盐在PET材料中的阻燃性能

以二乙基次膦酸铝(ADP)和二乙基次膦酸锌(ZDP)复配为阻燃剂制备了PET阻燃材料,通过极限氧指数测试(LOI)和垂直燃烧测试(UL-94)分析了材料的阻燃性能。通过热重分析测试(TGA)探讨了材料的热降解行为及其成炭性能。采用锥形量热测试(CONE)研究了材料的燃烧行为,并对其燃烧后残炭的形貌进行了表征。结果表明:用ADP和ZDP复配制备的PET阻燃材料能显著提高其阻燃性能。当阻燃剂含量为12%,即ADP与ZDP的质量配比为8∶4时,PET阻燃材料的LOI可达37.2%,且能通过UL-94 V-0级,此时材料的燃烧滴落物炭化程度高,燃烧时热释放速率低。     

磷氮阻燃剂的合成及其在环氧树脂中的应用

由亚磷酸、乙腈和苯膦酰二氯(PPDC)合成了一种添加型阻燃剂——苯膦酰二氨基双乙基四膦酸(PAEPA)。通过FTIR和ESI-MS对PAEPA的结构进行了表征。并将PAEPA混入环氧树脂(EP)中制备了阻燃环氧树脂,通过TGA、UL-94测试和LOI测试考察了用三乙烯四胺(TETA)固化的环氧树脂的阻燃性和热性能。结果表明,当w(P)=2.6%时,环氧热固性材料表现出优异的阻燃性能,并通过了UL94实验的V-0等级,LOI为29.8%。热重分析结果表明:800℃的残炭量为17.7%。SEM结果表明:EP/TETA体系中的PAEPA明显促进环氧树脂形成更致密、丰富的密封炭层,以提高燃烧过程中基体的阻燃性能。     

DOPO衍生物阻燃环氧树脂的制备与性能研究

通过3-氨基苯氧基邻苯二甲腈(3-APN)与9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)反应,合成腈基型含磷阻燃剂DOPO-ATR,将阻燃剂按一定比例与双酚A型E-51环氧树脂复合,制备阻燃环氧固化物。通过TG测试、LOI测试、垂直燃烧测试和锥形量热测试,探究DOPO-ATR对阻燃环氧固化物的热稳定性和阻燃性能的影响,同时探究DOPO-ATR的阻燃机理。结果表明:当DOPO-ATR的添加量为10%时,阻燃环氧树脂的LOI值最大为34.8%,与纯EP相比提升55.4%;UL-94等级为V-0级,热释放速率峰值最小为533.28 kW/m~2,与纯EP相比降低32%;总热释放量最小为58.98 MJ/m~2,与纯EP相比降低43%;总烟气释放量最小为35.0 m~2。同时,DOPO-ATR的加入能够提高EP的热稳定性和残炭率。通过阻燃机理可知,DOPO-ATR在气相和凝聚相中均表现阻燃效果。因此,DOPOATR对EP具有一定的阻燃效果,且阻燃剂含量为10%时,阻燃效果最好。     

PBT/TPU/DOPO-MA阻燃复合材料的制备及性能

通过使用9,10-二氢-9-氧杂-10-磷朵菲-10-氧化物（DOPO）和马来酸酐反应合成制备DOPO衍生物阻燃剂DOPO-MA，并且其结构使用傅里叶红外光谱分析（FTIR）和核磁共振氢谱分析（¹H NMR）技术进行表征。将阻燃剂与聚对苯二甲酸丁二醇酯（PBT）和热塑性聚氨酯（TPU）熔融共混以制备PBT/TPU/DOPO-MA阻燃复合材料。通过运用锥形量热、UL-94、极限氧指数（LOI）、热重分析（TGA）、差热分析（DSC）和力学测试，研究了阻燃剂对复合材料的性能影响。测试结果表明，PBT/TPU/DOPO-MA复合材料具有良好的阻燃性能，加入10％DOPO-MA后，LOI从23.2增加到31.6，可达到UL-94 V-1等级，热释放率峰值（PHRR）和最大成热辐射速率（MAHRE）值降低；热重分析测试结果表明，添加DOPO-MA可以使得阻燃复合材料的热稳定性有显著的提高，当加入10％DOPO-MA后，残炭量可从6.87增加到14.36。此外，随着DOPO-MA含量的增加，阻燃复合材料的结晶度可得到一定的提高。     

