IMPACT OF HUMIDITY ON THE DIMENSIONAL STABILITY OF POLYMER COMPOSITES

Abstract

This study investigates the hygrothermal behavior of carbon fiber epoxy composites, focusing on the effects of temperature (10°C–50°C) and high relative humidity (90%) on dimensional stability over varying exposure durations. Thirty specimens were subjected to controlled conditions in a climate chamber for up to 432 hours. Baseline measurements indicated an average width of 14.76 mm and average thickness of 3.19 mm. Dimensional analysis revealed width increases of 1.63% (15.00 mm) at 10°C, 1.35% (14.96 mm) at 20°C, 2.03% (15.06 mm) at 40°C, and 0.27% (14.80 mm) at 50°C, while thickness changes were minimal, ranging from 0.31% to 0.94% across most temperatures. At 30°C, width increased slightly (0.068% to 14.77 mm) with no measurable change in thickness. The results demonstrate that temperature and humidity significantly influence the dimensional and mechanical properties of polymer composites. Hygrothermal testing is therefore critical for optimizing composite durability under variable environmental conditions.