PE100级管材专用树脂的性能

采用凝胶渗透色谱仪、毛细管流变仪、电子万能试验机等研究了压力管材专用高密度聚乙烯树脂PN049-030-122的相对分子质量及其分布、流变性能及力学性能,并与国产同类树脂进行对比。结果表明:PN049-030-122具有较宽的相对分子质量分布,良好的加工性能、韧性、抗氧化性、拉伸性能;其管材制品在80℃,0.92 MPa下破坏时间大于500 h,达到PE100级。     

PE100级管材专用树脂性能研究

分析了高密度聚乙烯(HDPE)管材专用树脂DGDB 2480H及典型双峰PE 100级管材专用树脂的性能。两者的力学性能相当;DGDB 2480H具有较低的剪切黏度,有利于管材的加工成型,熔体强度为1.05 MPa,与国产及进口管材专用树脂相当,比普通HDPE大,有利于大口径管材的挤出。     

PE100级管材专用树脂的性能研究

中沙(天津)石化有限公司生产的管材专用树脂PN049-030-122达到了PE100级管材专用树脂的等级认证。在对其进行结构分析的基础上,评价了管材专用树脂的性能,并与国内相关树脂进行对比。结果表明,PN049-030-122管材专用树脂的应力置信下限值为10.75MPa,其耐慢速裂纹增长性能超过500h,200℃氧化诱导期在173min左右,具有良好的加工性能,且该管材专用树脂的性能完全满足国内生产给水管材的要求。     

PE100级管材专用树脂的结构与性能

通过熔体流动速率、差示扫描量热法分析、力学性能以及管材静液压试验等研究了3种PE100级管材专用树脂的结构与性能。结果表明:3种树脂在200℃条件下的氧化诱导时间均大于120 min,耐热氧老化性能良好;GC100S的熔流比为26.3,结晶度为60.1%,冲击强度为58.49 kJ/m~2,在80℃,5.4 MPa条件下的短期静液压测试耐压时间为348 h,均较其他两个试样好,为管材专用树脂的质量提升提供了技术支持。     

PE100级管材专用树脂的结构和性能

对两种采用不同工艺生产的PE100级管材专用树脂(分别记作树脂A和树脂B)进行了结构剖析和管材加工性能评价。结果表明:与树脂A相比,树脂B的共聚单体含量少,重均分子量大,相对分子质量分布略窄,结晶度高,零剪切黏度高,熔体强度大;相同加工温度条件下,树脂A的加工流动性好,树脂B的抗熔垂性好;两种树脂所制管材的静液压强度、耐慢速裂纹增长性能与耐快速裂纹扩展性能均满足国家标准要求。     

PE 100级管材专用树脂的开发

介绍了PE100级管材专用树脂的开发历程及等级认证结果;研究了管材专用树脂的常规性能、加工性能及短期静液压强度。结果表明：开发的2种管材专用树脂的应力置信下限值分别为10．261MPa和10．446MPa．达到PE100级,两者的加工性能均好。DGDB 2480 HBK的耐慢速裂纹增长性能超过500h．短期静液压强度达到GB 15558．1～2003要求,可用于PE100级燃气管的生产。     

橙色管材专用PE100级树脂的开发

以通过PE100级认证的管材专用高密度聚乙烯(牌号为TUB121N3000)为基体,紫外光老化和热氧老化时间为核心评价指标,开发出性能优异的橙色管材专用PE100级树脂。结果表明:橙色母料2544或2029B用量为最小单位用量的2倍,受阻胺光稳定剂、紫外光吸收剂、复合抗氧剂质量比为2∶3∶4时,制备的橙色管材专用PE100级树脂的氧化诱导时间大于30 min,颜料分散级别小于2级,紫外光老化2 000 h后色差小于3,烘箱老化后断裂标称应变保留率大于50%。     

PE100级管材专用HDPE树脂的开发

采用 Innovenes 工艺,双环管淤浆法,1-已烯为共聚单体开发生产了 PE100级管材专用高密度聚乙烯(HDPE)树脂PN049-030-122,分析了其结构、力学性能及加工应用情况,并与国内外同类产品进行了对比.HDPEPN049-030-122的熔体流动速率为0.290～0.300 g/10 min,密度为0.949g/cm3,拉伸弹性模量达1 100 MPa以上,简支梁缺口冲击强度大于30 kJ/m2,各项性能达到指标要求,相对分子质量分布曲线呈双峰.     

