Document Type

Thesis - University Access Only

Award Date


Degree Name

Master of Science (MS)

Department / School

Agricultural Engineering

First Advisor

Jim Julson


High temperature short time extrusion processing was used to produce a corn flour polystyrene foamed plastic. The resiliency, bulk density and thermal conductivity was measured of the extrudates. The minimum bulk density and thermal conductivity measured was 0.069 g/cm 3 and 0.044 W/m C. The maximum resiliency measured was 89.1%. Three separate multiple regression models were developed to predict resiliency, bulk density and thermal conductivity as a function of extrudate formulation ingredients. The models were used to prepare optimal formulations for extrusion. The resulting extrudates' resiliency, bulk density and thermal conductivity were within the range of commercially available foamed plastics. Viscosity measurements were performed on the formulation producing the lowest bulk density. Rheological flow curve for this formulation depicted pseudoplastic type behavior indicating it has flow properties similar to both starch and plastic polymer.

Library of Congress Subject Headings

Plastic foams
Plastics -- Extrusion
Plastics -- Biodegradation
Corn products




South Dakota State University



Rights Statement

In Copyright