Water Absorption Properties and Morphology of Polypropylene/Polycarbonate/Polypropylene-graft-Maleic Anhydride Blends

This work investigates the effect of blending polycarbonate (PC) into polypropylene (PP)
matrix polymer on water absorption properties and morphology. The blends, containing 5% to 35% of
polycarbonate and 5% compatibilizer, were compounded using twin – screw extruder and fabricated into
standard tests samples using compression molding. The compatibilizer used was
polypropylene-graft-maleic anhydride (PP-g-MA). In water absorption test, specimens were immersed in
distilled water at 23oC and 100oC. In 23oC immersion, PC showed the highest absorption at 0.362 wt%,
while PP was the lowest at 0.064 wt%. The blends demonstrated transitional absorption value between PP
and PC. In 100oC immersion, 90/5/5, 80/15/5, and 70/25/5 compositions (PP/PC/PP-g-MA) exhibited
lower absorption than PP, indicating enhanced long – term degradation resistance in water compared to PP.
Microscopy analysis showed that PC existed as fibers, dispersed throughout PP matrix.