title: Rheological studies utilizing various lots of zein in N,N-dimethylformamide solutions.
abstract: Rheological studies were carried out on solutions of zein in N,N-dimethylformamide (DMF), where the specific lot of zein, concentration, time, and temperature were varied. DMF is a good solvent for zein, giving clear, relatively low viscosity solutions. It was found that all of the zein solutions behaved in a non-Newtonian fashion. At high concentration and elevated temperature, zein solutions will increase in viscosity with time. A temperature study on the rate of viscosity rise illustrated that at temperatures above 40 degrees C, the rate of viscosity rise increased in a non-Arrhenius fashion. There can be significant lot to lot variations in commercially obtained zein that gives rise to differences in viscosity and rate of viscosity rises. With the samples studied, viscosity was found to double from one lot of zein to another. Size exclusion chromatography suggests that compositional differences between the lots drive the observed differences in viscosity.
authors.affiliation: Plant Polymer Research, National Center for Agricultural Utilization Research, Agricultural Research Service, U.S. Department of Agriculture, Peoria, Illinois 61604, USA. sellingg@ncaur.usda.gov
authors.forename: Gordon W
authors.initials: GW
authors.lastname: Selling
authors.forename: John
authors.initials: J
authors.lastname: Lawton
authors.forename: Scott
authors.initials: S
authors.lastname: Bean
authors.forename: Christopher
authors.initials: C
authors.lastname: Dunlap
authors.forename: David J
authors.initials: DJ
authors.lastname: Sessa
authors.forename: Julious L
authors.initials: JL
authors.lastname: Willett
authors.forename: Jeff
authors.initials: J
authors.lastname: Byars
mesh_terms: D004126:Dimethylformamide; D005559:Formamides; D011108:Polymers / Q000737:chemistry; D012212:Rheology; D012996:Solutions; D012997:Solvents; D013816:Thermodynamics; D014783:Viscosity; D015028:Zein / Q000737:chemistry*
chemical_list: D005559:Formamides; D011108:Polymers; D012996:Solutions; D012997:Solvents; D004126:Dimethylformamide; D015028:Zein