Potato-based+Bioplastics

Chemistry Concept: As plastics play an increasingly large part in modern life, more efficient processes for creating and recycling plastics are being developed. Traditionally, plastics have been produced from petroleum but recently, new techniques for developing plastics from plants are emerging. Not only can these plant-based bio-plastics be made from products that are already in large scale production (potatoes, bananas, pineapples) but are biodegradable, meaning they can be disposed of easily with minimal effects on the environment unlike petroleum-based plastics. In this project, we hoped to determine what sorts of roles these new bio-plastics can take in the future. By creating our own plastics from potatoes and testing the versatility our products against other petroleum- and plant-based plastics, we intended to determine if bio-plastics are versatile enough to usurp the dominant role of petroleum plastics.

Questions: How do temperature and moisture levels during the formation of the plastic affect the product's properties? (strength, elasticity, water absorption, etc.) How do the plastics we can make compare to petroleum-based plastics? To other bioplastics? Can our bioplastic degrade? How do our bioplastics hold up in water?

Hypothesis: High temperatures and low moisture levels will create harder plastics while low temperatures and high moisture levels produce softer plastics. Bio-plastics will be able to rival petroleum-based plastics in versatility.

Journal Articles: Biodegradable Plastics made from plants: [] Strong plastics from fruit: []

Procedure: []

Materials: Potatoes Water Glycerin White Vinegar Non-stick pan peeler blender

--- Final Report ---

Abstract:

The purpose of this lab was to create bioplastic from corn starch using household materials. The plastic was tested against petroleum-based plastic on its ability to degrade in anoxic water and saline solutions. The degradation was tracked through density change and through the use of pH probes to monitor change while the experiment occurred. Tracking density change would indicate any loss in structural integrity of the plastic. The pH probe would detect the CO2 produced by the degrading plastic, based on the principle that CO2 reacts in H2O to produce the weak acid, carbonic acid ( H2CO3 ), which in turn produces bicarbonate ions ( H3O+ ) that the probe can detect. The hypothesis for the lab was “the bioplastic would degrade faster than the petroleum plastic, and would be observed through a decrease in density and a drop in pH. Also, the saline solution will facilitate degradation at a faster rate than the water.” The results of the lab were mixed, supporting the hypothesis in some cases while refuting it in others. The pH data was inconclusive, only showing that, in order to track degradation in water in this way, the plastic must be left for a longer period than four days. The density results all showed a drop in density for bioplastic samples. Originally, they results showed a drop in density for the petroleum plastic samples as well but a repeat test with better volume measurement techniques showed no density change. This supports the idea that bioplastic breaks down in water, and the force resistance tests, which compared dry and wet bioplastic samples, further supported the idea with quantitative and qualitative data.

Keywords: //bioplastic, petroleum plastic, degradation, pH, carbonic acid, distilled water, saline solution, force resistance//

Figure of Apparatus:

Fig. 1: The force testing apparatus.

Summary Graphic:





media type="file" key="Aditi Francesco Audio Recording.wav" width="300" height="50" Citations:


 * Brandon121233. (2007). //Make potato plastic!//. Retrieved from []
 * Cliff. (2009, April 11). //Definition of plastics//. Retrieved from []
 * Lenntech. (1998). //Carbon dioxide//. Retrieved from []