Experimental Research on Thermal-Oxidative Aging Performance of Polyethylene Pipe Under Hydrostatic Pressure

Abstract

Aging performance of polyethylene (PE) material from PE pipe under hydrostatic pressure was investigated by measuring its mechanical/chemical properties. Tensile test, thermogravimetric analysis (TGA), oxidation induction time (OIT), as well as hardness test were carried out to evaluate the aging status of polyethylene material. Results show that as aging time prolongs, elongation rate after brake, thermal decomposition temperature, as well as oxidation induction time of PE specimen decrease, while its hardness increases, indicating that its mechanical/chemical properties change with the aging intensity. Life prediction model was also established based on failure time–pressure data obtained from hydrostatic pressure test, under the guidance of Arrhenius theory. Conclusions drawn from this research could help to prompt the efficiency of PE pipe on-site inspection as well as serve as references for understanding the aging behavior of PE pipe.