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1.
采用Horizone工艺生产了高刚抗冲共聚聚丙烯K7010。通过对比分析催化剂体系、熔体流动速率(MFR)控制方法、乙烯和橡胶含量的控制方法,确定了生产工艺条件。将均聚部分的MFR控制在15~20 g/10 min,总MFR控制在10 g/10 min,总乙烯质量分数为4.5%,橡胶相质量分数为12.5%,橡胶相中乙烯质量分数为38%,K7010获得了优异的刚韧平衡性,与进口产品相比,弯曲模量和简支梁缺口冲击强度均大幅提高,弯曲模量提高了13%,常温简支梁缺口冲击强度提高了37%,其他指标也达到进口同类产品水平。  相似文献   

2.
本文介绍聚丙烯抗冲共聚物的生产工艺和产品的结构性能,针对低温冲击强度对聚丙烯抗冲共聚物的重要性做了阐述,同时结合抗冲聚丙烯EPS30R从工艺控制的角度出发,着重从生产过程中的乙烯用量、氢气用量、催化剂选型、橡胶含量、MFR、凝胶体含量、和停留时间几个方面进行了认真的分析,得出了提高产品低温冲击强度的有效途径。总结抗冲共聚聚丙烯结构研究方法及发展方向,以利于抗冲共聚聚丙烯新产品的进一步开发。展望了抗冲共聚聚丙烯领域的某些可能发展。  相似文献   

3.
考察了以煤为原料生产的高流动抗冲聚丙烯2240S与其对比牌号石油基聚丙烯YP和AR偏光显微镜的结晶形貌、液氮淬断样品断口形貌、热力学性能和基本物理性能等。结果表明,三种样品综合性能相当,均能满足下游加工应用客户和改性应用客户需求,但存在一定差异。2240S刚性好,弯曲弹性模量达到1 239 MPa,但韧性略低,常温冲击强度7.0 k J/m^2,需要合理控制乙丙橡胶相的含量,分布及形态,提高产品冲击性能;YP刚性低,弯曲弹性模量达到1 091 MPa,但韧性最好,常温冲击强度11.0 k J/m^2,需降低乙烯和乙丙橡胶相含量,优化产品分子结构,提高产品刚性;AR达到刚韧平衡,弯曲弹性模量为1 175 MPa,常温冲击强度7.9 k J/m^2,乙丙橡胶相粒子大小和分布均匀、综合性能最佳。  相似文献   

4.
在Horizone工艺装置上成功开发了中熔体流动速率(MFR)高橡胶含量抗冲共聚聚丙烯K7116,并表征了其结构,分析了其性能,讨论了不同因素对K7716力学性能的影响。结果表明:K7116的MFR为16 g/10 min,弯曲模量达1 270 MPa,冲击强度为12 kJ/m2;乙丙橡胶含量增加,使K7116的刚性降低,冲击强度增加;橡胶含量、乙丙橡胶部分与均聚聚丙烯部分的相对分子质量比,以及助剂选择对K7116的结晶性能和力学性能均有较大影响。  相似文献   

5.
使用回收的洗衣机壳料为主要原料,加入回收的酱油壶料进行共混改性,研究酱油壶料加入量对共混料熔体流动速率(MFR)、拉伸性能、冲击性能的影响,确定最佳配料比。结果表明:回收的洗衣机壳料主要成分为聚丙烯(PP)、回收的酱油壶料主要成分为聚乙烯(PE),二者相容性好,加工性能优异。加入回收酱油壶料,可以提高回收洗衣机壳料的强度和韧性。最佳配料比为酱油壶料含量为40%,此时共混料的MFR为0.258 g/10 min、抗拉强度为23.56 MPa、断裂伸长率为12.7%、冲击强度为10.98 k J/m2。  相似文献   

6.
通过双螺杆挤出机制备了聚丙烯(PP)/有机硅热塑性弹性体(Si-TPE)共混物。研究了SiTPE用量对共混物力学性能、结晶性能和熔体流动速率(MFR)的影响,并通过红外光谱、SEM表征了共混物结构。结果表明,随着Si-TPE用量的加大,拉伸强度、拉断伸长率、冲击强度和结晶温度均先升高后降低,MFR增大但不明显;Si-TPE质量分数为5%时,Si-TPE在PP基体中以孤立的橡胶粒子形式存在,粒径为50~500 nm。Si-TPE的最佳用量为2.5%(质量分数),此时,共混物的拉伸强度高达36.6 MPa,拉断伸长率为314%,冲击强度为6.1 k J/m2,MFR为1.6 g/10min。  相似文献   

