Comparative Analysis of Static and Dynamic Properties of Polyurethane Foams Fabricated Using Polycarbonate Diol and Isophorone Diisocyanate

Flexible polyurethane (FPU) foam was fabricated by varying the contents of polycarbonate diol (PCD) and isophorone diisocyanate (IPDI), and its static and dynamic properties were evaluated. Increasing the PCD content enhanced rigidity owing to stronger hydrogen bonding, which resulted in a higher sag factor and hysteresis loss. However, incorporating IPDI at an optimal NCO index of 0.2 improved network flexibility and reduced microphase separation, thereby decreasing the hysteresis loss by approximately 20%. Morphological analysis revealed that the PCD and IPDI contents influenced both cavity and pore sizes through variations in the system viscosity and reaction rate. Fourier-transform infrared analysis confirmed a lower reaction rate with higher PCD and IPDI contents, attributable to increased viscosity and steric hindrance. Dynamic mechanical analysis showed that the addition of IPDI lowered the glass transition temperature and increased the damping factor (tan δ), indicating improved vibration damping. These results suggest that balanced contents of PCD and IPDI can improve both the comfort and mechanical performance of FPU foam.