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。     

交联聚乙烯绝缘料用基础树脂的性能研究

利用拉伸试验、红外光谱、凝胶渗透色谱、差示扫描量热法、流变表征等方法测试了交联聚乙烯绝缘料用基础树脂的性能,并研究了制备硅烷交联和过氧化物交联聚乙烯绝缘料的基础树脂组成。结果表明,交联聚乙烯绝缘料用LDPE树脂的基本性能:MFR为2.0g/10 min,密度为0.920g/cm3,熔点为107℃左右,拉伸强度大于12MPa,断裂伸长率大于580%,介电常数小于2.3,相对支化度2.34左右。硅烷交联聚乙烯绝缘料宜用LLDPE和LDPE的共混物做基础树脂,而过氧化物交联聚乙烯绝缘料的基础树脂用LDPE即可。     

硅烷交联聚乙烯电缆绝缘料的研制

本文介绍了硅烷交联聚乙烯（ＸＬＰＥ）生产技术、材料选择及用量对电缆料性能的影响，探讨了温度等对凝胶率的影响，用两步法工艺研制了硅烷接枝温水交联聚乙烯电缆绝缘料。     

改性聚乙烯的制备工艺及其在体育器材领域的应用研究进展

综述了聚乙烯交联改性方法,包括过氧化物交联法、辐照交联法和硅烷交联法等,并分析了各类方法的优势和弊端。采用二步法硅烷交联工艺制备改性聚乙烯,解决了过氧化物交联法、辐照交联法存在控制难度较高,投资大等问题,通过添加过氧化二异丙苯,可以显著降低改性聚乙烯生产成本,提高综合应用。此外,还概括了改性聚乙烯在体育器材领域的应用。     

紫外光与硅烷交联对聚乙烯电缆材料性能的影响

以线型低密度聚乙烯(LLDPE)为基体树脂,分别制备出紫外光交联与硅烷交联电缆用绝缘料。讨论了两种交联方法对聚乙烯绝缘材料性能的影响。结果表明:对于无色母填充的聚乙烯材料,紫外光交联后的样品在凝胶含量、热收缩、耐老化及电性能等方面均明显优于硅烷交联聚乙烯材料。     

交联聚乙烯开发应用与发展建议

综述了各种交联聚乙烯的生产技术，包括辐射交联、过氧化物交联、硅烷交联、紫外光交联、盐交联等交联方法。同时对交联聚乙烯在电线电缆、管材等领域的应用提出了我国发展交联聚乙烯的建议。     

LDPE 2102 TN 00在交联电缆绝缘料中的应用

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2102 TN 00等几种低密度聚乙烯的性能进行了测试,并以2102 TN 00为基础树脂分别制备了硅烷交联和过氧化物交联聚乙烯电缆料。结果表明,2102 TN 00适合做聚乙烯交联电力电缆绝缘料的基础树脂。     

绝缘材料用交联聚乙烯的研发进展

综述了绝缘材料用交联聚乙烯的研发进展。采用过氧化物化学交联法,通过添加纳米聚合物可以提高交联聚乙烯的电荷输运调控能力和击穿场强,从而提升交联聚乙烯绝缘材料的耐高压交流击穿能力;通过添加电压稳定剂可以改善交联聚乙烯绝缘材料的耐电性能和击穿强度;通过添加含磷助剂和含氮助剂可以提升交联聚乙烯电缆绝缘材料的高压直流击穿强度以及抑制空间电荷性能。采用硅烷交联法,添加长诱导时间催化剂母粒生产的绝缘材料抗老化并且诱导时间可控,在生产和使用过程中不发生预交联,生产过程中炭黑的均匀分散有助于中低压架空电线电缆耐气候性能的提升。     

硅烷交联聚乙烯电缆绝缘料的生产工艺

介绍了一种生产硅烷交联聚乙烯电缆绝缘料的新工艺,此工艺生产的材料具有良好的综合性能。与 其他工艺相比,此工艺简单、生产效率高、成本低。     

硅烷交联聚乙烯电力电缆绝缘料的研制

采用两步法制备了硅烷交联聚乙烯（PE）电力电缆绝缘料。以双螺杆挤出机为反应器,以低密度聚乙烯（LDPE）和线型低密度聚乙烯（LLDPE）为基础树脂,考察了影响PE接枝交联的主要因素（如基础树脂的配比,交联剂的用量及种类,引发剂、抗氧剂的用量等）,得出了具有良好性能的硅烷交联PE电力电缆绝缘料的配方（质量份数）：LDPE为85．00phr,LLDPE为15．0H0phr,硅烷W为0．60phr,硅烷Q为1．40phr,引发剂为0．12phr,抗氧剂为0．20phr。     

Preparation of Silane-Grafted and Moisture Crosslinked Low Density Polyethylene. Part II: Electrical,Thermal and Mechanical Properties

Among different polyethylene cross-linking methods, such as peroxide, irradiation, and silane cross-linking, silane-based methods are the most suitable methods for producing cable insulation and hot water pipe materials due to process simplicity and superior properties of its product. Some electrical, thermal and mechanical properties of silane-grafted water-cross-linked polyethylene were investigated. The effects of silane grafting and gel content on volume resistivity, tensile properties and melting behavior of low density polyethylene (LDPE) were studied. Results indicated that volume resistivity increased with increasing gel content. Stress at break increased with increasing grafting level and gel content. Elongation at break increased with grafting and decreased with gel content. High temperature tensile properties showed that cross-linked polyethylene (XLPE) is more stable than LDPE at high temperature. In differential scanning calorimetry (DSC) analysis a broad endothermic peak appeared for XLPE due to phase separation. Melting point and crystalline percentage decreased with increased grafting level and gel content. Incorporation of carbon black into XLPE reduced the volume resistivity and degree of crystallization.     

