Effect of compounding and plastic processing methods on the development of bioplastics based on acetylated starch reinforced with sugarcane bagasse cellulose fibers

Fiber-reinforced starch-based bioplastics provide an excellent alternative to synthetic materials for packaging. Hence, it is important to develop materials based on starch and natural fibers on an industrial scale. The effect of compounding thermoplastic acetylated corn starch (TPAS)/sugarcane bagasse cellulose fibers (SF) biocomposites using both single and twin-screw extruders (SSE and TSE) and the effect of plastic processing methods such as compression molding, injection molding, and flat film extrusion on physical properties of starch-based bioplastics were studied. Bioplastics were characterized using AFM, XRD, SEM, rheometry, tensile tests, water-solubility, contact angle, and weight loss during soil burial. Compounding the TPAS/SF biocomposites by TSE resulted in a significant decrease in the fiber length and a more homogeneous distribution of SF in the TPAS matrix than SSE. The biocomposite processing by injection reduced the fiber's length even more and improved the SF distribution and mechanical properties. The biomaterials' solubility ranged from 24.9% to 28.2%, which is lower than native starch-based biocomposites. Therefore, it was possible to develop TPAS/SF bioplastics on an industrial scale to be an alternative to conventional plastics.