Performance evaluations of flexible polyurethane foams manufactured with castor oil-based bio-polyol

Flexible polyurethane (PU) foams are widely used in automotive industries as sound absorbing materials because their porous structure is beneficial for absorbing sound waves. With growing concerns about environment pollution, many studies have been conducted to investigate the environmental impact of the PU foams fabricated with bio-derived materials instead of using petroleum-based sources. In this study, castor oil-based bio-polyol and two types of gelling catalysts (amine and tin) were applied in synthesis of the PU foams, and the sound absorption, compression strength, and volatile organic compounds (VOCs) emission were examined. Increasing the bio-polyol content and applying a tin type catalyst decreased the cavity and pore sizes about 40%, resulted in high sound absorption (acoustic activity: 0.77 and noise reduction coefficient: 0.41) and compression strength (26.27 kPa). Additionally, the application of bio-polyol also reduced the VOCs emissions from the foam degradation. Thus, applying the bio-derived polyol is promising for reducing environmental issues in various industrial applications.