The scope of this research is to evaluate the effect oil based polyurethane has on Poly-Lactic Acid (PLA) when used as thin protective film against degradation, and how PLA performs when used as matrix material in a natural fiber composite. Course woven jute fabric (burlap) is being used as natural fiber reinforcement. PLA is synthesized from corn starch which makes the polymer biodegradable, but the amount of degradation is dependent on the conditions the material is subjected to. Panels of plain PLA and PLA reinforced with burlap were prepared through the use of a hot press and steel die. The panels were then machined into tensile and Flex bars. A set of the non-reinforced samples were coated with oil based polyurethane. Accelerated weathering chambers were used to weather the samples at two different conditions for several months. The reinforced samples and a set of the non-reinforced samples both coated and uncoated were subjected to alternating cycles of ultra violet light and humidity levels of 90 to 100 percent at temperatures of 50 degrees centigrade. Another set of non-reinforced samples both coated and uncoated were subjected to humidity levels of 90 to 100 percent at temperatures of 50 degrees centigrade. Mechanical properties of the samples were tested according to ASTM standards on a weekly basis. Thermal analysis was also performed using a Differential Scanning Calorimeter and a Thermo-Gravimetric Analyzer. The mechanical testing revealed that the overall degradation of the PLA was lower in the coated samples and highest in the reinforced samples.