Comparative study of the behavior of chlorinated polyvinyl chloride and random polypropylene pipes under hydrothermal aging

This paper examines the hydrothermal aging characteristics of the two most popular thermoplastic polymers in piping systems: chlorinated polyvinyl chloride (CPVC) and random polypropylene (PPR). Aging was done at various temperatures (23, 69 and 90 °C) across 90 days to cause the samples to act in the long‐term service conditions. Tensile tests demonstrated that mechanical properties degraded with temperature as the tensile strength of PPR declined from 40 to 28 MPa between 23 and 90 °C; CPVC showed better performance as the tensile strength declined from 75 to 52 MPa. Elongation at break also decreased with temperature. On the basis of these findings, a static damage model that was used to calculate lifetime predictions under hydrothermal conditions was used. In this way, it will be possible to estimate the service life of plastic pipes and gain knowledge about gradual structural changes that take place over time. © 2026 Society of Chemical Industry.