首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
制备了阻燃低气味的增强尼龙。分析了玻纤加入、尼龙类型和尼龙处理方式对尼龙力学性能的影响;并研究了阻燃剂种类和用量对玻纤增强尼龙性能的影响,最后研究了除味剂种类和用量对玻纤增强尼龙性能的影响。结果表明:短纤增强PA66具有较高的刚性和韧性;PA66经烘烤后所得玻纤增强PA66的刚性较高,而PA66不经烘烤所得玻纤增强PA66的韧性较高;红磷对玻纤增强的PA66阻燃效果好,且不对其力学性能产生影响;随着红磷阻燃母粒用量的增加,玻纤增强PA66的阻燃性能先变好后变差,在红磷用量为21份时达到最佳;凹凸棒石和红磷对玻纤增强PA66有优异的协同阻燃作用,当凹凸棒石用量为在4份时,达到最佳。SW-120和尼龙塑料除味剂同时使用,对玻纤增强PA66的气味有显著的改善。  相似文献   

2.
阻燃剂对玻纤增强尼龙66性能的影响   总被引:2,自引:2,他引:2  
比较和分析了不同类型阻燃剂对玻纤增强尼龙(PA)66性能的影响。结果表明,在PA常用阻燃剂卤化物,红磷和氮化物中,红磷是帛得具有良好力学性能,电性能的阻燃增强PA66的最佳阻燃剂:溴化物阻燃的玻纤增强PA66也具有良好的综合性能;氮化物需加入较多的用量才能获得同样的阻燃效果;采用氮-磷或溴-磷复合阻燃体系可提高阻燃效果,减少阻燃剂总用量,从而保持玻纤增强PA66较高的力学性能,使其有更优异的使用性能。  相似文献   

3.
氢氧化镁包覆红磷阻燃玻纤增强PA66的性能研究   总被引:1,自引:0,他引:1  
制备了氢氧化镁[Mg(OH)2]包覆红磷(Mg-en-P),并将其应用于玻纤(GF)增强PA66的阻燃。当Mg-en-P用量为30份时,其阻燃PA66/GF(质量比100/35)材料可达V-0级,氧指数(LOI)为36.5%,其值比商品化红磷母粒(Com-en-P)阻燃PA66/GF高出7.5%,且燃烧时间较短。Mg-en-P阻燃PA66/GF材料的弯曲强度及耐漏电起痕指数(CTI)值均高于Com-en-P阻燃PA66/GF材料,而冲击强度略有降低。Mg-en-P阻燃PA66/GF材料在较低温度下失重,表明Mg(OH)2分解生成的水有助于红磷生成强脱水的聚偏磷酸,起到阻燃作用。  相似文献   

4.
采用溴化聚苯乙烯(BPS)作为阻燃剂,短玻纤和玻璃微珠作为增强体系,与尼龙66(PA66)共混,经双螺杆挤出机挤出,制备了高表面质量、力学性能优良的阻燃增强PA66复合材料.研究结果表明,添加19份BPS后,PA66可以达到V-0级别的阻燃效果.使用0.8份硅酮润滑剂对PA66的表面质量有一定改善,并且对力学性能影响很小.将玻璃微珠与短玻纤复配,一定程度上可以改善PA66的表面质量,但玻璃微珠对PA66力学性能有不利影响,因此用量不能太大,控制在5份以内.  相似文献   

5.
聚磷酸三聚氰胺对玻纤增强PA66的膨胀阻燃作用   总被引:9,自引:2,他引:7  
采用自制的新型膨胀型阻燃剂——聚磷酸三聚氰胺(MPP)对玻纤增强PA66进行阻燃,以氧指数和垂直燃烧(UL94)评价了其阻燃作用;以热失重测定了材料的热分解性能;以扫描电镜观察了材料残炭的结构;并探讨了MPP阻燃玻纤增强PA66的阻燃机理。试验表明,单一MPP对玻纤增强PA66有良好的阻燃效果,当添加25%时,阻燃材料的氧指数为38,0%,达到UL94V-0级;MPP参与了玻纤增强PA66的降解过程,在材料表面形成了致密的隔热、隔氧的泡沫炭层。  相似文献   

