Corn starch plasticized with isosorbide and filled with microcrystalline cellulose: Processing and characterization

Innovative, green and fully biodegradable biocomposites, based on plasticized corn starch, were prepared by melt processing and filled with microcrystalline cellulose (MCC). Isosorbide and glycerol were used as plasticizers. The effect of the type and content of the plasticizer and the filler addition on processing, surface morphologies, crystallinity and thermal stability were investigated. Aged materials were analyzed too to study the retrogradation phenomena along the time. The processing using isosorbide required lower temperatures but greater shear and processing times leading to more homogeneous biocomposites. With isosorbide, higher crystallinity and no retrogradation signals were observed as clearly occurred with glycerol. The thermal stability of biocomposites was high too. These properties enhanced in a greater extent when the isosorbide content was 35% and with the MCC incorporation, the last due to a good adhesion of MCC to the matrix. These biocomposites could be a good option for packaging applications.