聚乙烯交联改性研究进展

综述了近年来国内外对聚乙烯交联技术（辐射交联、过氧化物交联、硅烷交联）的研究进展情况，同时介绍了3种主要交联方法的反应机理和优缺点。     

Effect of silane‐grafting on water tree resistance of XLPE cable insulation

Water treeing is one of the main deterioration phenomena observed in the polymeric insulation of extruded crosslinked polyethylene (XLPE) cables, which can affect the service life of power cables. In this work, we investigated the effect of grafting of a silane (vinyl trimethoxysilane, VTMS) on the resistance of XLPE to water treeing. A series of water‐treeing tests, the mechanical and dielectric measurements indicated that the silane‐grafting could significantly improve the water tree resistance of the conventional XLPE cable insulation with little influences on its dielectric properties, e.g., the dielectric breakdown strength, dielectric constant and loss tangent, and its mechanical performance. It was found that there exists an optimum value of VTMS concentration (about 0.6 phr) corresponding to the minimum water tree length. The water tree resistance mechanism of silane‐grafted XLPE was proposed on the basis of the process of silane hydrolysis and crosslinking. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Preparation of Silane-Grafted and Moisture Cross-Linked Low Density Polyethylene: Part I: Factors Affecting Performance of Grafting and Cross-Linking

In the present work, the silane grafting and water cross-linking of low density polyethylene (LDPE) were investigated. The grafting reaction was carried out in an internal mixer and polyethylene cross-linking was done in hot water. The effect of silane, peroxide, catalyst, carbon black, cross-linking time, and cross-linking temperature on the grafting and cross-linking processes are reported. Vinyl trimethoxy silane (VTMO) and di-cumyl peroxide (DCP) were selected as grafting agent and initiator respectively. Silane grafting on polyethylene was determined using Fourier transform infrared (FTIR) spectroscopy and torque monitoring of the mixer. Absorption peak due to –Si–OCH₃ groups in FTIR and torque increasing due to silane grafting in the mixer illustrated that silane-grafting reactions occurred. The FTIR data demonstrated that the extent of silane grafting was increased as the concentration of silane and peroxide was increased. Thermogravimetry analysis (TGA) determined that the thermal stability of LDPE increased by increasing the amount of silane grafting. Gel fraction increased with silane and peroxide concentration. As the percent of of catalyst increase the time scale for specified gel content shifted to shorter times. Incorporation of carbon black into LDPE decreased the extent of silane grafting and gel fraction. Water temperature increasing in cross-linking stage reduced the time to maximum degree of cross-linking.     

Oxidation induction time correlations with radiation dose and antioxidant concentration in EPR and XLPE polymers

Oxidation induction time (OIT), as measured by differential scanning calorimetry, is useful in assessing the extent of degradation in polymeric materials. Values of OIT for typical EPR and XLPE polymer insulation materials used for electric cable insulation in nuclear power plants were measured as a function of both radiation dose and antioxidant concentration after accelerated aging. Irradiations were performed at the University of Virginia Cobalt Irradiation Facility. OIT was found to decrease exponentially with increasing radiation dose and with decreasing antioxidant concentration for both ethylene-propylene rubber (EPR) and cross-linked polyethylene (XLPE) insulations. It was determined experimentally that, when polymers are subjected to a constant radiation dose rate, antioxidant concentration decreases linearly with time, and it was shown that this variation is consistent with theoretical autoxidation kinetics. © 1993 John Wiley & Sons, Inc.     

废弃交联PE的力化学再生及其与PE-HD共混物性能的研究

采用固相力化学技术,实现了交联聚乙烯电缆料（XLPE）的力化学回收。结果表明：固相力化学方法是实现XLPE热塑性加工的有效手段,经力化学处理后,再生XLPE的拉伸强度为13.7 MPa,断裂伸长率为383 ％。XLPE经力化学处理后表观黏度下降,加工流动性显著改善。将力化学处理的XLPE与高密度聚乙烯(PE-HD)共混,加工性能进一步得到改善,XLPE/PE-HD共混材料的拉伸强度和断裂伸长率分别达到18.5 MPa和500 %。XLPE/PE-HD共混物的SEM断面形貌分析表明,力化学处理可有效改善共混体系中XLPE和PE-HD的相容性。     

Comparison of oxidation induction time measurements with values derived from oxidation induction temperature measurements for EPDM and XLPE polymers

Oxidative stability and retained operational utility of polymers used as insulation for electrical cables, such as ethylene propylene diene monomer (EPDM) and crosslinked polyethylene (XLPE), may be assessed by oxidation induction time (OIT) analysis. OIT is measured directly with a differential scanning calorimeter. Using a simplified kinetics model, Gimzewski demonstrated that it is possible to calculate the OIT from measured values of oxidation induction temperature and the activation energy for petroleum lubricants. In the present research, directly measured OITs are compared with OITs calculated from measured oxidation induction temperatures and activation energies for EPDM and XLPE cable insulation. Good agreement between the two methods was demonstrated for these materials.     

Assessment of oxidative thermal degradation of crosslinked polyethylene and ethylene propylene rubber cable insulation

This paper presents procedures to monitor oxidation degradation of two commonly used cable insulations, crosslinked polyethylene (XLPE) and ethylene propylene rubber (EPR). Since the techniques described require only micro specimens, deterioration of cable insulation can be monitored without destroying the function of the cable. The techniques described are melting point, crystallinity, infrared carbonyl absorbance, gel content, relative hardness, and differential scanning calorimetry (DSC) oxidation induction time. The techniques were applied following accelerated aging over a period in excess of two years. The results from the micro specimens were directly related to embrittlement and the decrease in ultimate elongation. The previous thermal history of XLPE was determined using DSC melting peak analysis.