Structure–property behavior of the palm olein-based natural oil polyol (E-135 NOP) was investigated in viscoelastic “memory” foams. In a model viscoelastic foam formulation, the E-135 NOP with pendant hydroxyls was used as a drop-in replacement for the well-defined model polyether polyol with terminal hydroxyls, Poly-G® 76-120. Both polyols have comparable equivalent weight and concentrations of primary and secondary hydroxyls. The data showed that replacing Poly-G® 76-120 polyether polyol with the E-135 NOP did not significantly impact the foaming reactivity. Increasing the E-135 NOP concentration in the VE foams increased the average foam cell size while maintaining the open cell structure. Aging properties of the VE foams were mostly unaffected by the replacement of the Poly-G® 76-120 with the E-135 NOP. Furthermore, addition of E-135 had no impact on foam density; however, it increased the support factor of the viscoelastic foams. Differential scanning calorimetry, dynamic mechanical analyzer, and Fourier transform infrared spectroscopy analyses indicate less defined morphological separation of hard and soft segments in the viscoelastic foams with higher concentration of E-135 NOP. Overall, the results demonstrated the feasibility that natural oil polyols can be used in viscoelastic polyurethane foams to replace a significant portion of the polyether polyols with comparable equivalent weights and concentrations of primary and secondary hydroxyls. In future, the feasibility study of E-135 NOP as a drop-in replacement of combination polyether polyols in viscoelastic foams formulation will be conducted. Furthermore, the effect of palm olein-based natural oil polyol in high resilience foam will be evaluated.
