国内外氯化聚乙烯生产应用概况

氯化聚乙烯(CPE)是由聚乙烯氯化而制得的产品,用途广泛。本文介绍了CPE国内外生产应用概况,并对我国发展CPE提出了建议。     

国内外聚乙烯生产现状及市场分析

聚乙烯是合成树脂中用量最大的品种,具有良好的机械性能和化学稳定性,广泛用于工业、农业、医药、卫生和日常生活用品等。本文综述了国内外聚乙烯的生产现状,并对聚乙烯的市场、价格及进出口情况进行了分析及预测,对今后我国及中油公司聚乙烯的发展提出了一些建议。     

国内外聚乙烯生产现状及市场分析

综述了国内外聚乙烯的生产现状，并对聚乙烯的市场、价格及进出口情况进行了分析及预测．对今后聚乙烯的发展提出了一些建议。     

氯磺化聚乙烯国内外生产与应用概况

综述氯磺化聚乙烯的生产方法、用途以及国内外生产消费现状,并对国内的生产发展提出了建议。     

氯磺化聚乙烯国内外生产与应用概况

本文综述了氯磺化聚乙烯的生产方法、用途以及国内外生产消费现状,并对国内的生产发展提出了建议。     

国外聚乙烯生产及消费进展

综述了国外聚乙烯生产及消费的进展,特别是重点分析了生产技术的改进及发展,如Unipol工艺、BP工艺、Spherilene工艺、Phillips工艺等技术进展。金属茂催化剂可使聚合物性能优化,并使聚烯烃经历新的革命。文章也叙述了Exxon、Dow、Mobil、BP及三井油化等公司金属茂研究开发的成果,及其在聚乙烯工业中的应用。     

国内外聚乙烯生产现状及市场分析

聚乙烯是合成树脂中用量最大的品种,具有良好的机械性能和化学稳定性,广泛用于工业、农业、医药、卫生和日常生活用品等。本文综述了国内外聚乙烯的生产现状,并对聚乙烯的市场情况进行了分析及预测,对今后我国聚乙烯的发展提出了一些建议。     

国内外钛白粉生产、消费及需求预测

本文对世界钛白粉的生产、消费及市场需求作了预测，对美国、西欧、日本等发达国家作了重点介绍；同时对国内钛白粉工业的生产情况、进出口情况、消费情况及需求作了预测。     

国内外聚乙烯管材专用料的生产技术

详细论述了国内外聚乙烯管材专用料的生产技术,并介绍了国内外聚乙烯管材专用料前沿技术及产品,对今后我国聚乙烯管材专用料的开发方向提出了建议。     

国内外聚碳酸酯的生产、消费与市场

聚碳酸酯（PC），学名2，2－双（4－羟基苯基）丙烷聚碳酸酯，即通常所称的双酚A型聚碳酸酯。是一种无定形的、无味、无臭、无毒、透明的热塑性聚合物，具有机械、热及电等综合性能，特别是耐冲击、蠕变小、制品尺寸稳定，它与ABS、PA、POM、PBT以及改性PPO一起被称为六大通用工程塑料。是六大通用工程塑料中唯一具有良好的透明性能品种，且以冲击强度高而称。在工程塑料中消费量仅次于聚酰胺，是性能均衡，用途广泛的重要品种，在国民经济的各个领域中有着广泛的用途。聚碳酸酯自1956年问世以来，首先在德国工业，以后陆续在日本、西欧、美国实现了工业化，到80年代其生产能力已发展40余万吨／年。最早的PC树脂的合成工艺主要为酯交换法和双酚A溶液光气法，这两种工艺现在都已被淘汰。目前所有的双酚A型PC树脂生产都采用双酚A钠盐光导界面缩聚法。     

Recycling polyethylene from automotive fuel tanks

Polyethylene (PE) from postuse automotive fuel tanks is considered a valuable material for mechanical recycling, and we assessed its properties, paying particular attention to transport properties and processability. The characterization included the study of the sorption–desorption isotherms, the rheological analysis of the molten materials and their processability. In particular, we obtained, sorption‐–desorption isotherms using a model molecule (n‐heptane) to simulate contact with the fuel. The measurements were carried out on films of PE blend for tanks and separately on the components of the blend. Rotational rheometry was carried out on scraps from used tanks and on virgin material for comparison. We performed some extrusion tests to evaluate the possibility of mechanical recycling of the postuse materials. In particular, we examined the melt‐fracture incoming conditions by making use of a twin‐screw extruder with a round die. Stress–strain measurements were carried out on films of virgin and used material, obtained with a press on a laboratory scale to evaluate the change of the mechanical properties of a manufacture obtained by reprocessing a polymer aged in contact with a mixture of liquids. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 347–351, 2002     

