Effects of hygrothermal exposure on the mechanical properties of injection molded glass‐fiber reinforced poly(phenylene sulfide)

Abstract An experimental program was used as the foundation for long‐term property prediction for a glass‐fiber reinforced poly(phenylene sulfide). Samples were aged up to 226 days at 95% RH at both 104°F (40°C) and 158°F (70°C) (based on MIL‐STD‐810E and MIL‐STD‐210C), and their mechanical properties measured. Data analysis indicated that property changes were more pronounced at the higher temperature with statistically significant changes, at the 99% confidence level, occurring after 100 days. At the lower temperature, property changes were observed, but their significance was not established. Further analysis of the data indicated that the moisture content did not affect the property changes. Analysis of the data using a viscoelastic description of the property changes resulted in property maps that permit estimation of the mechanical properties for up to a 20‐year exposure as a function of exposure temperature.