HDPE／LLDPE／EVA共混物的研究

本文用高密度聚乙烯（ＨＤＰＥ）为主体材料，选择线性低密度聚乙烯（ＬＬＤＰＥ）和乙烯－醋酸乙烯酯共聚物（ＥＶＡ）为改性剂，制备了ＨＤＰＥ／ＬＬＤＰＥ／ＥＶＡ共混物。分析了改性剂对共混体系力学强度的影响，研究了共混组分的相容性以及共混物的韧性和挤出加工性能。     

改性高密度聚乙烯管材料的研究

本文以国产高密度聚乙烯（ＨＤＰＥ）为基础树脂，线性低密度聚乙烯（ＬＬＤＰＥ）为改性剂，采用共混改性的方法研制了保温管外套管材料。对ＬＬＤＰＥ的含量对拉伸强度，断裂伸长率等力学性能的影响进行了实验研究。通过动态力学试验结果和透射电镜观察，分析了材料韧性与耐环境应力开裂性能之间的关系。     

改性高密度聚乙烯管材料的研究

本文以国产高密度聚乙烯（ＨＤＰＥ）为基础树脂，线性低密度聚乙烯（ＬＬＤＰＥ）为改性剂，采用共混改性的方法研制了保温管外套管材料。对ＬＬＤＰＥ的含量对拉伸强度、断裂伸长率等力学性能的影响进行了实验研究。通过动态力学试验结果和透射电镜观察，分析了材料韧性与耐环境应力开裂性能之间的关系。     

聚丙烯／高密度聚乙烯／乙丙橡胶共混体系的研究

本文研究了聚内烯／高密度聚乙烯／乙丙橡胶共混体系中高密度乙烯（ＨＤＰＥ）和乙丙橡胶（ＥＰＤＭ）对聚丙烯（ＰＰ）的力学性能的影响规律。实验结果表明,加入ＥＰＤＭ可以改变ＰＰ的结晶度与球晶结构,有利于应力的平均分布,使其冲击强度得到提高。而ＨＤＰＥ作为第三相,可以改善ＰＰ与ＥＰＤＭ之间的相界面结构,增加体系的相容性。     

高速挤出LLDPE绝缘料加工性能的研究

线性低密聚乙烯（ＬＬＤＰＥ）的挤出加工性能差，通过对ＬＬＤＰＥ树脂共混改性，并加入研制的特种润滑母料，可改善ＬＬＤＰＥ的挤出加工性能，使之达到通信电缆聚乙烯绝缘料高速挤出的要求。     

DH485网─NOVELL网互连与实时通信技术

介绍了基于美国Ａ─Ｂ公司ＳＬＣ５００系列可编程序控制器的ＤＨ４８５工业局域网（简称ＤＨ４８５网）及ＮＯＶＥＬＬ计算机局域网（简称ＮＯＶＥＬＬ网），着重讨论了ＤＨ４８５网与ＮＯＶＥＬＬ网的实时通信技术，并对这两个异型网的互连及实时通信作了进一步探讨。     

DH485网—NOVELL网互连与实时通信技术

介绍了基于美国Ａ－Ｂ公司ＳＬＣＴ５００系列可编程序控制器的ＤＨ４８５工业局域网（简称ＤＨ４８５网）及ＮＯＶＥＬＬ计算机局域网（简称ＮＯＶＥＬＬ网），着重讨论了ＤＨ４８５网与ＮＯＶＥＬＬ网的实时通信技术，并对这两个异型网的互连及实时通信作了进一步探讨。     

CR／CPE电缆护套料的研制

采用氯丁橡胶（ＣＲ）作电缆护套材料时，共混一定量的氯化聚乙烯（ＣＰＥ）可明显改善共混物的耐热性，提高其定伸强度，拉伸强度及撕裂强度，且在一定程度上可降低生产成本。ＣＲ／ＣＰＥ用量比及硫化体系的选择是ＣＲ／ＣＰＥ电缆护套科研制的关键，试验表明：ＣＲ／ＣＰＥ用量比为７０／３０～６０／４０之间，选用Ｎａ－２２／ＤＰＴＴ并用作硫化体系时，电缆护套料的性能较好，符合ＧＢ７５９４、ＧＢ９３３１标准要求。     

