Abstract High-Density Polyethylene is prone to Environmental Stress Cracking if mechanically stressed in the presence of solutions containing surfactants. Even if this polymer is widely used to produce containers for industrial and household detergents, its Environmental Stress Cracking Resistance is generally evaluated under plane strain conditions irrespective of the actual stress state experienced during service life. In this work the Slow Crack Growth of thin specimens, under plane stress conditions, was studied in air and in the presence of an “active” environment. The J -integral approach was adopted to account for the extensive plastic deformations thereby occurring and the obtained results were compared to those describing the plane strain behaviour of the same polyethylene, reported in previous works. The effect of the production process was also assessed by comparing the behaviour of compression moulded and blow moulded specimens, the latter having a lower degree of crystallinity. Despite the difference in fracture resistance expected in air, the behaviour in presence of the active environment was very similar, suggesting that the production process has only negligible influence on the Environmental Stress Cracking resistance of the considered polyethylene.

中文翻译：

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平面应力条件下高密度聚乙烯的环境应力开裂

摘要 如果在含有表面活性剂的溶液中受到机械应力，高密度聚乙烯容易发生环境应力开裂。即使这种聚合物被广泛用于生产工业和家用洗涤剂的容器，它的耐环境应力开裂性通常在平面应变条件下进行评估，而与使用寿命期间经历的实际应力状态无关。在这项工作中，研究了在空气中和存在“活跃”环境的情况下，在平面应力条件下薄试样的缓慢裂纹扩展。采用 J 积分方法来解释由此发生的广泛塑性变形，并将获得的结果与描述相同聚乙烯的平面应变行为的结果进行比较，在以前的工作中报道。还通过比较压塑和吹塑样品的行为来评估生产过程的影响，后者具有较低的结晶度。尽管在空气中预期抗裂性存在差异，但在活性环境存在下的行为非常相似，这表明生产过程对所考虑的聚乙烯的环境应力开裂抗性的影响可以忽略不计。