Submitted to: Annual Meeting of the Bio Environmentally Degradable Polymer Society
Publication Type: Abstract Only
Publication Acceptance Date: August 21, 1999
Publication Date: N/A
Technical Abstract: This research focuses on the flow behavior of highly starch-filled poly (hydroxy ester ether)(PHEE) biodegradable composites. In this paper, temperature dependence of viscosity is presented. Corn starch (Buffalo 3401)/PHEE (Dow Chemical) were extruded using Leistritz twin screw extruder with starch volume fractions from 0.27 to 0.66. Dynamic strain strain sweep measurements were carried out using ARES Rheometric Scientific) at 10 rad/s and at six different temperatures from 100 to 150 deg C. Correlation equations (Arrhenius, WLF) were applied to explain temperature dependence of melt viscosity. The activation energy for flow in Arrhenius equation was found to be of 6x10**4 J/mol for pure PHEE and composites with starch volume fraction smaller than 0.46. Deviation from the correlations at high starch concentration was explored from different aspects (yield stress and non-linearity). The non-linearity yoccurred at high starch concentration is considered as the main reason for strain (stress) dependence of the melt viscosity. This research was conducted under CRADA 58-3K95-8-0635 between the Agricultural Research Service and BRDC.