Crosslinked native and waxy starch resin compositions and processes for their manufacture

A method of making an enhanced starch resin composition, said method comprising:

• providing a gelatinized starch mixture comprising gelatinized native and/or waxy starch;
• precuring the gelatinized starch mixture with a sufficient amount of a multi-functional polycarboxylic acid in the presence of a sufficient amount of a non-toxic, water-soluble catalyst effective to catalyze esterification of the native starch and/or the waxy starch with the multi-functional polycarboxylic acid, thereby yielding a precured starch mixture;
• and
• curing the precured starch mixture at a sufficient temperature for a sufficient period of time to yield a crosslinked starch resin composition comprising the native starch and/or the waxy starch crosslinked with the multi-functional polycarboxylic acid,
• wherein said crosslinked starch resin composition has at least one enhanced mechanical property and/or reduced absorption as compared to the native starch and/or the waxy starch, wherein the enhanced starch resin composition is in the form of a nanocomposite.