双峰PE100级管材专用树脂的结构与性能北大核心

采用差示扫描量热法分析、核磁共振碳谱、连续自成核退火热分级、高压毛细管流变、旋转流变等研究了国内外三种PE100级管材专用双峰(即相对分子质量分布呈双峰)聚乙烯(PE)的结构与性能。结果表明:三种双峰PE片晶厚度分布指数接近,易形成较厚片晶;属于假塑性流体,剪切黏度对剪切速率变化敏感;熔体强度高,抗熔垂性能好,适宜高速挤出成型,制作大口径、尺寸稳定性产品。PE100级管材专用树脂P6006熔体强度和零剪切黏度较高,推断P6006相对分子质量高,且高相对分子质量部分含量高;3490LS剪切黏度对剪切速率变化最敏感,剪切变稀明显;3490LS相对分子质量分布较宽,具有较好的加工性能。     

PE100RC专用树脂流变性能研究

对PE100RC专用树脂1#、2#、3#、4#的剪切流变性能、熔体强度、动态流变性能等进行研究,研究表明:3#的分子量最大,1#与2#的分子量相同,4#的分子量最小。用同一条件挤出加工管材时,4#最不易破管,而3#最易破管。1#、2#、3#、4#为无长支链的线型分子。     

耐热聚乙烯管材专用树脂的结构与性能

研究了3种耐热聚乙烯管材专用树脂的结构与性能。它们的共同特征为熔体流动速率低于0.7 g/10 min,密度为0.930~0.944 g/cm3,相对分子质量为(1.5~2.5)×105,可以为窄相对分子质量分布,也可以为中等相对分子质量分布。1-己烯共聚产品与1-辛烯共聚产品性质较为接近,都是窄相对分子质量分布,而1-丁烯共聚产品具有相对分子质量高(2.0×105以上),相对分子质量分布中等(10左右),熔体流动速率低(低于0.3 g/10min)、密度高(大于0.940 g/cm3)、拉伸屈服强度高、弯曲模量高、熔融峰温高、结晶峰温高的特点。相同条件下,1-丁烯共聚产品具有较高的黏度和模量。     

PE树脂的流变行为与其结构性能的关系

综述了聚乙烯(PE)树脂的流变行为与其相对分子质量、相对分子质量分布、支化结构、加工性能、制品性能的关系,介绍了用流变手段及参数表征PE树脂分子结构的方法.建议加大PE树脂流变行为的研究力度,为PE树脂的产品开发与推广应用提供技术支持.     

Effect of the nature of the filler on rheological and rheokinetic properties of composites based on epoxy resins

Conclusions The viscosity properties of epoxy resins in the presence of fillers of various nature have been investigated; the effect of various factors on the kinetics of hardening of compositions by polyethylenepolyamide has also been studied.A decisive role of the form anisotropy of the filler particles in manifestion of viscosity anomaly effects and of thixotropy has been shown.A tendency toward retardation of the epoxy resin hardening process in the presence of finely cut up carbon fibres has been detected.Translated from Khimicheskie Volokna, No. 3, pp. 36–37, May–June, 1988.     

