Design, Preparation and Characterization of Self-Reinforced Starch Films through Chemical Modification

A new technique for design and preparation of self-reinforced starch films is introduced. The films were based on a high-amylose corn starch that was chemically modified in different ways. Hydroxypropylation was used to decrease gelatinization temperature and improve processability. The reinforcing component consisted of cross-linked starch granules, where the crosslinking increased granule thermal stability and moisture resistance. Distribution of the crosslinked starch was imaged by CLSM, and the matrix/particle interface was studied by SEM. Modulus and tensile properties of the starch film were increased by about 30 and 20%, respectively, after addition of rigid cross-linked starch particles. A perfect interface between matrix and reinforce agent was obtained.