无卤阻燃PBT的阻燃性及热稳定性

研究了聚对苯二甲酸丁二醇酯(PBT)与无卤磷-氮复配型阻燃剂复合体系的阻燃性能,着重研究了UL-94垂直燃烧性能、LOI以及TGA。结果表明:该P-N复配阻燃剂可有效地帮助复合体系通过UL-94燃烧性能测试,提高LOI及复合体系的热稳定性。     

新型含磷阻燃剂的制备及在环氧树脂体系中的应用

本文以三氯氧磷、对羟基苯甲醛及DOPO为原料成功合成了一种新型含磷阻燃剂DOPO-TPPO,采用FTIR测试对其结构进行了表征。通过热重分析测试(TGA)研究了产物的热稳定性、热降解行为及成炭性能,表明该阻燃剂具有较好的热稳定性和成炭性能。将阻燃剂DOPO-TPPO添加到环氧树脂中,以二氨基二苯硫砜(DDS)为固化剂制备阻燃环氧树脂固化物,通过极限氧指数(LOI)和垂直燃烧(UL-94)测试研究了环氧树脂固化物的阻燃性能。结果表明:合成产物的起始热分解温度为195℃,在700℃时的残炭量为29%,当阻燃剂添加量(质量分数)为11.0%时,环氧树脂固化物能通过垂直燃烧UL-94 V-0级,氧指数高达32.0%,表明该物质对环氧树脂材料具有优异的阻燃性能。     

功能化磷酸钛对PC阻燃和力学性能的影响

成功制备了一种核-壳结构的磷酸钛阻燃剂(F-TiP),并通过熔融共混法将其添加到聚碳酸酯(PC)中。采用极限氧指数测试(LOI)、垂直燃烧试验(UL-94)、热重分析(TG)及拉伸测试等方法,分析了该复合材料的阻燃和力学性能。结果表明:核-壳结构磷酸钛阻燃剂的最优含量为6%,此时复合材料体系的LOI为32.7%,同时其达到了UL-94的V-0级别。由于F-TiP阻燃剂的存在,TG分析结果显示炭层成碳量增加,且SEM分析显示炭层结构更为致密,并发现磷酸钛核和功能化壳之间存在协同阻燃作用。在6%范围内,随阻燃剂F-TiP含量的增加,复合材料的拉伸强度上升,断裂伸长率下降。     

聚磷酸铵/可膨胀石墨阻燃环氧树脂的性能

将聚磷酸铵(APP)与可膨胀石墨(EG)进行复配后添加到环氧树脂(EP)中,以间苯二胺(PDA)为固化剂,制备阻燃环氧树脂固化物,通过极限氧指数(LOI)、垂直燃烧(UL-94)和热重分析(TGA)测试研究了材料的阻燃性能、热降解行为,通过锥形量热(CONE)测试研究了材料的燃烧行为,通过扫描电镜(SEM)研究了材料炭层的形貌,同时还研究了APP与EG的不同配比对EP材料阻燃性能的影响。结果表明:当APP与EG的质量比为3∶2、添加量为5%时,阻燃EP材料通过了UL-94 V-0级,LOI值达到了29.0%。TGA测试结果表明:阻燃剂APP及EG的加入明显地改变了材料的热降解行为,促进了环氧树脂材料的提前降解和成炭,降低了材料的热降解速率,材料在700℃时的残炭量由14.6%提高到了29.9%。CONE测试结果表明:阻燃剂的加入明显降低了材料的热释放速率(HRR)和总热释放量(THR)。SEM测试结果表明:阻燃材料燃烧后形成了致密均一的炭层,能很好地阻止氧气和热量进入到材料的内部,同时减少可燃气体的逸出,从而抑制了基体树脂的进一步降解和燃烧,提高了材料的阻燃性能。     

纳米Al_2O_3对含磷环氧树脂体系的性能影响

研究了以纳米Al_2O_3作为协同阻燃剂,对EP/DOPO和EP/HPCTP树脂固化物阻燃性能的影响。通过热重分析测试(TGA)、动态热机械分析测试(DMA)、氧指数测定(LOI)及垂直燃烧测试(UL-94)重点探讨了树脂固化物的耐热及阻燃性能。测试结果表明,含磷阻燃剂有助于提高环氧树脂固化物的阻燃性能,但会降低其玻璃化转变温度(Tg)。随着纳米Al_2O_3的加入,残炭率(800℃)、极限氧指数(LOI)得到进一步的提高,并且能够在一定程度上提升树脂固化物的玻璃化转变温度(Tg)和初始热裂解温度(T5%)。     

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.     

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.     

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.     

Novel polyurethane coating technology through glycidyl carbamate chemistry

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.