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ARS Home » Midwest Area » Peoria, Illinois » National Center for Agricultural Utilization Research » Plant Polymer Research » Research » Publications at this Location » Publication #124199
Title: BAKED STARCH FOAMS:EFFECTS OF STARCH MODIFICATION AND ADDITIVES ON PROCESSING PARAMETERS, STRUCTURE AND PROPERTIES

Author
item Shogren, Randal
item Lawton Jr, John
item TIEFENBACHER, K - FRANZ HAAS MACHINERY, VA

Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/30/2002
Publication Date: N/A
Citation: N/A

Interpretive Summary: Renewable materials such as corn and wheat starches have the potential to replace oil based plastics in applications such as disposable cups, plates and sandwich containers but suffer from brittleness and poor water resistance. This work describes how foam plates having improved properties can be prepared by baking starch together with wood fibers, a water repellent additive and polyvinyl alcohol, a synthetic biodegradable polymer, inside a hot mold. It was found that both plate brittleness and baking time could be reduced by chemically modifying the starch. Including the other additives, the foam plates appeared to have adequate flexibility and water resistance to function as clamshell type hot sandwich containers. This information should be useful to companies currently involved in making disposable articles from starch as well as other scientists studying starch based biodegradable plastics.

Technical Abstract: Various modified starches and additives were tested in baked foam plate formulations in order to improve strength and water resistance properties. Foam plates made from chemically modified starches had shorter baking times, lighter weights and higher elongations at break than unmodified starch. Plates made from genetically modified (waxy) starches and polyvinyl alcohol (PVOH) had elongations to break at low humidities with were much higher than those made from normal starches and PVOH. Addition of softwood fibers increased starch foam plate strengths at low and high humidities. Addition of monostearyl citrate to starch batter formulations gave the best improvement in water resistance among the compounds tested. Baked foams made from potato amylopectin, PVOH, aspen fiber and monostearyl citrate appeared to have adequate flexibility and water resistance to function as clamshell-type hot sandwich containers.