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1.
复配改性黏土/丁腈橡胶纳米复合材料的结构及性能   总被引:1,自引:0,他引:1  
用不同阴离子表面活性剂十二烷基磺酸钠(SDS)和十二烷基苯磺酸钠(SDBS)与阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)复配改性无机黏土,制备了有机改性黏土/丁腈橡胶(NBR)纳米复合材料,并表征了有机黏土与纳米复合材料,考察了不同表面活性剂及配比对纳米复合材料物理机械性能的影响。结果表明,CTAB/SDS复配改性黏土/NBR纳米复合材料的层间距比CTAB改性黏土/NBR纳米复合材料增加了1.15 nm,具有更多的插层结构,橡胶基体中黏土颗粒分布细致、均匀,且黏土片层间无聚集体存在;CTAB/SDS复配改性黏土/NBR纳米复合材料的物理机械性能优于CTAB/SDBS复配改性黏土/NBR纳米复合材料及CTAB改性黏土/NBR纳米复合材料,且当CTAB/SDS(质量比)为4∶2时,纳米复合材料的拉伸强度、撕裂强度及扯断伸长率出现最大值,其中,拉伸强度和撕裂强度较CTAB改性黏土/NBR纳米复合材料分别提高了62.7%和12.3%。  相似文献   

2.
采用十六烷基三甲基溴化铵(CTAB)和十八烷基三甲基溴化铵(STAB)分别对无机粘土进行有机改性,然后制备有机粘上/SBR纳米复合材料,研究不同季铵盐类改性剂对无机粘土的改性效果。结果表明:CTAB改性有机粘土与STAB改性有机粘土的片层间距分别从无机粘土的1.26nm增加到3.77nm和4.39nm;CTAB改性有机粘土的片层结构较稳定,而且在橡胶基体中的分散效果较好;所制备的有机粘土/SBR纳米复合材料的片层结构较多,力学性能较好。  相似文献   

3.
《塑料》2017,(5)
分别采用无机黏土(Clay)、十八烷基三甲基溴化铵(STAB)改性黏土(S-OC)以及十八烷基三甲基溴化铵(STAB)/十二烷基磺酸钠(SDS)复配改性黏土(SS-OC)填充聚乳酸(PLA)制得复合材料PLA/Clay、PLA/S-OC和PLA/SS-OC,通过拉伸性能测试和冲击性能测试,研究了黏土种类及含量对复合材料力学性能的影响。结果表明:PLA/SS-OC的力学性能(拉伸强度、断裂伸长率、冲击强度)均最优,随着SS-OC含量的增加,材料的力学性能先升高后下降,含量为2%时,性能最佳。通过X射线衍射(XRD)和扫描电子显微镜分析(SEM)发现,黏土改性后,晶层间距增大,在PLA基体中分散性提高,且SS-OC插层效果优于S-OC。  相似文献   

4.
采用CTAB/CPL(比例为3.0g∶1.0g)复配改性有机黏土制备NBRCNs,考察了复配改性有机黏土制备的NBRCNs的微观结构、力学性能和分散相态。实验结果表明,无机黏土经CTAB/CPL复配改性后,黏土晶层间距由起始1.25nm扩大至1.82nm,NBRCNs中黏土晶层间距进一步扩大为4.67nm,即橡胶大分子链进一步插层进入黏土片层中,制备得到插层型纳米复合材料。有机黏土用量为10份时,复配改性有机黏土制备的NBRCNs的各项力学性能最优,拉伸强度为5.16 MPa,撕裂强度为20.97kN/m,较纯NBR硫化胶的1.53MPa和8.77kN/m分别提高了237%和139%,且明显优于采用单一阳离子CTAB改性有机黏土制备的NBRCNs,充分显示了复配有机改性黏土的可行性和优越性。复配有机改性黏土制备的NBRCNs的微观分散相态优于单一阳离子改性有机黏土制备的NBRCNs。  相似文献   

