1. Plant Polymers Research Unit and Food and Industrial Oil Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Services, U.S. Department of Agriculture, 1815 North University Street, Peoria, Illinois 61604; Department of Chemical Engineering, Pennsylvania State University, University Park, Pennsylvania 16802; Caterpillar Inc., Peoria, Illinois 61656; and Hercules Incorporated Research Center, 500 Hercules Road, Wilmington, Delaware 19808