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以单螺杆挤出机为裂解设备,聚乙烯951-050及2426 H为裂解原料,制备了聚乙烯蜡(PEW)产品,研究了聚乙烯蜡黏均分子量和熔点随螺杆的转速、裂解温度的变化规律,分析了氮气保护以及冷却工艺对聚乙烯蜡性能的影响。结果表明,聚乙烯蜡的熔点和黏均分子量均随着螺杆转速的增加而增加,随着裂解温度的增加而降低。在较高的螺杆转速内,裂解温度对聚乙烯蜡产物熔点的变化影响较小。当空气存在的条件下,聚乙烯裂解程度加深,产物颜色加深;相对于自然冷却法,聚乙烯蜡喷粉法降低了聚乙烯蜡的结晶能力,使聚乙烯蜡熔点降低。 相似文献
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溶剂辅助聚乙烯废塑料裂解制聚乙烯蜡 总被引:1,自引:0,他引:1
采用溶剂辅助裂解方法来提高聚乙烯(PE)废塑料裂解制聚乙烯蜡的收率,同时对产品质量加以改善。通过筛选得出最佳溶剂及其加入量,考察了裂解温度和时间对产物收率的影响并对产物进行结构分析。结果表明,加入质量分数10%的混合二甲苯,在反应温度425℃和15 min裂解条件下,得到聚乙烯蜡,产物收率为87.88%;加入混合二甲苯不会改变聚乙烯蜡分子结构,不会残留在产物中;裂解产物熔点约为97.8℃,粘均相对分子质量为1 264.6。 相似文献
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本刊:于总,请您简单介绍下自己和天诗公司.
于总:我1989年创立辽宁昌图橡塑材料厂,主要从事PE母料的开发和生产,从那时候起开始研究聚乙烯蜡,研究聚乙烯蜡的裂解法生产技术、氧化技术、改性技术,聚乙烯蜡的提纯和精制方法.2000年前后受聘于齐齐哈尔大学材料研究所,对外转让聚乙烯蜡生产技术.2003年开始探索用超临界CO2喷雾法生产微粉蜡,自己设计了专门的工艺和设备,后来成立南京天诗实验微粉有限公司,向涂料油墨、塑料橡胶行业推广这种新产品,我们的微粉蜡市场占有率全国数一数二. 相似文献
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以废旧线性低密度聚乙烯(LLDPE)为原料,采用压力反应釜在封闭条件下通过热裂解方法制备聚乙烯蜡(PE蜡),研究了裂解时间、温度和压力对产物的产率、分子量和滴熔点的影响,并通过红外光谱对产物的官能团进行了分析。实验结果表明,在裂解时间为15~60 min,裂解温度约为260℃的条件下,LLDPE裂解所得到的PE蜡性能较佳,其主要成分为直链烷烃和烯烃,滴熔点大于100℃,黏均分子量处于1400~4700;由动力学分析可知,由于封闭反应体系增加了反应压力,降低了裂解温度和活化能,促进了LLDPE裂解反应进行,同时抑制了气体分子的产生,有利于获得PE蜡。 相似文献
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本文以废旧聚乙烯为原料,在溶剂水的作用下进行裂解制备聚乙烯蜡。实验过程中考察了温度、时间及溶剂加入量对产品性能的影响。结果表明:随裂解温度的升高和反应时间的延长都使得反应体系获得了更高的能量,容易使PE大分子发生断链从而得到低分子量PE,从而使产物收率逐渐降低,粘均分子量减少,熔程也随之下降。溶剂加入量对产品性质也有一定影响。当裂解温度为370℃,反应时间60min,溶剂加入量占原料总质量50%时,得到灰白色的聚乙烯蜡,其熔程在104~110℃之间,酸值为0.0143mg·g-1,粘均分子量为3426.4,且具有较高的热稳定性。通过溶剂裂解制得的聚乙烯蜡具有一定的工业应用前景。 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