Comparison of the Notched Impact Strength at –30 °C of Polyethylene Grades with the Test Performance Behavior of Packagings for the Transport of Dangerous Goods

The notched impact strength at -30 °C is one of the selected properties together with the corresponding test method and tolerances for a comparison of polyethylene grades of one design type in the procedural rule on suitability proof for alternative plastic resins used for packagings and intermediate bulk containers (IBCs) for the transport of dangerous goods.

The marginal drop heights determined with the drop test at -18 °C after pre-storage of the test samples with 55 % nitric acid at 40 °C are associated only partly with the notched impact strength at -30 °C. The Charpy method is only suitable to classify the grade in relation to toughness behavior and use this classification for comparison with other grades. Notched impact strength can provide a qualitative indication if the test samples fail under shock loading.

Conditioning the design types with 55 % nitric acid for 21 days at 40 °C causes an increase of the marginal drop heights of the design types in drop tests at ‑18 °C when compared with design types without pre-storage. Post-crosslinking of the grades due the acidic influence is associated with an increase in stiffness.