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The effect of benzoyl peroxide (BPO) on polypropylene (PP) degradation in supercritical water was investigated with the aim of developing a process for recycling of waste plastics. A series of experiments with and without BPO were carried out at temperatures of 653 K and 673 K under pressure about 26 MPa for 30, 75 and 120 min respectively. Products were analyzed by an Ostward-type viscometer, gas chromatography and spectrometry (GC/MS) etc. The results indicated that mean molecular weight of the samples decreased greatly along with the time elapsing or with the temperature increasing, and PP was decomposed to Miphatic and cycloparaftinic hydrocarbons but a few benzenoid hydrocarbons. By comparing the experiments with and without BPO, it was made clear that BPO is an effective additive on PP degradation in supercritical water. 相似文献
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超临界水降解聚丙烯的工艺研究 总被引:1,自引:0,他引:1
采用间歇式管式反应器进行了超临界水降解聚丙烯实验,研究了影响聚丙烯降解的因素。实验结果表明,在温度400-450℃、压力23-35MPa及反应时间60-120min的条件下,超临界水能有效地降解聚丙烯。反应温度和反应时间是影响聚丙烯降解的主要因素,温度越高、时间越长,聚丙烯降解越彻底;聚丙烯颗粒度越小降解速率越快,粉末原料在温度400℃、反应时间60min时,以油相产物为主;在温度450℃、反应时间120min时,有利于得到气相产物。 相似文献
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在超临界水中聚苯乙烯泡沫的降解 总被引:8,自引:0,他引:8
本文研究了聚苯乙烯泡沫在超临界水中的降解反应。考查了反应时间、温度和添加剂对降解反应的影响。实验结果显示,超临界水能将聚苯乙烯泡沫降解为油状产物。在反应的前30min内,分子量降低了约98%;提高温度对反应时间短的和/或无添加剂的配方有明显的促降解作用;添加剂用量在5%左右时,可得到更大的效率/成本比。 相似文献
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ε-酸在超临界水中的氧化降解 总被引:21,自引:0,他引:21
实验研究了典型有机污染物ε -酸在超临界水中的氧化降解.结果表明,超临界水氧化技术能有效地降解废水中的有机污染物,COD去除率可达99%以上.随着反应温度的升高、压力的增大、停留时间的延长和初始废水浓度的增大,COD去除率也随之提高.ε-酸在超临界水中氧化降解的动力学方程为:-d[COD]/dt =9.75104exp(-8.3804/RT)[COD]1.06[O2]00.165 相似文献
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超临界水氧化法降解葡萄糖的研究 总被引:9,自引:0,他引:9
实验研究了葡萄糖在超临界水中的氧化降解。结果表明 ,超临界水氧化技术能有效地降解废水中的葡萄糖 ,COD去除率可达 98%。随着反应温度的升高、压力的增大、停留时间的延长和初始废水浓度的增大 ,COD去除率也随之提高。葡萄糖在超临界水中氧化降解的动力学方程为- d[COD]dτ =2 4.2 exp - 3.0× 10 4RT [COD]1.0 3 [O2 ]0 .0 670 相似文献
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磺酸萘在超临界水中氧化降解路径的研究 总被引:4,自引:0,他引:4
采用GC-MS对1-氨基-2-羟基-4-磺酸萘有机污染物在超临界水中氧化降解的产物进行了分析和鉴别,通过对中间产物的鉴别和结合相关研究提出了其在超临界水中氧化降解的路径。1-氨基-2-羟基-4-磺酸萘氧化降解的路径可用纵横交叉模式描述,即纵向的氧化开环降解反应和横向的耦合反应,该污染物及其带芳环中间产物进一步氧化都经过苯酚,并由其继续开环氧化降解。 相似文献
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Hisayuki Nakatani Hiroshi Shibata Kensuke Miyazaki Tetsu Yonezawa Hidetoshi Takeda Yutaka Azuma Shin Watanabe 《应用聚合物科学杂志》2010,115(1):167-173
In this study, an effect of iron oxide (Fe2O3) impurity in talc on degradation behavior of polypropylene (PP)/talc composite was studied using a PP/Fe2O3 model composite sample. The thermal oxidative degradation was performed at 100°C. Although the degradation of a pure PP sample hardly occurred at such temperature, the existence of Fe2O3 induced the PP degradation. The degraded PP part was formed around the Fe2O3 grain in the PP/Fe2O3 sample. It was found from the optical microscope observation that the degraded PP was able to diffuse only within the PP amorphous part. The analysis of the oxidation distribution on the degraded PP surface was performed employing a scanning electron microscope/electron dispersive spectrometer. The result showed that the PP spots in the vicinity of the Fe2O3 grain were unoxidized during the initial degradation process, and the oxidized PP spots were located at around 6 μm distance from the Fe2O3 grain. It was concluded that the degradation was initiated microscopically away from the Fe2O3 grain so that the Fe2O3 had both the abilities to accelerate the decomposition of PP hydroperoxide compounds and to reduce the produced radical species into nonradical products. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
