6th Annual Judith Ramaley Celebration of Research and Creative Scholarship
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Poster #14 Prolonging the Structural properties of Poly-Lactic Acid based Composites
Zachary Block and Stoch Sabo
Faculty Mentor: Maryam Eslamloo-Grami
There is a continued interest in biodegradable composites and plastics, along with the desire for green materials. Poly-Lactic acid, which is a biodegradable polymer produced from corn starch, is one material that can fill this need, however the polymer degrades fast enough that most structural integrity is lost in a short period of time.
Panels composed of biodegradable Poly-Lactic Acid (PLA) with a course woven jute fabric (Burlap) and without any reinforcement were made by using a hot press, the conditions used to create the polymer panels were specific to the size of the mold and the amount of material used. In order to control the degradation of the samples, some of the tensile and flex sample bars were coated with oil based polyurethane and then exposed to a controlled environment through the use of an advanced weathering chamber that uses alternating cycles of UV light, 100 % humidity at 55o C temperatures. On regular intervals during the weathering process mechanical testing was carried out through flex and tensile tests. The tests were performed before and after a specified amount of time was spent in the chamber in order to gauge the amount of degradation that took place over time. Thermal analysis was also carried out on some samples using a Thermo-Gravimetric Analyzer and a Differential Scanning Calorimeter, and Dynamic Mechanical Analyzer before and after exposure. Mechanical testing showed a decrease in the tensile strength as time of exposure increased however, the panels that were coated with the polyurethane had slower degradation compared to the uncoated samples. |
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