CR／CPE电缆护套料的研制

采用氯丁橡胶（ＣＲ）作电缆护套材料时，共混一定量的氯化聚乙烯（ＣＰＥ）可明显改善共混物的耐热性，提高其定伸强度，拉伸强度及撕裂强度，且在一定程度上可降低生产成本。ＣＲ／ＣＰＥ用量化及硫化体系的选择是ＣＲ／ＣＰＥ电缆护套料研制的关键。试验表明：ＣＲ／ＣＰＥ用量比为７０／３０～６０／４０之间，选用Ｎａ－２２／ＤＰＴＴ并用作硫化体系时，电缆护套料的性能较好，符合ＧＢ７５９４ＧＢ９３３１标准要求。     

电缆绝缘用低密度聚乙烯与乙烯醋酸乙烯共聚物的共混

研究了耐热电缆绝缘用ＥＶＡ（ＶＡ含量２８％）与ＬＤＰＥ的共混，以及这些共混物的电气、机械和热性能。这些共混物作为绝缘材料，其额定温度约为１２０～１３５Ｃ°，介于以三元乙丙胶为基的耐热绝缘（额定温度为８５～９０Ｃ°）和以硅橡胶为基的耐高热绝缘（额定温度为１５０Ｃ°）之间。     

利用锥形量热仪评价EVA/Mg(OH)2基阻燃电缆料

介绍了利用锥形量热仪(CONE)分析和研究乙烯-醋酸乙烯共聚物(EVA)与Mg(OH)2和硅树脂共混的电缆阻燃料的各种阻燃特性,论证了EVA混入了Mg(OH)2和硅树脂后,其阻燃特性有了很大的提高,并证实了采用CONE可克服和改善氧指数法测量材料阻燃特性所存在的氧指数测量值与成品电缆燃烧试验结果相关性不足的缺点。     

125°C辐照交联低烟无卤阻燃聚烯烃电缆料的开发研究

介绍了125°C辐照交联低烟无卤阻燃聚烯烃电缆料的特殊性能,研究了基料的选用及共混;相容剂、阻燃体系、抗氧体系、加工助剂等的选用对材料性能的影响,结果表明,采用EVA与HDPE共混体系或者选用EPDM与EVA共混体系,使用本公司自制的相容剂,及采用Al(OH)3/Mg(OH)2/阻燃剂A和Al(OH)3/Mg(OH)2/阻燃剂A/阻燃剂B的阻燃体系,采用抗氧剂A/抗氧剂D可以成功地生产出性能优异的无卤材料,在机械性能、耐高温性能、阻燃性能、低烟无毒性能、加工性能方面与美国联碳DFDA-1472NT相当。     

Assessment of dielectric behavior of recycled/virgin high density polyethylene blends

In this work, high density polyethylene (HDPE) incorporation in virgin resin was assessed as to its electrical performance with the use of volumetric resistivity, dielectric strength, and stress tracking measurements. HDPE post-consumer packaging was collected and submitted to a basic process of plastic recovering: washing, grinding, and drying. Formulations containing 0, 25, 50, 75, and 100% of recycled material in the virgin resin were reprocessed by extrusion and injection molding with stabilization. Dielectric strength test results were analyzed by the statistical distribution of Weibull, and the maximum likelihood method. The degree of crystallinity was measured by X-ray diffraction. Atomic absorption spectroscopy was also done to identify metallic residue present in the samples. From the results analyzed, it can be concluded that the HDPE derived from post-consumer packaging can be considered in electrical insulation systems for low voltage (up to 600 V) containing as much as 75% incorporated virgin resin.     

三聚氰胺氰尿酸盐协效氢氧化镁阻燃乙烯-醋酸乙烯酯共聚物的性能研究

以EVA为基体树脂,硅烷偶联剂KH-550改性氢氧化镁(MH)为主阻燃剂,三聚氰胺氰尿酸盐(MCA)为协效阻燃剂,添加相容剂MC328,制备了EVA复合材料,研究和对比了MCA、MC328含量对复合材料的力学性能、加工性能、燃烧、极限氧指数等性能的影响.结果表明:MCA的加入改善了体系力学性能及加工性能,提高了燃烧性能...     

