With the widespread use of polyethylene(PE)materials in gas pipelines,the problem related to the aging of these pipes has attracted increasing attention.Especially under complex environmental conditions involving temp...With the widespread use of polyethylene(PE)materials in gas pipelines,the problem related to the aging of these pipes has attracted increasing attention.Especially under complex environmental conditions involving temperature,humidity,and pressure changes,PE pipes are prone to oxidative degradation,which adversely affects their performance and service life.This study investigates the aging behavior of PE pipes used for gas transport under the combined effects of temperature(ranging from 80℃to 110℃)and pressure(0,0.1,0.2,and 0.3 MPa).By assessing the characteristics and thermal stability of the aged pipes,relevant efforts are provided to explore the performance variations during the aging process and develop methods for evaluating thermal stability.The results indicate that an increase in aging factors,specifically temperature and pressure,significantly reduces theMeltMass Flow Rate(MFR)of polyethylene pipes,suggesting a decline in the material’s flowability during the aging process.Oxidative Induction Time(OIT)tests show that with increasing temperature and pressure,the oxidative induction time of the aged polyethylene pipes progressively shortens,indicating a significant reduction in the material’s oxidative stability.The application of the Arrhenius equation further demonstrates that the aging reaction rate of polyethylene pipes in high-temperature environments is closely related to both temperature and activation energy,thereby laying the foundation of a new approach for the development of an initial model that can reflect the microscopic behavior of polyethylene pipes in aging environments.展开更多
基金supported by the Sponsored by Natural Science Foundation of Xinjiang Uygur Autonomous Region(no.2022D01C389)the Xinjiang University Doctoral Start-up Foundation(no.620321029)the Science and Technology Planning Project of State Administration for Market Regulation(no.2022MK201).
文摘With the widespread use of polyethylene(PE)materials in gas pipelines,the problem related to the aging of these pipes has attracted increasing attention.Especially under complex environmental conditions involving temperature,humidity,and pressure changes,PE pipes are prone to oxidative degradation,which adversely affects their performance and service life.This study investigates the aging behavior of PE pipes used for gas transport under the combined effects of temperature(ranging from 80℃to 110℃)and pressure(0,0.1,0.2,and 0.3 MPa).By assessing the characteristics and thermal stability of the aged pipes,relevant efforts are provided to explore the performance variations during the aging process and develop methods for evaluating thermal stability.The results indicate that an increase in aging factors,specifically temperature and pressure,significantly reduces theMeltMass Flow Rate(MFR)of polyethylene pipes,suggesting a decline in the material’s flowability during the aging process.Oxidative Induction Time(OIT)tests show that with increasing temperature and pressure,the oxidative induction time of the aged polyethylene pipes progressively shortens,indicating a significant reduction in the material’s oxidative stability.The application of the Arrhenius equation further demonstrates that the aging reaction rate of polyethylene pipes in high-temperature environments is closely related to both temperature and activation energy,thereby laying the foundation of a new approach for the development of an initial model that can reflect the microscopic behavior of polyethylene pipes in aging environments.
