The aim of this project was to study the efficacy of current methods of quality control and quality assurance for ultra-high molecular weight polyethylene (UHMWPE) products, and find improvements where possible. Intrinsic viscosity (IV) tests were performed on three grades of polyethylene with weight average relative molar masses $\bar{M}$ _w of about 6 × 10⁵, 5.0 × 10⁶ and 9.0 × 10⁶. Results from three laboratories showed substantial scatter, probably because different methods were used to make and test solutions. Tensile tests were carried out to 600 % extension at 150 °C under both constant applied load and constant Hencky strain rate, on compression mouldings made by a leading manufacturer of ultra-high molecular weight polyethylene. They gave low values of $\bar{M}$ _w, suggesting incomplete entanglement at ‘grain boundaries’ between powder particles. Results from conventional melt-rheology tests are presented, and their relevance to quality control and assurance is discussed. Attempts to calculate molecular weights from these data met with limited success because of extended relaxation times. Suggestions are made for improving international standards for IV testing of UHMWPE, by investigating the various factors that can cause significant errors, and by introducing methods for checking the homogeneity (and hence validity) of the solutions tested. Part 2 addresses characterization of crystallinity and structure. Part 3 covers mechanical properties, and Part 4 focuses on the sporadic crack propagation behaviour exhibited by all three grades of UHMWPE in fatigue tests on 10 mm thick compact tension specimens.

中文翻译：

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超高分子量聚乙烯的结构，加工和性能（IUPAC技术报告）。第1部分：表征分子量

该项目的目的是研究超高分子量聚乙烯（UHMWPE）产品当前质量控制和质量保证方法的功效，并在可能的情况下寻求改进。特性粘度（IV）测试是对三种等级的聚乙烯进行的，该三种聚乙烯的重均相对摩尔质量为$\overline{\mathrm{中号}}$ _瓦特的大约6×10 ⁵，5.0×10 ⁶和9.0×10 ⁶。三个实验室的结果显示出很大的分散性，可能是因为使用了不同的方法来制备和测试溶液。由领先的超高分子量聚乙烯制造商制造的压缩成型件在恒定施加载荷和恒定Hencky应变率的条件下，在150°C下进行了拉伸试验，拉伸至600％。他们给了低价值$\overline{\mathrm{中号}}$ _w，表明粉末颗粒之间“晶粒边界”处的缠结不完全。介绍了常规熔体流变测试的结果，并讨论了它们与质量控制和保证的关系。由于延长的弛豫时间，从这些数据计算分子量的尝试取得了有限的成功。通过研究可能导致重大错误的各种因素，并介绍了检查所测试溶液的均质性（以及有效性）的方法，提出了改进UHMWPE IV测试国际标准的建议。第2部分介绍了结晶度和结构的表征。第3部分介绍了机械性能，第4部分重点介绍了在10 mm厚的致密拉伸试样的疲劳测试中，所有三个等级的UHMWPE所表现出的零星裂纹扩展行为。