7.
通过对抗冲共聚聚丙烯(PP)CX9530与国内外同类树脂进行力学性能比较和微观结构表征,认为CX95300抗冲击性能较差的原因在于PP基体中的橡胶相分散性较差,橡胶相尺寸较大。通过调整PP装置气相反应釜内的乙烯与丙烯摩尔比、停留时间等工艺参数,在对CX9530刚性影响较小的情况下,将其常温简支梁缺口冲击强度由10.2 kJ/m~2提升到13.9 kJ/m~2,低温简支梁缺口冲击强度由6.8 kJ/m~2提升到7.5 kJ/m~2,达到国内外同类树脂的水平。  相似文献   

8.
以乙烯、丙烯、1-丁烯为原料,采用美国Ineos公司的Innovene气相聚丙烯工艺技术制备了三元共聚聚丙烯TF1007。介绍了TF1007的试生产过程,并将其与国内外同类聚丙烯进行了对比剖析。结果表明:TF1007中乙烯质量分数3.0%,1-丁烯质量分数7.4%,熔体流动速率7.1 g/10 min,弯曲模量724 MPa,简支梁缺口冲击强度7.1k J/m2,熔点132℃,起始热封温度小于113℃,热合强度11.5 N/15 mm,产品结构、主要性能与市场主流产品相当,各项指标均能满足客户使用要求,并得到用户认可。  相似文献   

9.
针对高流动抗冲击共聚聚丙烯K7227H生产过程中出现的冲击强度波动的情况,采用凝胶渗透色谱仪、红外检测器和扫描电子显微镜等分析了K7227H的相对分子质量、乙烯含量、橡胶相含量和相态结构对其力学性能的影响。从工艺控制的角度出发,在保证产品刚性情况下,通过调整第一气相反应器和第二气相反应器中产品的熔体流动速率比以及第二气相反应器中氢气与乙烯的摩尔比,在总乙烯质量分数为6.81%时,K7227H的常温冲击强度提高到11.1 k J/m~2,实现了K7227H在较低乙烯含量情况下具有较高的冲击强度。  相似文献   

10.
利用粉体助剂的特殊表观性能,将其引入到丙烯聚合反应体系,显著提高了高抗冲聚丙烯颗粒的流动性,得到了高抗冲聚丙烯颗粒,对所得产品进行表征。结果发现,颗粒表面均匀地分布着粉体助剂,产品乙烯质量分数可达22.10%,橡胶相含量可达33.1%,简支梁低温冲击强度为14.10 kJ/m2同时能保持较好的刚性。利用13CNMR对产品进行分析,明确了所得产品的序列结构。  相似文献   

11.
12.
It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.  相似文献   

13.
14.
Scentless plant bugs (Heteroptera: Rhopalidae) are so named because adults of the Serinethinae have vestigial metathoracic scent glands. Serinethines are seed predators of Sapindales, especially Sapindaceae that produce toxic cyanolipids. In two serinethine species whose ranges extend into the southern United States,Jadera haematoloma andJ. sanguinolenta, sequestration of host cyanolipids as glucosides renders these gregarious, aposematic insects unpalatable to a variety of predators. The blood glucoside profile and cyanogenesis ofJadera varies depending on the cyanolipid chemistry of hosts, and adults and larvae fed golden rain tree seeds (Koelreuteria paniculata) excrete the volatile lactone, 4-methyl-2(5H)-furanone, to which they are attracted.Jadera fed balloon vine seeds (Cardiospermum spp.) do not excrete the attractive lactone. Loss of the usual heteropteran defensive glands in serinethines may have coevolved with host specificity on toxic plants, and the orientation ofJadera to a volatile excretory product could be an adaptive response to save time.Mention of a commercial product does not consititute an endorsement by the USDA.  相似文献   

15.
16.
2008~2009年世界塑料工业进展   总被引:4,自引:1,他引:3  
收集了2008年7月~2009年6月世界塑料工业的相关资料,介绍了2008~2009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、环氧树脂、不饱和聚酯树脂)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   

17.
建立了测定地球化学样品中包括As、Cr、Ge、V等18种微量、痕量元素的ICP-MS方法。地化试样用HF-HNO3混酸分解后,以1 1 HNO3溶解干渣。由于制样不使用盐酸,避免了Cl对As、Cr、Ge、V的质谱干扰。用国家一级地球化学标准物质GBW 07309制备溶液优化仪器工作参数,并用于校准。方法测定限(6s)为:0.007~6.4μg/g,精密度(RSD%,n=12)为:29%~9.4%,经过国家一级地球化学标准物质的分析验证,结果与标准值吻合。方法已应用于国土资源调查的试样分析。  相似文献   

18.
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   

19.
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   

20.
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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