Submitted to: American Chemical Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: August 24, 2000
Publication Date: N/A
Technical Abstract: The effect of starch granule size on the viscosity of starch-filled poly (hydroxy ester ether)(PHEE) biodegradable composites was investigated with different sizes of potato starch. Potato starch was separated using an air classifier into different particle size fractions: <18, 18-24, 24-30, and >30u. The starch was dried to a moisture content of 0.5% to minimize moisture effect on composite rheology. PHEE and potato starch were extruded using a twin screw extruder with starch volume fraction of 0.46. Stress relaxation, frequency and strain sweep, and temperature step measurements were carried out. It was found that the viscosity of starch/ PHEE composites was invariant to the starch granule size. Maron and Pierce model for the relationship between the relative viscosity (ratio of composite viscosity to that of unfilled polymer) and the filler volume fraction was used to describe the experimental data.