5.
《弹性体》2016,(4)
以蒙脱土(MMT)为原料,通过选用阳离子表面活性剂十八烷基三甲基溴化铵(STAB)与阴离子表面活性剂十二烷基磺酸钠(SDS)对MMT进行复配改性,制得有机黏土(OC)/天然橡胶(NR)纳米复合材料(NRCNs)。考察了不同OC含量及阴阳离子表面活性剂配比对NRCNs力学性能以及微观结构的影响。结果表明,当MMT/STAB/SDS质量比为2.8/1/0.5时力学性能最佳,MMT层间距从1.24nm提高到4.8nm,NRCNs的层间距达到5.58nm;STAB/SDS复配改性比单一STAB改性效果好,NRCNs拉伸强度达到21.94 MPa,撕裂强度达到33.28kN/m,与纯胶相比分别提高了70%和69.2%;STAB取代了MMT层间的无机阳离子,SDS吸附了层间的负电荷使得插层结构增多,黏土均匀地分散在橡胶基体中。  相似文献   

6.
采用不同浓度的十六烷基三甲基溴化铵(CTAB)对凹凸棒石黏土(ATC)进行改性,对比了施加电场前后其电流变性能的变化规律,结果表明:改性凹凸棒石黏土在电场E作用下表现出Bingham流体特性,并且屈服应力τy与E0.4成正比;65℃是电流变性能突变的临界温度;通过介电性能的测试,发现CTAB对电流变响应的贡献较大。60 d后,改性凹凸棒石黏土的悬浮率仍可达到91%。  相似文献   

7.
采用十六烷基氯化吡啶(CPC)改性无机黏土(蒙脱土,MMT)并制备橡胶/黏土纳米复合材料,研究了有机黏土/丁腈橡胶纳米复合材料(NBRCNs)的结构、力学性能和微观相态。结果表明,CPC改性MMT所制备NBRCNs中有机黏土的片层间距5.10 nm要大于十六烷基三甲基溴化铵(CTAB)改性MMT的4.41 nm,表明其形成了更多的插层结构。当MMT与改性剂的质量比为2.5/1.0时,CPC改性MMT所制备NBRCNs的拉伸强度和撕裂强度分别为4.72 MPa和26.66 kN/m,较CTAB改性MMT的3.28 MPa和16.50 kN/m分别提高了44%和62%,且前者所制备NBRCNs的相态分散程度比后者更加细致均匀。将CPC改性MMT用于添加丁腈橡胶等极性橡胶的增强效果要优于添加丁苯橡胶等非极性橡胶。  相似文献   

8.
针对V上层系注聚前、后储层物性变化规律不明,不利于后续水驱提高采收率措施优选等问题,从储层岩石组分入手,对比分析了注聚前、后以及后续水驱等开发阶段的储层岩屑和黏土矿物成分含量、物性及储层物性变化,总结V上层系储层岩石特征及储层物性随开发阶段的变化规律。结果表明:聚驱前到后续水驱,水下分流河道及河口坝微相中绿泥石和伊蒙混层黏土矿物含量分别减少5%、9%,前缘席状砂微相绿泥石和伊蒙混层黏土矿物含量分别增加3%、3%;孔隙度减小0.95%、渗透率减小487.2×10-3μm2。  相似文献   

9.
采用长链脂肪族季铵盐改性有机粘土的方法,研究了烷基铵盐改性剂的碳链长度及配比对无机粘土(MMT)改性效果的影响。结果表明,同一改性剂配比下,由不同碳链长度的烷基铵盐改性剂改性MMT制备的丁腈橡胶/粘土纳米复合材料(NBRCNs)的微观结构、力学性能和分散相态不同,碳链长度适中的十二烷基三甲基溴化铵(CTAB)改性效果较好,碳链长度较长或较短都不利于MMT的改性。对于碳链长度较短的二十二烷基三甲基溴化铵(DTAB),当DTAB用量增加,粘土片层间距增大,力学性能提高。对于碳链长度较长的十八烷基三甲基溴化铵(STAB),STAB用量降低有助于扩大粘土片层间距和提高力学性能。  相似文献   

10.
以鄂尔多斯盆地宜川地区本溪组储层为例,通过岩石薄片观察、扫描电镜分析、X射线衍射实验分析、高压压汞实验等方法,对储层黏土矿物特征及潜在敏感性进行了分析。结果表明研究区砂岩中黏土矿物为伊利石、伊蒙混层、高岭石以及绿泥石,并以伊利石和伊蒙混层为主。浸泡实验发现黏土矿物遇水后会发生膨胀变形,并产生一定位移,从而对储层孔隙造成二次改造。因此,储层存在潜在的水敏和速敏性,在实际开发过程中应予以重视。  相似文献   

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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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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   

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