PREPARATION AND PROPERTIES OF POLYURETHANE ELAEOSTERIN INTERPENETRATING POLYMER NETWORKS COATING TO REGENERATED CELLULOSE FILMS/

Castor oil-based polyurethane/elaeostearin (PU/Es, 70:30) coating was synthesized and characterized by using infrared spectroscopy (IR), dif ferential scanning calorimetry (DSC), and X-ray diffraction (XRD). The results indicated that the PU/Es cured at 100 degrees C formed interp enetrating polymer networks (IPNs), and the formation of PU networks w as faster than the polymerization of Es, which belongs to free-radical reactions. The intensity of hydrogen bonds in the PU/Es IPNs decrease d with increasing Es content in the studied range, suggesting that the partial hydrogen bonds in the PU were broken by interpenetration of E s polymer. The regenerated cellulose films coated with PU/Es IPNs were more readily cured than those coated with only Es. Meanwhile, IR and DSC measurements revealed that chemical bonds exist in the interface b etween the cellulose film and the coating layer in the coated films, r esulting in the strong adhesion. The interfacial bonding strength, wat er resistivity, mechanical properties, and biodegradability of the cel lulose films coated with PU/Es were much higher than those of the film s coated with PU.