Protein Plastics from Soybean Products J
GEORGE H. BROTHER AND LEONARD L. MCKINXEY U. S . Regional Soybean Industrial Products Laboratory, TJrhana,
R
ECENT developments have made it possible to a p proach from new angles the problem of developing a
protein plastic molding material. Earlier work in this line was confined to forming the water-plasticized soft material to shape and then hardening it iri formaldehyde solutions and drying. The incorporation in the waterylasticized soft mat.erial of weak or dormant hardening agents which would become active after the object had been formed to shape was the only alternative. Aside from other objections and weaknesses which are numerous and serious, the product does not come finished from the die in any of these processes but must dry down to normal moisture conteut, with accompanying shrinkage and warpage. Also, the product is left porous and readily absorbs water even from humid air. Consequently, it has not been possible to develop a protein plastic molding materialup t o the present time. Some protein materials, notably soybean protein and prolamines such as zein from corn, possess a tendency towards plastic flow even at. reduced water content (f). It was sug-
* For previow pnpera in this ~ e i i e a ,eee Literature citations ( 2 ) and (B).
* A cooperstive orgeniration pwtioipsted in by the Bureaus of Chemistry and Soils and of Plant Industry of the TJnited States Department oi Airicultwe, and the Agriouitud Experiment Stations of the North Central Ytates of Illinois, Indians, Iowa, I
