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1.
采用极限氧指数、拉伸试验机和扫描电子显微镜对可膨胀石墨(EG)和甲基膦酸二甲酯(DMMP)复配阻燃聚氨酯酰亚胺泡沫塑料(PUI)的阻燃性能、表面炭层形貌及力学性能等进行了研究。结果表明,阻燃剂添加量相同时,复配阻燃体系的极限氧指数值高于EG单独阻燃PUI,PUI/EG/DMMP体系的极限氧指数值由18.6 %提高至33.4 %;EG/DMMP的复配,减少了对泡孔结构的破坏,PUI/EG/DMMP燃烧后能生成更加连续和致密的炭层;阻燃剂添加量相同时,与EG单独阻燃PUI相比,EG/DMMP复配减少了对压缩性能的损害。  相似文献   

2.
《塑料科技》2016,(10):66-70
将可膨胀石墨(EG)与聚磷酸铵(APP)复配并添加至聚苯乙烯(PS)基体中,制备了PS/EG/APP阻燃复合材料。通过极限氧指数(LOI)、水平垂直燃烧(UL 94)测试,以及热重分析(TG)和扫描电镜分析(SEM)对PS/EG/APP阻燃复合材料的阻燃性能和热稳定性进行了检测,并优化了该材料配方。结果表明:复合阻燃剂EG/APP的加入,使得体系的LOI值与热稳定性均明显提高。其中当复合阻燃剂EG/APP的添加量为30 phr,且质量比为3:1时,阻燃体系的LOI值可达到31.8%,而单独添加同量EG或APP的阻燃体系,其LOI值仅为29%和20.8%,这说明EG与APP之间存在协同效应。  相似文献   

3.
以聚磷酸铵/膨胀石墨(APP/EG)为阻燃剂,制备了高阻燃的聚异氰酸酯-聚氨酯(PIR-PU)泡沫材料。采用极限氧指数(LOI)测试、红外光谱分析(IR)、热重分析(TGA)等方法对所制备PIR-PU泡沫材料的燃烧及热降解行为进行了研究。结果表明:APP与EG存在着良好的协同阻燃作用,APP/EG的添加可有效提高PIR-PU泡沫材料的LOI值,其中当APP/EG用量为25份、其配比为3/7时,PIR-PU泡沫材料具有最佳阻燃性能,材料的LOI值可达35.4%。APP与EG的复配使用,使PIR-PU泡沫材料的炭层较单独使用APP或EG时更为致密,有效提高了材料的热分解温度,降低了热降解速率,进而改善了材料的阻燃性能。  相似文献   

4.
选用聚磷酸铵(APP)与二乙基次膦酸铝(ADP)复配用于木塑复合材料(WPC)的阻燃并研究了材料的阻燃性能。结果表明,纯WPC的氧指数(LOI)值为23.5%,当单独添加19%(wt)的APP时,材料通过了垂直燃烧测试UL-94 V-0级,LOI值为28.9%。当APP与ADP以质量比为6∶1复配,阻燃剂总添加量仅为15%(wt)时,材料通过了UL-94 V-0级,LOI值达到了28.7%,表明ADP/APP体系对WPC具有很好的协同阻燃效应。力学性能测试表明,APP/ADP体系的加入对材料的力学性能影响较小。热重分析测试表明,APP/ADP体系促进了材料的初期热降解,但提高了材料的成炭性能。锥形量热测试及扫描电镜对残炭的测试表明,APP/ADP体系的加入使得材料在燃烧过程中形成了膨胀、连续的炭层,很好地抑制了材料的燃烧,使得材料的热释放速率、总热释放量显著降低。  相似文献   

5.
《塑料》2015,(4)
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。  相似文献   

6.
膨胀石墨在聚乙烯中阻燃协效作用的研究   总被引:8,自引:0,他引:8  
以膨胀石墨(EG)与聚磷酸铵(APP)复配组成膨胀型阻燃剂,应用于高密度聚乙烯(PE-HD)中。热分析表明APP/FG的添加使得PE-HD材料的热稳定性增强,降解过程变缓,剩炭率增加。氧指数(LOI)结果表明APP/EG具有良好的阻燃协同作用。扫描电镜(SEM)显示APP/EG的加入可使得PE-HD样品生成连续致密的炭层。同时力学性能研究表明APP/EG对材料的力学性能的影响比其它膨胀型阻燃剂要小。  相似文献   