6.
针对三聚氰胺氰尿酸盐(MCA)粉体对尼龙(PA)进行阻燃改性时,MCA分散性差,材料阻燃性能不稳定的问题,运用特殊的包覆工艺成功制得了PA基MCA母粒。将制得的MCA母粒及MCA粉体分别与PA6或PA66共混挤出,制得阻燃PA材料。对比分析了MCA母粒及MCA粉体阻燃PA6或PA66的垂直燃烧性能和力学性能。结果表明,与MCA粉体相比,MCA母粒可在MCA含量较低的情况下使厚度为0.8 mm及1.6 mm的阻燃PA6或PA66试样的垂直燃烧等级达到V–0级。MCA母粒及粉体对阻燃PA6的弯曲强度和PA66的拉伸强度影响很小,MCA母粒阻燃PA6的拉伸强度较粉体阻燃的高,而阻燃PA66的弯曲强度低;MCA母粒使阻燃PA的缺口冲击强度降低,而MCA粉体对PA的缺口冲击强度影响较小,当MCA含量较低时,MCA母粒阻燃PA的缺口冲击强度明显高于MCA粉体阻燃的PA。制备的MCA阻燃母粒对PA的阻燃效果不受黑色母料的影响,且具有较好的阻燃稳定性。  相似文献   

7.
通过双螺杆挤出机熔融共混制备玻纤增强尼龙66(PA66)材料,研究了环境湿度、吸水率、成核剂对玻纤增强PA66材料尺寸稳定性的影响。结果表明:环境湿度越高、时间越长,玻纤增强PA66材料尺寸变得越大,且在垂直流动方向上的材料尺寸变化大于流动方向上的;环境湿度越低达到相同吸水率的时间越长,吸湿溶胀作用越明显,玻纤增强PA66材料尺寸变化越大;随着成核剂含量增加,玻纤增强PA66材料尺寸稍微变小,成核剂用量为0.50份时达到最小值,再增加其用量材料尺寸基本不变化。  相似文献   

8.
PA66阻燃改性研究   总被引:3,自引:3,他引:3  
通过卤系、氮系、磷系等阻燃体系对尼龙(PA)66进行阻燃改性研究,开发出一种赤磷与无机阻燃剂共用的复配阻燃体系。结果表明,当加入 赤磷10份、无机阻燃剂10份、玻纤30份时,利用该阻燃体系阻燃的PA66,其燃烧性能达FV-0级,拉伸强度大于100MPa,缺口冲击强度大于9kJ/m^2,综合性能优良。  相似文献   

9.
采用蒙脱土和次膦酸盐阻燃剂复合,与玻璃纤维和聚酰胺66进行共混挤出,制得阻燃增强PA66复合材料,主要探讨蒙脱土对该复合体系的阻燃协效作用和机械性能的影响。结果发现:蒙脱土的加入可以协效次膦酸盐阻燃玻纤增强PA66复合材料,有效的增强次膦酸盐在玻纤增强PA66的阻燃效果,但同时也会引起复合材料的机械性能的变化,蒙脱土的加入显著的引起复合材料冲击性能的下降。蒙脱土的少量加入可以减少次膦酸盐阻燃剂的用量,达到同等级的阻燃效果和更加优异的力学性能。  相似文献   

10.
采用聚苯醚(PPE)与红磷母粒(MRP)复配阻燃,并使用玻璃纤维进行增强,制备了无卤阻燃玻纤增强尼龙46(PA46)复合材料。研究了不同配比PPE/MRP及其用量对阻燃玻纤增强PA46复合材料性能的影响。结果表明,当PPE/MRP质量分数为12%且质量比=1/1时,能够在添加较少量的MRP的情况下得到较好的阻燃效果,达到UL94 V-0级(1.6 mm)。热失重分析(TG)表明材料的残炭率与其阻燃性能有很好的对应关系;残炭率低的试样,其阻燃性能也低,只达到V-1级;而残炭率高的试样,阻燃性能可达到V-0级。随着PPE添加量的逐渐增加,玻纤增强阻燃PA46的各项力学性能都有不同程度的提高;当PPE和MRP质量分数均为6%时,玻纤增强阻燃PA46垂直燃烧后形成的炭层平整性和致密性都较好,炭层表面孔隙较少,起到较好的阻燃效果,试样的力学性能和热变形温度都达到最佳,起到了很好的协同效应。  相似文献   

11.
12.
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   

13.
14.
15.
16.
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   

17.
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   

18.
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   

19.
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   

20.
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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号