乙烯气相聚合流化床反应器内Geldart B类和Geldart D类颗粒流动特性的三维数值模拟

乙烯气相聚合流化床反应器的设计、操作和优化依赖于对聚合物颗粒粒径大小和分布、气泡运动特性及聚合反应状况的准确描述。采用Eulerian-Eulerian 双流体模型和群体平衡模型耦合方法对某乙烯气相聚合中试规模的工业流化床反应器分别处于常规聚合工艺(属Geldart B 类颗粒)和免造粒工艺(属Geldart D 类颗粒)时床体的气固流动特征以及不同颗粒类型对反应器操作状态和颗粒运动特性的影响进行了三维数值模拟研究。与传统聚乙烯生产工艺相比,免造粒工艺时的Geldart D 类聚合物颗粒更易聚集于气体入口处区域,而且会产生明显的旋涡并出现较大的气泡。研究结果可为免造粒聚乙烯生产工艺的工业推广应用提供参考。     

核电厂聚乙烯管道设计方法及标准简介

随着聚乙烯管道在三门核电厂、大亚湾核电厂中的试应用成功,大量的新建核电厂及核电厂改造项目均将聚乙烯管道作为海水冷却水管道系统的首选管材,自主研制核电厂聚乙烯管技术标准迫在眉睫。本文介绍了核电聚乙烯管道的发展历史和应用现状,对比了核安全3级聚乙烯管道和非核安全相关聚乙烯管道、城市燃气与给水聚乙烯管道技术标准的设计方法及适用范围,探讨了中国目前聚乙烯管技术标准与核3级聚乙烯管道技术标准的差异与差距,为核电厂聚乙烯管道的设计制造与标准研制提供参考。     

Unipol气相法聚乙烯技术进展与启示

综述了Unipol催化剂技术中典型的4类聚乙烯(PE)催化剂的特性,介绍了气相法PE装置扩能技术的进展。指出国内PE企业应加快催化剂的国产化进程,装置扩能改造增加生产能力,产品结构定位与调整要适时而变,从而缩短与世界先进水平的差距。     

聚乙烯改性的研究与进展

综述了聚乙烯（PE）的主要特性及分类,并介绍了聚乙烯（PE）的改性,包括填充、共混、接枝、交联及改性后的应用情况,并指出了今后聚乙烯（PE）改性的发展方向。     

湿法磷酸生产中常用的非金属材料：Ⅰ．热塑性塑料

介绍部分热塑性塑料在湿法磷酸中的应用情况。重点介绍了以聚氯乙烯、聚乙烯、聚烯烃、聚丙烯、聚四氟乙烯为代表的热塑性塑料的性能;结合多年的使用经验,提出了在湿法磷酸各部位的热塑性塑料的选用意见。     

世界聚乙烯工业现状及生产工艺新进展

概述了世界聚乙烯（PE）工业生产和消费现状,介绍了PE生产工艺的最新进展,如冷凝及超冷凝技术、不造粒技术、共聚技术、反应器新配置技术、双峰技术等。提出了发展我国PE工业生产的建议。     

交联电缆用LDPE树脂性能及其应用

利用拉伸试验、红外光谱、凝胶渗透色谱、差示扫描量热法、流变表征等方法，对交联电缆用QLT17 LDPE树脂的性能进行了表征分析，研究了以QLT17 LDPE为基础树脂分别制备的硅烷交联和过氧化物交联聚乙烯电缆绝缘料的性能，并介绍了QLT17 LDPE在交联聚乙烯电缆绝缘料中的工业化应用。结果表明，QLT17 LDPE是一种性能优异的交联聚乙烯电缆绝缘料基础树脂。     

Polyethylenes in blown films: Effect of molecular structure on sealability and crystallization kinetics

Three types of polyethylene (PE), with different molecular structure, were selected and used in the production of films using a semi‐industrial blown film extrusion line. Carbon nuclear magnetic resonance and crystallization analysis fractionation tests were performed on the PE polymers to assess their molecular structure. Sealability properties of the films, as well as crystallization kinetics, were evaluated and the results are discussed according to the molecular structures of the polymers. It was found that distribution of short chain branching (average comonomer sequence nH or nO) on the backbone of the PE chains are the main factor controlling the beginning of sealability. The completely random placement of the comononer on the polymer backbone (monomer dispersity 100%) generated crystals with smaller size and a lower melting temperature. Sealing was controlled by crystal distribution, chain diffusion, and entanglement formation at the interface. PE with lower melting point and linear molecular structure showed greater hot tack strength. PE with long chain branching showed a delay on seal process leading to lower sealing speed. POLYM. ENG. SCI., 57:52–59, 2017. © 2016 Society of Plastics Engineers     

Optimization of polyethylene/binder/polyamide extrusion blow‐molded films. III. Slippability improvement with fatty acid amides

The slippability of packaging films has to be controlled to facilitate confectionary operations and guarantee an easy opening for filling. In the case of single‐layer polyethylene (PE) films, the addition of slip agents made of fatty acid amides such as erucamide or oleamide usually allows the tailoring of the coefficient of friction (COF) in the film to match industrial targets, which depend on the final application. The coupling of Fourier transform infrared spectroscopy and atomic force microscopy analysis showed that this method has a limited efficiency and may even be detrimental in the case of multilayer PE + ethylene vinyl acetate (EVA)/maleic anhydride grafted polyethylene (PEgMAH) + EVA/polyamide films. The reason is that the migration of the slip additives toward the outermost surface of the PE layer, which leads to a reduction in the COF, are strongly affected by both the existence of the adjacent layers and the presence of EVA in the PE and PEgMAH layers. Nevertheless, a proper knowledge of the effect of this perturbation allows one to reach a slippability level that is required for some confectionary operations and/or for an easy opening for filling without the degradation of the heat sealability. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

茂金属聚乙烯流变特性的研究

对国产茂金属聚乙烯试验料(mPE)、EXXON公司的茂金属聚乙烯(EXXON)及传统聚乙烯(PE7042)的流变特性进行了对比研究;同时,考察了mPE加入低密度聚乙烯(LDPE)后的流变行为和各种助剂对mPE流变行为的影响,通过研究,发现与PE7042相比,mPE的表观粘度对温度不敏感,容易出现压力振荡,振荡的振幅呈逐渐增加的趋势;LDPE加入量为20%时,mPE的剪切应力、表观粘度明显降低,但LDPE含量继续增加则变化不大.     

