Abstract: This invention discloses a method of preparing and extruding biodegradable starch blends into biodegradable products in such a way that preprocessing steps, such as gelatinizing or destructurizing of the starch, are not required. Unprocessed raw starch is combined with biodegradable copolymers such as polyvinyl alcohol (PVOH), or ethylene vinyl alcohol (EVOH), a nucleating agent, and a plasticizer. The combination may be processed using a twin-screw mixer, and blown into a film. The method described in this invention alleviates pre-preparation steps, reduces the cost and time required to prepare and extrude starch-based biodegradable materials, eliminates the need to use expensive pre-processed starch, and results in a substantially completely biodegradable product.

Abstract: A method and composition are provided for making biodegradable injection ded parts from 30% to 70% cellulose acetate, 10% to 60% unmodified raw (whole) starch and 5% to 35% plasticizer including glycerols and glycerol acetates. Other ingredients that can be used include: starch, flour and paper acetates; gelatin; boric acid; and agricultural fillers. The solid ingredients are combined and fed to an extruder used to make pellets or to feed injection molding equipment. The resulting parts are clear to white or colorful depending upon the added filler materials. The plastics formed are water resistant, high strength and biodegradable.

Abstract: A method of forming a crosslinked chitosan polymer comprises contacting cosan with a basic solution of an epihalohydrin compound and heating the resulting mixture to a temperature and for a time sufficient to effect crosslinking of the chitosan. The crosslinked chitosan polymer exhibits water insolubility and biodegradability.