Available at: https://digitalcommons.calpoly.edu/theses/2811
Date of Award
6-2024
Degree Name
MS in Polymers and Coatings
Department/Program
Chemistry & Biochemistry
College
College of Science and Mathematics
Advisor
Erik Sapper
Advisor Department
Chemistry & Biochemistry
Advisor College
College of Science and Mathematics
Abstract
The goal of service life prediction is to accurately predict the useful lifetime of a coating system in a typical service environment. Field testing is the most true-to-life form of service life testing but requires long exposure times, often not quick enough to readily aid redesign in the product development cycle. As an alternative, accelerated weathering chambers are used to speed up coating failure in a laboratory setting. These devices do indeed accelerate failure but often produce failure modes that are not seen in actual service or produce material rankings that are not reproducible. This work explores the principle of cumulative stressor damage for an exterior architectural coating being exposed to outdoor conditions in San Luis Obispo, California, as well as an accelerated UV/moisture protocol. The accelerated UV/moisture protocol is executed first by ASTM D4587, and then by creating a custom exposure test cycle based on locally observed weather. Comparison of failure mode and quantification of failure is determined by gloss and spectral reflectance measurements. Finally, acceleration factor determination for the new SLO-in-a-box protocol is outlined, with a discussion of preliminary results.