Operational maps between molecular properties and environmental stress cracking resistance

Abstract

ABSTRACTEnvironmental stress cracking (ESC) is one of the main failure mechanisms involved in polymer fractures. This work focuses on the ESC resistance (ESCR) of polyethylene (PE) in which ESC occurs through a slow crack growth mechanism. To predict the ESCR of PE, it is necessary to fully understand the molecular structure of the resin. This work demonstrates the relationships between molecular structure characteristics and material responses based on experimental characterization and published literature trends. Relationships between ESCR, molecular weight, percentage crystallinity, and density were used to create ESCR and molecular structure maps, which can be used to improve the development of PE resins with a desirable (better/higher) ESCR. These maps along with a logical flow chart offer practical prescriptions and describe pathways toward the development of PE with a desirable ESCR. In addition, this work presents case studies that demonstrate the effectiveness of this approach. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47006.