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分别以β成核剂二苯基己二酞二胺(NT–C)和芳酰胺类化合物(TMB–5)增韧 PP/EPDM 复合材料,制备了 PP/EPDM/NT–C 复合材料与 PP/EPDM/TMB–5复合材料。研究了β成核剂与 EPDM 的协同增韧效应,以及两种β成核剂对 PP/EPDM 复合材料固化行为及结晶行为的影响。结果表明,在 TMB–5含量相同时,随着 EPDM含量的增加,PP/EPDM/TMB–5结晶速率先增大后减小,在 EPDM 质量分数为10%时达到最佳。在 EPDM 含量相同时,随着 NT–C 含量的增加,PP/EPDM/NT–C 复合材料的结晶速率逐渐提高。 相似文献
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茂金属聚乙烯弹性体和三元乙丙橡胶增韧聚丙烯的比较 总被引:9,自引:1,他引:8
用茂金属聚乙烯弹性体(mPE)代替三元乙丙橡胶(EPDM)对聚丙烯(PP)增韧改性并进行了比较。结果表明,mPE共聚物中的辛烯质量分数越高,其中对PP的增韧效果越好;随着共混物中弹性体质量分数的增加,共混物的拉伸强度和弹性模量降低,扯断伸长率增大。PP/mPE与PP/EPDM增韧体系相比,二者的拉伸强度差别不大,但PP/mPE的弹性模量和扯断伸长率稍低;与EPDM相比,mPE对PP具有较好的增韧效果,含有质量分数40% mPE的共混物试样在-30℃下的缺口冲击强度已超过纯PP的20倍,约是相同弹性体质量分数PP/EPDM的近9倍。另外,PP/mPE还具有较低的拉伸永久变形、压缩永久变形和蠕变变形。 相似文献
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对聚丙烯(PP)/三元乙丙橡胶(EPDM)共混合金的结构与性能进行了研究。结果表明:国产三元乙丙橡胶J3080P能够大幅度提高PP的常温和低温缺口冲击强度;PP基体的性质和EPDM的用量对增韧效果有明显影响。PP/EPDM共混合金发生脆韧转变所需的EPDM用量为20~30份。EPDM对PP增韧机理遵从银纹-剪切带机理。J3080P对PP的增韧效果优于日本产EPDM 501A。 相似文献
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以聚丙烯(T36F)为基料,考察了核-壳结构共聚物(SEP)和三元乙丙橡胶(EPDM)对聚丙烯的增韧作用。结果表明:SEP作为聚丙烯(PP)的增韧添加剂比EPDM有更好的增韧效果。当SEP用量为10phr时,PP/SEP共混材料的缺口冲击强度是纯PP的7.7倍,超过了20份EPDM增韧PP的效果,是优良的PP抗冲增韧改性剂。 相似文献
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《塑料科技》2016,(7):27-31
以聚丙烯(PP)为基体、微晶纤维素(MCC)为增强材料、马来酸酐接枝聚丙烯(PP-g-MA)为相容剂,利用双螺杆挤出机制备了PP/MCC/PP-g-MA复合材料,同时研究了该复合材料的力学性能。随后分别选用三元乙丙橡胶(EPDM)和乙烯-辛烯共聚物(POE)对PP/MCC/PP-g-MA复合材料进行增韧改性,考察了两种增韧剂的增韧效果。结果表明:加入PP-g-MA后,PP/MCC复合材料的力学性能明显提高。另外,增韧剂的引入使PP/MCC/PP-g-MA复合材料的冲击性能显著改善,其中POE对复合材料的增韧效果优于EPDM。但是增韧剂的引入会造成复合材料的拉伸强度、弹性模量和弯曲强度分别出现不同程度的下降,其中EPDM增韧复合材料的上述性能下降幅度相对较小。 相似文献
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高模量弹性体对PP结晶行为及力学性能的影响 总被引:2,自引:0,他引:2
应用DSC和力学性能测试研究了PP/OTE、PP/EPDM共混物的结晶行为和它们的增韧作用。结果表明 ,烯烃类热塑性弹性体 (以下简称OTE)对PP的结晶性能无明显影响 ,EPDM对PP成核速率有促进作用。PP/OTE在赋予PP较好低温韧性的同时 ,使共混物的刚性得以适度兼顾 ,且易于加工。PP/OTE共混体系的综合性能优于PP/EPDM共混物 相似文献
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研究了聚丙烯(PP)基体树脂、增韧剂种类对增韧PP复合材料撕裂力和热氧老化性的影响。结果表明:PP K8003/三元乙丙胶(EPDM)撕裂力高于PP B8101/EPDM,而耐热氧老化性劣于PP B8101/EPDM;三种增韧剂EPDM,乙烯–辛烯共聚物(POE)和苯乙烯–乙烯–丁烯–苯乙烯三嵌段共聚物(SEBS)对增韧PP的撕裂力和热氧老化性影响不同,PP/SEBS复合材料的撕裂力和热氧老化性最好,PP/POE次之、PP/EPDM最差;当POE质量百分数为35%时,PP/POE复合材料的撕裂力为217 N,经140℃×1 000 h热氧老化后拉伸强度和断裂伸长率保持率分别为131%和82%;采用PP/POE复合材料挤出成型的汽车拉索护套各项性能可满足使用要求,达到客户的预期目标。 相似文献
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M. S. J. Simmonds W. M. Blaney F. Delle Monache M. Marquina Mac-Quhae G. B. Marini Bettolo 《Journal of chemical ecology》1985,11(12):1593-1599
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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Cheng-Le Zhao Shane Porzio Alan Smith Haiyan Ge H. T. Davis L. E. Scriven 《Journal of Coatings Technology and Research》2006,3(2):109-115
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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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. 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
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中蓝晨光化工研究院有限公司《塑料工业》编辑部 《塑料工业》2009,37(3)
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
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中蓝晨光化工研究院《塑料工业》编辑部 《塑料工业》2007,35(3):1-25,67
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