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

This study investigates the effect of blending polycarbonate (PC) into polypropylene (PP) matrix polymer on water absorption properties and morphology. The blends, containing 5-35% 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 23 and 100°C. In 23°C 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 100°C 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.