Charge distribution in polyethylene/ethylene vinylacetate laminatesand blends

The formation of space charge in polyethylene/ethylene vinylacetate copolymer (PE/EVA) laminates was investigated using a pulsed electroacoustic (PEA) method. The formation of heterocharge was observed in PE while positive charge (holes) was distributed over the EVA specimen. In the laminates, however, a large amount of charge accumulates at the interface between PE and EVA, resulting in an increase of the electric field in the PE layer. When the thickness of the EVA layer is smaller than that of the PE layer, negative charge dominates in the PE layer due to enhanced charge injection caused by the increased electric field in the PE layers. When these polymers are blended, the amount of heterocharge in the PE/EVA blends varies inversely with the vinylacetate content by the enhancement of homocharge trapping at PE/EVA interfaces and/or by the enhancement of charge injection via an increased electric field in the PE component     

Interfacial charge in polyethylene/ethylene vinylacetate laminates

Space charge formation in polyethylene (PE)/ethylene vinylacetate copolymer (EVA) laminates has been investigated using a pulsed electroacoustic method. The PE shows heterocharge while the EVA shows a broad distribution of positive charge over the sample. The positive charge in EVA decreases with the increase of vinylacetate (VA) content in EVA. Interfacial charge is found in all laminates and remains unchanged by heat treatment at 100°C to 1 h and by coating chemicals such as silicone oil and trimethylolpropane trimethacrylate at the interfaces, This interfacial charge distorts the electric field distribution in the direction of increasing the electric field in the PE layers. The charge distribution in PE/EVA blends has been measured and is explained via the results obtained with the laminates     

固化程度对氰酸酯-酚醛环氧树脂共混物热/湿热性能的影响

论文研究了具有不同固化程度的双酚A二氰酸酯-酚醛环氧树脂共混物的Ts转变和后固化过程中Ts转变的变化以及共混物的吸湿规律和湿热老化对共混物结构的影响。结果表明，固化程度可显著影响固化物的Ts和后固化过程中剩余反应的温度。表观转化率提高，则吸湿性降低；固化程度越大，湿热老化对化学结构影响越小，但当固化转化率不高时(例如小于90％)，湿热老化可能对共混物结构产生显著影响。     

Electrical and environmental stress and the hydrophobic stabilityof SIR, EVA and their blends

This paper treats the effects of electrical and environmental stresses on the hydrophobicity of polymers intended for use in nonceramic insulators. We investigated the effect of UV radiation, corona discharges, dry-band arcing, acid rain and water absorption on hydrophobic transfers in, and the aging of, room temperature vulcanized (RTV)-silicone rubber (SIR), high temperature vulcanized (HTV)-silicone rubber (SIR), ethylene vinyl acetate (EVA) rubber and the blends made from HTV-SIR and EVA. Acid rain had little influence on hydrophobicity in any of the samples. EVA and the blends with low silicone ratios to EVA allowed much larger reduction in hydrophobicity after or while subjected to the above stresses (except for acid rain) than did the silicone rubbers and a blend with a high silicone ratio to EVA. Salt-fog tests were conducted to correlate the hydrophobic stabilities of materials with leakage current levels thereon. The hydrophobic stability of the silicone rubbers was attributed to low-molecular-weight silicone components that were able to migrate and finally cover the aged surface layers. Because EVA possessed less fluid components and less chemical stability under electrical and environmental stresses, its hydrophobicity was readily reduced and hardly recovered, which led to higher current leakage and early material aging. For each material, the critical hydrophobic level permitting leakage current to develop was determined by adding a non-ionic wetting agent to saline water     

聚丙烯/聚乙烯共混合金中聚乙烯的含量对性能的影响

为了改善作为绝缘通信埋地管材常用的塑料的力学性能，以聚丙烯为基本主体材料，加入一定量的高密度聚乙烯进行增韧改性后形成新的混合塑料体系，研究不同加入量的高密度聚乙烯对共混合金的各种力学性能的影响，讨论了HDPE在PP／HDPE体系中的加入量与材料的拉伸强度、伸长率、弯曲强度、冲击强度、硬度、耐热性等各力学性能之间的关系。结果表明在体系中加入25％的HDPE共混合金具有较好的综合力学性能。