Submitted to: American Chemical Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: August 27, 1998
Publication Date: N/A
Technical Abstract: The solution rheological behavior of various OATRIM materials and cooked oat bran were investigated. The rheological properties of the solutions were investigated using thixotropic loop, small-amplitude oscillatory shear, and steady-state shear experiments. The cooked oat bran exhibited shear-thinning behavior during a thixotropic loop experiment over a shear rate range of 0 to 250 s**-1. In contrast, certain OATRIM solutions exhibited an unexpected region of shear-thickening behavior with a critical shear rate of 50 s**-1. Subsequent thixotropic loop experiments displayed the shear-thickening region for OATRIM indicating that the network structure can be reformed during the imposition of a shear field. Start-up of steady-state shear on OATRIM solutions, above the critical shear rate for shear thickening, exhibited nonlinear stress-overshoot behavior. The presentation will discuss the findings and compare the experimental results to the predictions of linear and nonlinear viscoelastic models.