Effect of climatic ageing on extra long-term fracture mechanical properties of polyethylene

摘要

The change of fracture resistance of medium density polyethylene (MDPE) has been studied over a wide time interval using SEN- T specimens. Employing first-level sampling (FLS) method, time dependence of the fracture toughness (K_Q) was revealed in 2.6 × 10~5 h (～30 years) interval. Based on the measured data, time-related fracture mechanical properties were determined, that characterise the long-term fracture behaviour of polyethylene. Using infrared spectroscopy (IR), a relationship was detected between the change of fracture mechanical properties and the oxidative degradation of polyethylene. The results are applicable for long-term fracture mechanical design of polyethylene.