Solubility and diffusivity of cyclohexane in high density polyethylene

The diffusivity and solubility of cyclohexane in a high density polyethylene, HDPE, were studied using a gravimetric, quartz‐spring, sorption balance. Solvent concentrations up to a weight fraction of 0.15 over a temperature range of 90 to 160°C were measured. Diffusion coefficients in the range of 10^?6 to 10^?7 were determined. Two types of polymer samples were used: a commercial bead form and flat sheets prepared by melting the polymer. Within the experimental error no differences were observed between the two forms indicating that there were no significant effects caused by the melting and compression. The solubility of cyclohexane in the HDPE as a function of the activity of the cyclohexane was linear. Above the melt temperature the solubility data were predicted better by the group‐contribution, lattice‐fluid equation of state (GCLF‐EoS) than by the van der Waals free‐volume (UNIFAC‐vdw‐FV) model. Below the melt temperature a correction factor for the elasticity significantly improved the predictions for both models. Although the HDPE has a crystallinity of 77.6%, the experimental data and the Vrentas‐Duda free‐volume theory indicated no significant tortuosity effects. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Physical properties of polyethylene/silicate nanocomposite blown films

Maleated polyethylene/silicate nanocomposite and maleated polyethylene/SiO₂ blown films were prepared by melt extrusion. The silicate and SiO₂ significantly affected the physical properties of the films. The former films showed higher tensile strength than the latter films. This high reinforcement effect seemed to be attributable to the strong interaction between the matrix and silicate as well as the uniform dispersion of silicate layers in the polymer matrix. The addition of silicate beyond a certain content gave a worse Elmendorf tear strength than SiO₂. The silicate did not increase the falling dart impact strength at all. The worst Elmendorf strength apparently originated from the orientation of anisotropic silicate rather than the orientation of lamellae of the polymer matrix, and the silicate made the films more brittle. The well‐dispersed silicate layers in the polymer matrix gave almost the same optical properties as the pure polymer despite the increase in the silicate content. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2131–2136, 2003     

Modification of properties of CaCO3‐polymerization‐filled polyethylene

CaCO₃–polyethylene (PE) compositions, containing an ultrahigh molecular polyethylene (UHMPE) interlayer between the filler surface and the PE matrix, were synthesized by two‐step polymerization of ethylene on a filler surface activated with a suitable catalyst. The properties of the compositions were studied depending on the molecular weight of the PE matrix and the thickness of the UHMPE intermediate layer at the filler particles. It was shown that the presence of UHMPE as an interlayer in chalk–UHMPE–PE compositions leads to an increase of plastic deformation of the materials as long as the M_w value of the PE matrix is higher than is the brittleness threshold for PE. Chalk–UHMPE–PE compositions exhibit a higher ability for plastic deformation compared to chalk–PE compositions based on a PE matrix of a molecular weight equal to the molecular weight of the total polymer phase (UHMPE–PE) in the first case. There is no improvment of the mechanical properties when the UHMPE is dispersed in the compositions and not as an interlayer between a filler and a matrix. This means that the method of polymerization filling allows one to incorporate the polymer interlayer with a desired nature and properties between a filler surface and polymer matrix in filled polyolefin compositions. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 577–583, 2003     

Phase structural analyses of polyethylene extrusion coatings on high‐density papers. II. Influence of paper surface properties on the polyethylene morphology

Paper samples of three different qualities were extrusion coated with low‐density polyethylene (LDPE) and high‐density polyethylene (HDPE). The morphological phases of the polyethylene layers have been quantified by ¹³C solid‐state high‐resolution NMR. Shear forces in the process initiate the formation of the monoclinic crystallites. The surface tensions of the high‐density papers have influence on the degree of interaction between the two materials and how these shear forces work. The paper surface properties will thus have an influence on properties and the size of the monoclinic crystalline mass fraction of the polyethylene coating. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 226–234, 2004     

Structure and properties of ultraviolet‐irradiated high density polyethylene at different environmental temperatures