Thermal and rheological properties of poly(phenylene sulfide) and poly(ether etherketone) resins and composites

Poly(phenylene sulfide) (PPS) and poly(ether etherketone) (PEEK) are high performance engineering thermoplastics with a unique combination of excellent environmental, mechanical, and thermal properties. Research on the thermal and rheological properties of PPS and PEEK resins and carbon fiber reinforced prepregs are described. Experimental studies of the dynamic viscoelasticity and thermal properties of these materials are summarized. The effects of processing cycles and environment on the thermal and rheological properties are discussed. The effects of the processing environment and the addition of carbon fiber on the thermal stability are reported. Crosslinking of poly(phenylene sulfide) in air, enhancing thermal stability, is also investigated.     

Effect of PVC resins on multi-screw pipe extrusion

The increased use of multi-screw (twin) extruders by pipe producers brought on this study of available PVC homopolymer “pipe grade” resins. Basic tests on resin were examined via a “Correlation Matrix” computer program. Highly significant test data were determined to be internal pore volume and centrifuge plasticizer adsorption. Additional compound evaluation proceeded via torque rheometer followed by twin-screw extrusion. Significant resin test values affecting extrusion properties are inherent viscosity, apparent bulk density, porosity uniformity and melt viscosity. The work shows that the compounder should know resin properties in order to benefit from processing equipment developments.     

Fracture and mechanical properties of epoxy resins and rubber-modified epoxy resins

Fracture and mechanical property data on a wide range of epoxy resin systems are presented. The extent to which toughening can be induced by heterophase rubber inclusions depends more on the curing agent used than on the resin component. The greatest improvements in toughness were obtained by rubber modification of epoxy resins cured with an anhydride. A preformed ABS polymer can be used to toughen many epoxy resin systems. With one major exception (where a large improvement was found) only small changes in tensile properties occur when small amounts of rubber are present.     

Composition and surface energy characteristics of new petroleum resins

We investigated the composition and surface energy properties—the surface free energy, acid–base and dispersive components, acid and base parameters (according to the van Oss–Chaudhury–Good method) and acidity parameter (according to the Berger method) for several types of aromatic petroleum resins (PR). We could see that the Berger, nonlinear systems, and spatial methods provide slightly different information about the acid–base properties of PRs. For acid–base properties, relevant proton content was determined for each sample by nuclear magnetic resonance spectroscopy. Correlations between the composition and surface characteristics of the studied aromatic PR have been revealed. According to the data obtained from the acid–base approach and nuclear magnetic resonance spectroscopy, we can predict the possible combinations of PR–polymer with the best interface interaction, which can lead to high mechanical properties. POLYM. ENG. SCI., 57:1028–1032, 2017. © 2016 Society of Plastics Engineers     

Investigation of cure in epoxy acrylate resins using rheological and dielectric measurements

Dielectric and rheological measurements are reported for the cure in a series of mixtures of an epoxy-acrylate with n-butyl methacrylate. The level of the initiator and properties of the epoxy acrylate and n-butyl methacrylate influence the cure characteristics and morphology of the film formed. Analysis of the rheological data indicates that during the curing process, microphase separation occurs within the mixture. The changes in the dielectric relaxation behavior with composition of the completely cured material is also consistent with microphase separation occurring in these resins while they are cured.     

Splitting for strength: Manipulating polymerization reactor split ratios to control mechanical and rheological properties in bimodal polyethylene resins

This study integrates advanced mathematical modeling and experimental methodologies to investigate the simultaneous impact of modifications in the split ratio and molecular weight (MW) of chains on the rheological and mechanical properties of bimodal polyethylene (BiPE) resins. The outcomes underscored the viability of fine-tuning the molecular weight distribution (MWD) of a BiPE resin by augmenting the MW of high molecular weight (HMW) chains while simultaneously diminishing their proportion in the final alloy formulation. In addition, the experimental results illuminated the prospect of attaining a targeted melt flow index for the final polymers by elevating the MW of HMW chains alongside an increase in the proportion of low molecular weight chains. Significantly, these adjustments resulted in remarkable enhancements in the shear thinning index and strain hardening modulus of the fabricated resins.