Cellulose-based films with internal plasticization with epoxidized soybean oil

A process was developed combining two natural-based products to obtain bio-based films. Industrial cellulose pulp was dissolved and mixed with epoxidized soybean oil (ESBO), which acts as an internal plasticizer. A distillable and recyclable ionic liquid-based solvent was used to dissolve the cellulose. Appropriate distribution of the cellulose/ESBO solution on glass surfaces and careful regeneration of the cellulose enabled the development of solvent-free and flexible cellulose films. Fourier transform infrared spectroscopy revealed the presence of the triglyceride structure and the absence of the epoxide ring in the films, confirming the chemical reaction between the hydroxyl and epoxide groups of cellulose. The resulting films were further characterized by scanning electron microscopy, dynamic scanning calorimetry, thermogravimetry, and mechanical tensile tests. The films were also evaluated by contact angle measurement, swelling ability, in vitro degradability and cytotoxicity. The results showed that the presence of ESBO can adjust both the flexibility and hydrophilicity of the cellulose films, resulting in materials suitable for a variety of applications.