7.
以三聚氰胺和甲醛溶液为原料,合成了三羟甲基三聚氰胺(TMM),并将其与聚磷酸铵(APP)作为复配阻燃剂,采用聚酰亚胺预聚法制备了阻燃聚氨酯–酰亚胺(PUI)泡沫塑料。分析了TMM/APP对PUI泡沫塑料极限氧指数(LOI)、烟密度等级和炭层形貌的影响。结果表明,合成的TMM有较高的残炭率和最大热失重温度;随着TMM/APP用量的增加,泡沫的LOI增大,烟密度降低,当TMM与APP配比为1∶3时LOI最高可达31.2%;TMM能改善泡沫炭层多孔的缺点。  相似文献   

8.
制备了可膨胀石墨(EG)和N,N-[双(2-羟乙基)氨甲基]磷酸二乙酯(BHAPE)单独添加及复配使用阻燃的硬质聚氨酯泡沫塑料(RPUF),通过万能拉伸试验机、组合冲击试验机、氧指数仪、综合热分析仪、锥形量热仪和扫描电镜(SEM)等测试,对力学性能、阻燃性、热稳定性、燃烧性能及炭层形貌等进行了分析。结果表明,BHAPE的添加能够改善RPUF的比冲击强度,减少EG对体系力学性能的损害;氧指数(LOI)的实际值明显高于计算值,复配组分的LOI由20.3%提高到29.2%,EG/BHAPE具有显著的协同效应;EG/BHAPE复配使阻燃体系的初始分解温度、最大热解速率、热释放速率、总热及总烟释放量降低,残炭率提高,燃烧后形成厚且致密的炭层。  相似文献   

9.
采用一步发泡法制备出聚氨酯泡沫(PUF),将精制碱木质素与聚磷酸铵(APP)按不同比例组成膨胀阻燃剂(IFR)并添加到PUF中,制得碱木质素/聚磷酸铵膨胀阻燃聚氨酯泡沫(PUF/IFR)。通过极限氧指数(LOI)测试、热重分析(TG)、扫描电镜(SEM)考察了PUF/IFR材料的阻燃性能、热降解行为、成炭性能及残炭微观形貌。结果表明:当碱木质素与APP的复配比为1:6、IFR添加量为30%时,PUF/IFR的LOI值达到26.3%。IFR的加入形成了连续致密的炭层附着在材料表面,降低了材料的热降解速率,提高了残炭率,从而改善了材料的热稳定性和阻燃性能。  相似文献   

10.
《粘接》2017,(4)
以蓖麻油为基础多元醇,聚磷酸铵(APP)与次磷酸铝(AHP)复配协同聚氨酯阻燃体系,制备了阻燃聚氨酯密封胶(FRPUS)。研究了APP/AHP阻燃体系对FRPUS阻燃性能、热稳定性能的影响。结果表明,APP与AHP的质量比为5:1,添加量为50%时,FRPUS的极限氧指数(LOI)值达到35.1%,较纯PUS提高74.6%;TGA和热降解动力学表明APP/AHP提高了阻燃体系的热稳定性。  相似文献   

11.
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   

12.
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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Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.  相似文献   

18.
收集了2007年7月~2008年6月世界塑料工业的相关资料,介绍了2007~2008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、不饱和聚酯树脂、环氧树脂)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.  相似文献   

19.
收集了2005年7月~2006年6月国外塑料工业的相关资料,介绍了2005—2006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生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。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(聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、通用热固性树脂(酚醛、聚氨酯、不饱和树脂、环氧树脂)、特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮)的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。  相似文献   

20.
Inorganic/organic hybrid materials have considerable promise and are beginning to become a major area of research for many coating usages, including abrasion and corrosion resistance. Our primary approach is to prepare the inorganic phase in situ within the film formation process of the organic phase. The inorganic phase is introduced via sol-gel chemistry into a thermosetting organic phase. By this method, the size, periodicity, spatial positioning, and density of the inorganic phase can be controlled. An important aspect of the inorganic/organic hybrid materials is the coupling agent. The initial task of the coupling agent is to provide uniform mixing of the oligomeric organic phase with the sol-gel precursors, which are otherwise immiscible. UV-curable inorganic/organic hybrid systems have the advantages of a rapid cure and the ability to be used on heat sensitive substrates such as molded plastics. Also, it is possible to have better control of the growth of the inorganic phase using UV curing. It is our ultimate goal to completely separate the curing of inorganic and organic phases to gain complete control over the morphology, and hence optimization of “all” the coating properties. Thus far, it has been found that concomitant UV curing of the inorganic and organic phases using titanium sol-gel precursors afforded nanocomposite coatings which completely block the substrate from UV light while maintaining a transparent to visible light. Also, it has been found that the morphology of the inorganic phase is highly dependent on the concentration and reactivity of the coupling agent. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004, in Chicago, IL.  相似文献   

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