(459d) Reinforcing Thermoplastics with Natural Fibers Derived from Biofuel Byproducts

A large source of lignocellulosic material exsists in the U.S. in the form of biofuel production by-products, such as dried distillers grains with solubles (DDGS) from corn-ethanol. However, these by-products have a rather restricted application as livestock feed, due to their low nutritional value. This causes their prices to be low relative to traditional lignocellulosic feed stock, and thus their potential use as reinforcing agents in biocomposites has become an attractive opportunity for production facilities with large quantities of derivative waste. With success being seen in the usage of materials traditionally considered filler agents without reinforcement capabilities, attention has begun to be placed on the usage of micro cellulose based natural fiber sources as well. It is in this pursuit that DDGS fibers have been explored as potential reinforcing fibers within polypropylene (PP) to make short fiber biocomposites.

In this work, PP/DDGS composite materials were explored using 10 wt% DDGS fibers within a PP matrix. Samples were prepared in order to determine the optimal processing methodology based on material performance. Mechanical investigation included both tensile and flexural tests performed according to ASTM standards D638 and D790, respectively. Water absorption tests were performed using a test modeled after ASTM D570. In this test, specimens were soaked in boiling water for 1 hour and tested for water absorption, after which they were tested in flexure to observe the resulting mechanical performance. Dynamic mechanical thermal analysis (DMTA) was also performed to observe changes in the glass transition temperature of the samples and subsequent crystallinity.