J.D. Kim, S. Kim , T. Schmutz, C. Malchaire, D. Scholz, K. Keck
Papers # 2018 Las-Vegas
Since a few years, pipe producers are facing the challenge to protect their plastic pipe from degradation due to chlorine dioxide. Unfortunately, most existing stabilization solutions are not effective enough to insure the desired lifetime of the material. This study shows how the latest development allow to top-up current stabilization to extend durability of polyolefin pipes. When samples are exposed to hot water containing chlorine dioxide, one of the solutions extends OIT of pipe samples more than 4 times at lower temperature and more than doubles it at higher temperature. It also shows limited surface crazing of lab samples.
Chlorine dioxide (ClO2) is much more aggressive than hypochlorous acid and leads to premature failure of polyethylene pipes. Many studies have been conducted until now to understand the degradation mechanisms. This paper shows how to significantly improve the stabilization of polyethylene pipes in contact with water containing ClO2 to reach the requirements of pipe standards. Several additive compounds were evaluated in order to increase life time against ClO2. New experimental proprietary formulation shows very high oxidation induction time (OIT) retention compared to standard formulation when exposed to ClO2 containing water environment. Therefore, it is an ideal solution for PE-Xb and HDPE water pipes. In addition, this new experimental propriety formulation can be combined with a synergist to further extend lifetime.
