May 11, 2010

Midwest Biopolymers & Biocomposites Workshop

 

Poster Abstracts

102: Soy Protein-based Plastics: Improving Water Stability Utilizing Functional Chemistry and Fiber Additives

David Grewell1, Sean T. Carolan1,3, and Gowrishankar Srinivasan2

1Department of Agricultural and Biosystems Engineering, 2Department of Material Science and Engineering, 3Corresponding Author
Iowa State University, Ames, Iowa


Anhydride chemistries such as maleic anhydride (MA), phthalic anhydrides (PTA), and butylated hydroxyanisole (BHA) were used in conjunction with glycerol as plasticizers to produce relatively water stable soy protein-based plastics. The various formulations were extruded and injection molded to form the samples for characterization. The percentages of anhydrides were varied between 3-10% tw/tw (total mass). PTA formulations performed better overall where 10% PTA plastics were observed to have a water absorption level as low as 21.5% after 24 hours of exposure to water in comparison to 250% for the control formulation. Both MA and PTA formulations were characterized using Fourier transform infrared spectroscopy (FTIR) to confirm the fundamental mechanisms of water stability. In addition, the formulations were modified by inclusion of cotton fibers and cotton powders in order to improve mechanical properties. The cotton fiber formulation improved the dry strength by 18%, but did not significantly improve the wet strength. It was also observed that the BHA formulation exhibited high extension values (not detailed in this poster).