C? O, C?O, and C(?O)O oxygen‐containing groups were introduced onto the molecular chain of high‐density polyethylene (HDPE) through ultraviolet irradiation in air. The introduction rate of the oxygen‐containing groups onto HDPE increased with increasing environmental temperature. After ultraviolet irradiation, the molecular weight of HDPE decreased, and its distribution became wider; the melting temperature, contact angle with water, and impact strength decreased; the degree of crystallinity and yield strength increased; and their variation amplitude increased with environmental temperature. The environmental temperature had an effect on the gel content of irradiated HDPE. HDPE‐irradiated for 48 h at 35° and 50°C were not crosslinked. However, gelation took place in HDPE irradiated for 24 h at 70°C. HDPE irradiated at a high environmental temperature was more effective than that irradiated at a low environmental temperature in compatibilizing HDPE with PVA. Compared with the 83/17 HDPE/PVA blend, the yield and notched impact strength of the 73/17 HDPE/PVA blend compatibilized with 10% HDPE irradiated for 24 h at an environmental temperature of 70°C increased from 30.8 MPa and 110 J/m to 34.9 MPa and 142 J/m, respectively. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2966–2969, 2003     

Correlations between the processing variables and morphology of crosslinked polyethylene

Crosslinked polyethylene (XLPE) is progressively replacing other types of polyethylene in electric cable insulation because of its combination of better mechanical and thermal performance and good dielectric properties. Besides its influence on the mechanical and thermal properties, the morphology plays a very important role in the electrical behavior of XLPE. The morphology has been studied in terms of the crystallinity and crosslinking density. These two apparently independent parameters govern the morphology of XLPE and have been investigated in connection with the systematic variation of the processing parameters (crosslinker concentration, cure time, and temperature). The materials have been characterized in terms of the extent of crosslinking (the gel content), the crosslinking density (the average molecular weight between crosslinks), and the crystallinity. A morphological model is proposed for these materials in terms of the mechanisms and rates of the processes involved. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 222–230, 2004     

Crosslinking of high‐density polyethylene in the presence of organic peroxides

The crosslinking efficiency of various commercially available organic peroxides (dicumyl peroxide, O,O‐t‐butyl O‐2‐ethylhexylperoxycarbonate, t‐butyl peroxybenzoate, t‐butyl 3,5,5‐trimethylperoxyhexanoate, and t‐butyl 2‐ethylperoxyhexanoate) was tested on high‐density polyethylene (HDPE) in its molten state. The variations of the concentrations of the peroxides versus the crosslinking extent were plotted for these peroxides, and the values were compared. Dicumyl peroxide was found to be the best crosslinking agent for HDPE. The efficiency of the HDPE crosslinking with each peroxy derivative was analyzed on the basis of the behavior of the radicals generated from it. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 75–81, 2004     

Water‐swelling elastomer prepared by in situ formed lithium acrylate in chlorinated polyethylene

Lithium acrylate (LiAA) was in situ prepared in a chlorinated polyethylene (CPE) matrix through the neutralization of lithium hydroxide (LiOH) and acrylic acid (AA) during mixing. The obtained compounds were vulcanized with dicumyl peroxide (DCP). The in situ preparation and polymerization of LiAA were characterized with Fourier transform infrared spectrometry. The crosslink density analysis results indicated that the CPE/LiAA vulcanizates contained both covalent bonds and ionic bonds. The effects of the DCP and LiAA contents on the mechanical properties and water‐swelling properties of the CPE/LiAA vulcanizates were studied. The relationship between the LiOH/AA molar ratio and the properties of the CPE/LiAA vulcanizates was investigated. The results showed that LiAA could improve the mechanical and water‐swelling properties of CPE/LiAA vulcanizates, providing a new approach to the preparation of water‐swelling elastomers. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1804–1812, 2004     

Interfacial adhesion reaction of polyethylene and starch blends using maleated polyethylene reactive compatibilizer

The interfacial reaction of the polyethylene (PE)/starch blend system containing the reactive compatibilizer maleated polyethylene (m‐PE) was directly characterized by Fourier transform infrared (FTIR) spectroscopy. A significant amount of anhydride groups on m‐PE existed as hydrolyzed forms, resulting in a large amount of carboxyl groups. Using a vacuum‐heating‐cell designed in the laboratory, the carboxyl groups were successfully transformed into the dehydrolyzed state (i.e., anhydride group). This result enabled the direct spectroscopic observation of chemical reaction occurring at the interface. For the PE/starch blend system containing m‐PE, the chemical reaction at the interface was verified by the evolution of ester and carboxyl groups in the FTIR spectra. The effect of the reactive compatibilizer on the interfacial morphology was also examined by scanning electron micrography (SEM). Enhanced interfacial adhesion was clearly observed for the blend system containing reactive compatibilizer. Tensile strengths of blend systems containing m‐PE also increased noticeably compared with the corresponding system without compatibilizer. A similar observation was made for the breaking elongation data. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 767–776, 2002