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J. Liu M. R. Thompson M. P. Balogh R. L. Speer Jr. P. D. Fasulo W. R. Rodgers 《应用聚合物科学杂志》2011,119(4):2223-2234
Supercritical carbon dioxide (scCO2) has been proposed as an effective exfoliating agent for the preparation of polymer‐layered silicate nanocomposites, though there is limited fundamental understanding of this mechanism. This study looks at the interactions of this unique green solvent with three maleated polypropylenes of varying anhydride content and molecular size with an alkyl‐ammonium organoclay. Mixtures of compatibilizers and organoclay were melt‐annealed in a high pressure batch vessel at 200°C and subjected to either a blanket of nitrogen or scCO2 at a pressure of 9.7 MPa. The structures and properties of these melt‐annealed mixtures were characterized by X‐ray diffraction, transmission electron microscopy, Fourier Transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, differential scanning calorimetry, and contact angle measurement. The results indicate that the plasticizing influence of scCO2 aided intercalation and exfoliation for intercalants of moderate molecular size and anhydride content which would otherwise have limited diffusion into the clay galleries. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
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通过广角X射线衍射(WAXD)对由丙烯超临界聚合和传统本体淤浆法制得的等规聚丙烯原生结晶特征进行了研究,并讨论了聚合工艺、预聚温度、粒径、分子量等对原生晶特征的影响。结果表明,超临界聚合法制备的等规聚丙烯(SC-iPP)呈现出α和γ的混合晶型,而采用传统淤浆法制备的等规聚丙烯(C-iPP)只含有单一α晶型,这是因为超临界的高温高压状态,使得体系传热传质阻力较小,更有利于原生晶型的发展。此外,预聚温度、粒径、分子量等因素也对丙烯超临界聚合所制得的SC-iPP结晶特征有显著影响。 相似文献
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Hisayuki Nakatani Norio Manabe Yoshimitsu Yokota Hiroaki Minami Shoutarou Suzuki Fumitaka Yamaguchi Minoru Terano 《Polymer International》2007,56(9):1152-1158
Thermal oxidative degradation of polypropylene impact copolymer has been studied with its fractions obtained using the temperature rising elution fractionation method. The fractions were analyzed using 13C NMR, Fourier transform infrared and differential scanning calorimetry measurements, and the chemical structure, isotacticity, conformation and melting point were investigated. It is found that these fractions are composed of a homopolymer or a polymer blend of polypropylene, polyethylene and ethylene–propylene copolymer. The thermal oxidative degradation of each fraction was carried out at 130 °C, and the degradation progress was estimated by the change of molecular weight distribution (from gel permeation chromatography curves). The rate of degradation is found to be dominated by the content of tertiary C? H bonds (propylene unit) and the existence of 31 helix conformation corresponding to a crystalline polypropylene part in each fraction. The latter is more evident leading to the degradation reaction path with a lower activation energy. Copyright © 2007 Society of Chemical Industry 相似文献