淤浆法聚乙烯低聚物的研究

对淤泺法聚乙烯（PE）的生产过程进行了分析，探讨了低聚物产生的原因和进入产品后对PE性能的影响，论述了降低产品低聚物含量和消除低聚物对产品性能影响的方法。     

聚乙烯改性的研究与进展

综述了聚乙烯（PE）的主要特性及分类,并介绍了聚乙烯的改性,包括填充、共混、接枝、交联及改性后的应用情况,并指出了今后聚乙烯改性的发展方向。     

Construction of porous coating layer and electrochemical performances of the corresponding modified polyethylene separators for lithium ion batteries

To effectively improve the affinity of polyethylene (PE) separators with liquid electrolyte without causing a serious pore blockage and to develop a more suitable technology for the industrial production process, porous polyvinylidene fluoride (PVDF) layer‐coated PE separators are prepared by the dip‐coating method followed by a dry‐cast process. Different from previous investigations, a less volatile solvent and a relatively volatile nonsolvent are used to yield a preferable pore structure. A brief introduction on the pore formation mechanism during the dry‐cast process is provided. The pore structure of coating layer is found to be successfully controlled by changing evaporation temperature, nonsolvent content, and PVDF concentration. The porous PVDF coating layer‐modified separators show better affinity with liquid electrolyte and thermal stability. Especially, the ionic conductivity of the modified separator/liquid electrolyte system with a suitable porous coating layer on the separator could reach two times as that of PE separator/liquid electrolyte system, and the cell assembled with modified PE separator shows better cycle performances. This modification process is proved to be a facile, controllable, and effective method for PE separator modification. Meanwhile, this work could provide some theoretical and technical guidance for the production process. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41036.     

中原聚乙烯生产现状及发展建议

介绍了中原乙烯聚乙烯装置的生产运行情况,并与国内外同类装置进行了比较,指出了聚乙烯装置的不足,对下一步发展提出了建议。     

世界聚乙烯新进展

综述了世界聚乙烯的市场及预测、聚乙烯生产工艺和催化剂的最新进展以及国外公司新开发的产品牌号。     

茂名石化PE农用薄膜专用料的生产和开发

概述了我国农用薄膜现状与发展趋势，分析了存在的问题，对茂名石油化工公司的聚乙烯农用薄膜专用树脂的生产和开发提出了建议。     

交联PE电缆用树脂的开发

根据交联聚乙烯（PE）电缆用基础树脂的要求,确定了产品的技术指标及生产工艺,开发了交联PE电缆用树脂QLT17。与国内外同类树脂相比,QLT17具有优良的物理性能和加丁性能,拉伸强度为13．8MPa,断裂伸长率为653％,介电常数（50Hz）为2．2。其关键指标杂质含量符合电力电缆绝缘料使用要求：0．12～0．25mm的杂质为5个／kg,大于0．26mm的杂质为0。推广应用表明,QLT17是一种性能优异的交联PE电缆用基础树脂。     

Immobilization of a cyclodextrin glucanotransferase (CGTase) onto polyethylene film with a carboxylic acid group and production of cyclodextrins from corn starch using CGTase‐immobilized PE film

Carboxylic acid groups were introduced onto polyethylene (PE) film by radiation‐induced graft copolymerization. Subsequently, the clodextrin glucanotransferase (CGTase) was immobilized on the PE film with a carboxylic acid group. The activity of the immobilized CGTase on PE film was in the range of 0.40–1.04 U/cm² per min. The production of cyclodextrins (CDs) from corn starch was examined using the CGTase‐immobilized PE film. The production ratios of CDs using CGTase‐immobilized PE film was in the following order: α–CD > β–CD > γ–CD. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2451–2457, 2002     

Z-N催化剂生产宽/双峰MWD聚乙烯的研究进展

介绍了Ziegler-Natta(Z-N)催化剂在单反应器中生产宽,双峰相对分子质量分布(MWD)聚乙烯(PE)的最新研究进展,概括了Z-N催化剂制备宽／双峰MWDPE的主要方法及特点,即传统的Ti系催化体系生产的双峰PE的MWD较窄,改进的Ti-V双金属催化体系活性高,可以调节MWD,但反应操作难度大。通过加入不同的配合物,调节并改进PE的MWD,取得了较好的实验结果。宽/双峰MWDPE的生产和开发是PE工业发展的一个重要方向。     

聚乙烯原料对高密度聚乙烯土工膜性能的影响

本实验采用吹塑成型工艺,以不同牌号的聚乙烯(PE)树脂为原料生产2 mm厚度双光面高密度聚乙烯(HDPE)土工膜,研究PE原料对HDPE土工膜性能的影响。结果表明:中密度聚乙烯(MDPE)土工膜综合性能优异,主要是由其特有的分子结构(如分子量分布双峰性、α烯烃长支链)所决定的;不同PE原料氧化诱导时间不同,可通过调节含抗氧剂色母料(或抗氧剂)的含量,使HDPE土工膜氧化诱导时间达到要求;HDPE土工膜在焊接时应根据PE材质的不同而选择不同的焊接条件。