(217cb) Synthesis of Green Polyurethane Foam Using Waste Glycerol and Hay Fibers

There is a worldwide effort to develop plant-based materials that are alternatives to materials derived solely from non-renewable petroleum and forest wood sources. There is growing interest to minimize future deforestation by eliminating or reducing the amount of wood in commercial products by using agricultural plant-based materials as enhancements or substitutes in hybrid composite materials that utilize synthetic plus plant-based materials. To become viable alternatives for widespread usage, such composites must be comparable or superior in economic, material properties and environmental criteria.

We have incorporated waste by-products of biodiesel synthesis, and waste agricultural fibers in polyurethane-based “Biofoams”. In our lab, we are starting with plant-based cooking oils to chemically synthesize biodiesel.  Unfortunately, about 20% of the cooking oil gets converted to glycerol, a by-product that has little economic value, and is, therefore, considered as “waste”. We developed a chemical synthesis scheme to incorporate small amounts of this glycerol and chopped hay fibers into the foams. In our preliminary studies, we found that five weight percent of biodiesel waste glycerol, or crude glycerol, and 10 weight percent chopped hay in the polyurethane chemistry gave optimum mechanical properties of the Biofoam; however, we continue to explore other chemical routes to increase this percentage. To measure the mechanical properties, ASTM protocols were followed to measure the compression strengths. Our initial measurements indicate that the addition of hay fibers into the polyurethane foam results in lower density and lower compression strength. We envision that this preliminary work can lead to the development of low-cost green composite materials that could potentially be used in certain commercial applications.