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1.
制备了反应性单体改性纳米CaCO3填充PP复合材料,研究了反应性单体丙烯酸(AA)和苯乙烯(St)在有、无过氧化二异丙苯(DCP)存在下改性纳米CaCO3填充PP复合材料的力学性能,并用扫描电子显微镜(SEM)研究了复合材料弯曲断面的形态。结果表明,PP/改性纳米CaCO3的力学性能优于PP/微米CaCO3的力学性能;在DCP存在下,AA、AA与St混合改性可使PP/纳米CaCO3的拉伸性能和弯曲性能提高,减小拉伸强度随CaCO3含量增加而下降的趋势;并可有效提高纳米CaCO3在基体中的分散性和界面粘结性。  相似文献   

2.
供水管用改性聚丙烯/纳米CaCO3复合材料的研究   总被引:2,自引:3,他引:2  
以改性聚丙烯(PP)为基体、纳米CaCO3为填料,采用直接分散法及两步混炼工艺制备了供水管用改性PP/纳米CaCO3复合材料。阐述了纳米CaCO3的表面处理、钛酸酯偶联剂含量、纳米CaCO3含量及不同混合工艺对纳米复合材料性能的影响。同时对改性PP/纳米CaCO3复合材料及其供水管材的制备工艺进行了分析讨论,确定了改性PP/纳米CaCO3复合材料的配方及其成型工艺参数,并与国内外相关产品的性能进行了比较。  相似文献   

3.
采用纳米级CaCO3改性PP,同时考察了POE(乙烯辛烯共聚物)对该改性体系力学性能的影响。结果表明采用纳米级CaCO3和POE改性PP能明显提高PP的力学性能,而且该复合材料在生产中具有实际应用价值。  相似文献   

4.
不同形态纳米级CaCO3改性PP研究   总被引:3,自引:0,他引:3  
研究了不同形态纳米级CaCO3改性PP复合材料的力学性能及其对PP球晶形态的影响。结果表明,纳米级CaCO3形态不同,复合材料力学性能不一样,立方形纳米级CaCO3有利于改善复合材料的冲击性能,而纤维状纳米级CaCO3则能明显改善材料的拉伸性能。纳米级CaCO3能使PP球晶明显的细化.并能促进β晶型的生成。  相似文献   

5.
杨守洁  杨奇 《广东化工》2012,39(15):40-41
纳米CaCO3用于聚丙烯(PP)的改性研究及成果已有很多报导,主要体现在纳米CaCOH/PP复合材料的力学性能、热学性能及结晶性能等方面。文章着重介绍改性纳米CaCO3/PP复合材料结晶性能的研究状况,为人们后续的相关研究工作提供有价值的线索和依据。  相似文献   

6.
固相法改性纳米碳酸钙对丁苯橡胶的补强作用   总被引:1,自引:0,他引:1  
研究了用带有酚醛结构的反应性有机改性剂对纳米碳酸钙进行固相改性得到的M—CaCO3填充丁苯橡胶(SBR)所得复合材料的力学性能、热稳定性能、微观形态和老化性能.并与丁苯橡胶/硬脂酸包覆型纳米碳酸钙(CCR)复合材料的性能进行比较。结果表明,M—CaCO3对SBR力学性能和热稳定性能的提高比CCR更显著,且M—CaCO3能改善SBR的老化性能。电镜观察表明,M—CaCO3在SBR中的分散性优于CCR.且界面结合形态得到了改善。M—CaCO3添加量为20~40份时。复合材料综合力学性能最好。  相似文献   

7.
丁杨柳  张广平 《塑料工业》2007,35(B06):177-179,191
利用反应性单体甲基丙烯酸(MA)接枝聚丙烯(PP)后,二步法制备了反应改性纳米CaCO3/PP复合材料。研究了复合材料的力学性能,并用扫描电子显微镜(SEM)观察了复合材料经液氮冷却脆断后断面的形态。结果表明,甲基丙烯酸接枝聚丙烯(MAPP)加入后与CaCO3反应使MAPP与纳米CaCO3微聚体之间产生离子键作用,使纳米/PP复合材料的力学性能得到大幅提升,对冲击性能的改善尤为明显。充分控制的MA反应量比单独依靠MAPP增容能够更为有效地提高纳米CaCO3的分散性和界面黏结性。  相似文献   

8.
研究了纳米CaCO3/EPO/PP复合材料的力学性能、熔体流变性能及纳米CaCO3粒子在PP基体中的分散状况。结果表明:弹性体EPO对PP有很好的增韧效果,当EPO用量为4份时,PP从脆性断裂转变成韧性断裂;当EPO用量为10份时,PP复合材料的室温和低温缺口冲击强度均有大幅度的提高。在EPO/PP复合材料中加入纳米CaCO3不仅可以显著提高复合材料的室温和低温缺口冲击强度,而且可显著提高复合材料的弯曲弹性模量和MFR,改善复合材料的加工流动性能;纳米CaCO3粒子在PP中达到了纳米级分散。  相似文献   

9.
CaCO3/CPE/PP三元复合材料的性能研究   总被引:1,自引:0,他引:1  
分别研究了CPE和SBS对聚丙烯性能的影响,CPE使PP的熔融指数略有下降,CPE含量为10%时,CPE/PP的冲击和拉伸强度分别比纯聚丙烯提高了108%和12%;进一步研究了微米CaCO3和纳米CaCO3对CPE/PP复合材料性能的影响,微米CaCO3使CPE/PP的拉伸强度提高,但冲击强度降低;纳米CaCO3对CPE/PP同时具有增强和增韧作用,当纳米CaCO3含量为8%时,CaCO3/CPE/PP三元复合材料的综合力学性能较好。  相似文献   

10.
以聚烯烃弹性体POE(乙烯辛烯共聚物)为增韧剂,以纳米CaCO3为增强剂,利用双螺杆挤出机,通过熔融共混工艺制备了聚丙烯(PP)/POE/无机纳米粒子复合材料。测试了复合材料的力学性能并利用扫描电子显微镜(SEM)对三元复合材料的断面形态进行了研究。研究结果表明,利用纳米CaCO3对共混物PP/POE进行改性,存在一个最佳用量,一般为5%左右。采取将纳米CaCO3先与POE混合挤出后再与PP进行共混挤出的二步法工艺,复合体系的综合性能较优。  相似文献   

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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   

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14.
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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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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