Operational maps between molecular properties and environmental stress cracking resistance (ESCR)

This is the peer reviewed version of the following article: Sardashti, P., Stewart, K. M. E., Polak, M., Tzoganakis, C., & Penlidis, A. (2019). Operational maps between molecular properties and environmental stress cracking resistance. Journal of Applied Polymer Science, 136(4), 47006. https://doi.org/10.1002/app.47006, which has been published in final form at https://doi.org/10.1002/app.47006. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.Environmental stress cracking (ESC) is one of the main failure mechanisms involved in polymer fractures. This paper focusses on the environmental stress cracking resistance (ESCR) of polyethylene (PE) in which ESC occurs through a slow crack growth mechanism. In order to predict the ESCR of PE, it is necessary to fully understand the molecular structure of the resin. This paper demonstrates the relationships between molecular structure characteristics and material responses based on experimental characterization and published literature trends. Relationships between ESCR, molecular weight (MW), 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 towards the development of PE with a desirable ESCR. In addition, this paper presents case studies that demonstrate the effectiveness of this approach.The authors gratefully acknowledge financial support from the Natural Sciences and Engineering Research Council (NSERC) of Canada, the Canada Research Chair (CRC) program, and the Ontario Graduate Scholarship (OGS) program. Many thanks also go to Imperial Oil Limited, Sarnia, ON, Canada, for financial support and for providing resins for the study over many years