2 - Why is service life prediction of polymers and plastics exposed to outdoor weathering important? An industrial perspective

Abstract

The ability to predict the service life of materials is central to effective risk assessment for many products. Like the tools and methodologies for the broader evaluation of risk, service life prediction (SLP) is a methodology that is both well established and continuously improving, challenging researchers to increase the insight and accuracy of prediction within acceptable ranges of speed and cost. As our collective understanding of accelerated aging, failure modes, and predictive models improves, so does our ability to elucidate the relationship between environmental variables and a given material’s response. However, formidable challenges—both technical and practical—remain. Understanding failure modes and underlying mechanisms is essential to accurately predicting service life via accelerated testing. Importantly, the real world can be much more complex than accelerating exposure to a single factor. Thus, useful testing in support of lifetime analysis requires that the operative mechanism that governs a given material’s service life is activated in the accelerated test. One of the enduring challenges of successfully implementing SLP into the product development lifecycle is the difficulty of predicting the results of often complex real-world usage. This work provides a roadmap to the SLP process followed by two case studies that highlight the practical intersection of SLP and risk assessment in industry. One study establishes how SLP has been used effectively to describe lithium ion battery performance in an electronic device to facilitate operational choices to extend lifetime. A second study demonstrates the unintended service life reduction due to formulation change in a building sealant.