Novel thermoplastic materials based on the outer-shell oxypropylation of corn starch granules.

The study of the plasticization of corn-starch granules through the bulk oxypropylation of their outer shell produced a novel biphasic material consisting of a low glass transition temperature component surrounding the granules' inner core, which could be hot pressed to form films of the granules dispersed into a thermoplastic matrix. The success and extent of these chemical modifications and the properties of the ensuing composites were assessed by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, and contact angle measurements. This approach has the additional advantage of being simple and "green".