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1.
热致性液晶与聚丙烯原位复合材料的相容性研究   总被引:2,自引:0,他引:2  
在热致液晶共聚酯(LCP)与聚丙烯(PP)的共混体系中引入相容剂(接枝共聚物MAH—g-PP),借助热台偏光显微镜、扫描电镜、差示扫描量热仪、流变仪等方法研究了相容剂对PP/LCP原位复合材料的微观结构和界面性能、结晶行为、流变行为以及力学性能的影响.结果表明:添加相容剂后,基体中的LCP微纤分散更均匀,LCP微纤长径比L/D增大.PP和LCP两相之间有较好的粘连,促进了共混体的结晶,改善了PP/LCP原位复合材料的力学性能.  相似文献   

2.
PP/EPDM/云母共混复合材料的研究   总被引:6,自引:0,他引:6  
马懿  宗明 《中国塑料》1996,10(1):10-16
冲击强度和弯曲模量是聚丙烯共混材料中存在的一个矛盾,通过PP/EPDM/云母三元共混得一以具有高冲击强度和高弯曲模量的硬而韧的复合材料,并将其用于汽车塑料件中。本文研究了PP/EPDM/云母的共混物配方、共混体系中EPDM和云母含量与冲击强度和弯曲模量间的关系,分析了云母的表面处理及PP/EPDM/云母材料断面SEM照片,提出了该材料的结构形态模型。  相似文献   

3.
LMPM/PP复合材料中PP的晶型结构   总被引:8,自引:2,他引:6  
用宽角X射线衍射(WAXD)研究低熔点金属(LMPM)/PP复合材料中的PP的晶型结构,结晶度β晶型含量以及α-晶型的微观尺寸,发现LMPM用量增加,LMPM粒径减小,加和偶联剂以及提高混炼转速有利于PP形成β-晶型,并使α-晶型的微观尺寸变小,但结晶度变化不大,这种规律归结于LMPM的异相成核作用以及复合材料在冷却时内部大的温度新梯度。  相似文献   

4.
PP/AS/DCP反应共混中SEBS的添加效应   总被引:4,自引:0,他引:4  
研究了在聚丙烯(PP)/丙烯腈-苯乙烯共聚物(AS)/过氧化二异丙苯(DCP)共混物反应挤出过程中添加热塑弹性体氢化(苯乙烯-丁二烯-苯乙烯共聚物)(SEBS)对PP/AS共混物降解的抑制效果对接枝反应的促进作用。对反应经物中PP相MFR、红外测试及扫描电子显微镜与航向电子显微镜对共混物的观察结果表明,加入SEBS不但可以抑制反应共混中PP和AS的降解,而且可以大大促进反应共混中的接枝反应的进行,  相似文献   

5.
用等规聚丙烯与马来酸酐的固相接技法制得具有不同酸值的改性聚丙烯树脂(PP—g—MA),并将PP—g—MA与环氧/聚酯粉末涂料共混,研究了共混物的膜性能。结果表明,PP—g—MA作为环氧/聚酯粉末涂料的一个组分用于粉末涂料,具有很好的膜性能。  相似文献   

6.
卢秀萍  韩英素 《中国塑料》1999,13(12):24-28
系统研究了不同组成及配比的马来酸酐接枝聚丙烯(MAH-g-PP)及其用量对聚丙烯(PP)与乙烯-乙烯醇共聚物(EVAL)的共混体系(PP/EVAL)力学性能借用Brabender塑化仪测试了PP/EVAL/MAH-g-PP共混体系的加工性能。结果表明,MAH-g-P接枝物对PP/EVAL共混体系有较好的增容作用,适量加入,可使PP/EVAL共混体系的力学性能明显提高,而加工性能基本不变。  相似文献   

7.
硫酸钙晶须/PP/EPDM复合材料力学性能研究   总被引:13,自引:0,他引:13  
采用对硫酸钙晶须进行表面处理和提高PP/EPDM基体树脂极性的方法制得具有良好界面层的硫酸钙晶须/PP/EPDM复合材料。力学性能测试结果表明,硫酸钙晶须可提高PP/EPDM基体的拉伸强度和弯曲强度,通过控制各组分配比可制得韧性和刚度均衡的复合材料。  相似文献   

8.
研究了EPDM/PP共混型热塑性弹性体对三种聚丙烯的增韧改性,使用较少的EPDM制得较高悬臂梁制品冲击强度的增韧聚丙烯,材料的拉伸强度和弯曲弹性模量仍能满足使用要求。研究了TPR的交联密度对PP/TPR共混物塑化特性和流变性能的影响,表明所得共混物属于切敏型假塑性流体。  相似文献   

9.
将两种熔融流动指数(MFI)相差大的聚丙烯(PP)分别与一低密度聚乙烯(LDPE)进行共混,用熔体流动速率仪测定其流动特性。发现MFI值高的PP,当共混比PP/LDPE为50/50时,其熔体流动速率(MFR)为最大,本文对此作了初步的分析和讨论。  相似文献   

10.
PP/EPDM硫化与非硫化共混物微观形态及流变行为的研究   总被引:2,自引:0,他引:2  
曹明  赖逸云 《塑料工业》1996,24(6):80-83
本文采用二段共混方法,先制得PP/EPDM硫化与非硫化增韧母料,该两种母料对PP的改性,其共混物的微观形态及宏观力学性能显示极大的差异。所采用的硫化剂可以使PP/EPDM共混物中的EPDM发生动态硫化作用,且使PP接枝于EPDM交联网络上。非硫化体系中EPDM呈根须状分布于PP球晶之间和内部;而硫化体系中,EPDM主要分布于球晶间,与PP相呈“海-岛”结构,并与PP球晶有很好的界面过渡。在EPDM含量相同的情况下,硫化体系比非硫化体系具有更高的耐冲击强度,且EPDM含量愈多时,这种效果愈加明显。流变行为分析表明,PP/EPDM共混物属于假塑性流体(n<1),在一定剪切速率下,EPDM含量的增加及EPDM的硫化,都使共混物的表观粘度ηa增加,挤出膨胀比B减小,非牛顿指数n减小,非牛顿流体性质更明显。  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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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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