Degradation of sunlight exposure on the high-density polyethylene (HDPE) pipes for transportation of natural gases

High-density polyethylene pipes are prevailing in transportation of combustible natural gases, so their reliability deserves special attention. Amongst the diverse ageing effects that are usually taken into account, including internal pressure, chemicals, temperature and vibration etc., the effect of sunlight exposure has been seldom concerned because the natural weathering test takes a really long time. Though the Xenon arc lamp is always used to simulate the ultraviolet environment, the natural weathering test is still the optimum to evaluate the performances degradation of materials to simulate the actual service conditions. In this paper, such a natural weathering test with sunlight exposure time up to 24 months was performed on the PE100 class high-density polyethylene pipes. The mechanical and the chemical properties before and after the test were measured to evaluate the extent and trend of degradation, and particularly the Fourier transform infrared microscope was utilized to quantitatively investigate the oxidation degradation mechanism in the microscopic level. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

The study conducted a long-term natural weathering test on PE100 class high-density polyethylene pipes exposed to sunlight for up to 24 months, investigating the aging process and mechanism. The results showed that the natural weathering test is the optimal method for evaluating material performance degradation.