Abstract The alteration in lifetime relevant material characteristics, such as slow crack growth (SCG) resistance, of a virgin PE-HD pipe grade (PE80) with successively increasing amounts of a virgin PP block copolymer (PP-B) was studied in frame of this research. For this purpose, Cyclic Crack Round Bar (CRB) tests were performed, demonstrating the high negative impact of an already small amount of polymeric impurity, which leads to a significant reduction of the SCG resistance. Already 5% mixing content evokes a dramatic decrease of SCG resistances of up to 40 and 70 % for PE-HD and PP-B, respectively. As SCG is generally accepted to be a critical failure mechanism for plastics used in long-term applications, such as pipes, this effect must be carefully considered in all discussions about the use of nonvirgin polymers.

中文翻译：

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聚乙烯和聚丙烯交叉污染对缓慢裂纹扩展阻力的影响

摘要 在以下框架内研究了原始 PE-HD 管道等级 (PE80) 与连续增加数量的原始 PP 嵌段共聚物 (PP-B) 的寿命相关材料特性的变化，例如抗慢速裂纹扩展 (SCG)。这项研究。为此，我们进行了循环裂纹圆棒 (CRB) 测试，证明了少量聚合物杂质的严重负面影响，导致 SCG 抗性显着降低。对于 PE-HD 和 PP-B，已经 5% 的混合含量引起了 SCG 电阻的显着降低，分别高达 40% 和 70%。由于 SCG 被普遍认为是长期应用（例如管道）中使用的塑料的关键失效机制，因此在所有关于使用非原生聚合物的讨论中必须仔细考虑这种影响。