A review of the implications of polyethylene plastics when utilized as chemical storage tanks

Abstract

Many studies have been conducted to investigate the impact or influence of polyethylene (PE) plastic when used as chemical liquid storage. Herein, this literature addresses the factors that contribute to the degradation of chemical storage tanks as a result of PE plastics and how they can be mitigated. This is achieved by reviewing and discussing the significant properties of High-density polyethylene (HDPE), which have been reported to degrade the chemicals stored in these storage tanks. The method of cross-linking the PE was reviewed with its preceding processes that involve chemical and physical processes. The influence of each agent on the resulting properties is discussed in detail including the effect of cross-linking degree. These methods were found to be significant in improving some of the properties of HDPE to better store chemical substances. Nonetheless, it was established that the main concern of PE plastics is environmental stress cracking (ESC), which causes unexpected cracks within the HDPE storage tanks, thus degrading the substance contained. The currently used method or test (bentstrip) to determine the resistance of PE to ESC and techniques used to monitor it were reviewed and discussed in detail. Consequently, the literature suggests that the relationship between the density of PE and its ESC susceptibility has been found to be significant. However, research has shown that relying solely on density as a predictor of ESC in PE when exposed to chemical substances is insufficient, and further studies should be conducted to investigate other parameters that contribute to ESC in PE. In addition, the review suggests that future research should focus on studying ESC resistance of newly developed Nano-filled PE composites or biodegradable PE variants, as these are future materials for storing chemical substances conveniently.