Tuning of renewable sponge‐like polyurethane physical‐chemical and morphological properties using the pullulan as a reactive filler

Abstract This study aimed to evaluate the effect of pullulan (Pull) on a renewable polyurethane sponge‐like scaffold synthesized from the Pull mixture with the castor oil‐based polyol and the prepolymer using the situ foaming method. The Pull contents on the sponge‐like are 5, 10, and 20 wt.%. The samples were evaluated by optical microscopy (OM), scanning electron microscopy (SEM), density, Fourier transform infrared spectroscopy (FTIR), contact angle, Thermogravimetry, X‐ray diffraction analysis (XRD), and compression strength test, respectively. FTIR results indicated that Pull was hydrogen‐bonded to PU foam chains and increased the sponge‐like scaffolds density, inducing a decrease in average cell size compared to the pristine PU, confirming that they act as nucleating agents. The Pull addition improved PU foams' hydrophobicity and mechanical properties and caused a thermal stability median between Pull and pristine PU. Thus, all renewable sponge‐like scaffolds were hydrophobics and presented appropriate mechanical behavior, exhibiting better physicochemical properties, and appearing as promising candidates for biomedical applications.