Comparative Study Between the Bioplastic Properties of Agar-Agar (Gelidium amansii) and Potato (Solanum tuberosum) Starch
Kyle Emmanuel A. David
Rynno Gabriel Luis T. Garde
Justin Carlo P. Gregorio
Rufo Angelo M. Mauricio III
Christian Michael A. Perreras
Miss Alvie Diaz
January 30, 2012
Bioplastic is a form of plastic derived from renewable biomass sources rather than fossil-fuel plastics which are derived from petroleum. Two main ingredients are commonly used in the production of bioplastic: starch and seaweed. The study aimed to compare the properties of bioplastic made from agar-agar, a species of seaweed, and potato starch. Through the study, the researchers attempted to discover which bioplastic would be more viable for both industrial and personal use, in terms of its tensile strength, flexibility, water resistance and mouldability.
In the procedure, for the first set-up, vinegar, glycerol and water were mixed in a bowl together with potato starch. The second set-up had a similar mixture, although instead of adding potato starch, agar-agar was used. Both mixtures were heated until they reached about 95 ͦC. Thereafter, half of the solutions were poured separately onto two different drying pans and were left to dry.
The final products were then subjected to four tests that aimed to determine which plastic had all of the properties mentioned above. Both plastics were proven to be flexible and mouldable. However, the agar-agar plastic had greater tensile strength compared to the potato starch plastic. After 26 hours of soaking in water, the agar-agar plastic was proven to be water-soluble, instead of water resistant, while the potato starch plastic maintained its shape and weight.
Based on the results of the experiments, the researchers concluded that both plastics are useful. The agar-agar plastic may be used as a packaging material that can carry heavy but dry items, while the potato starch plastic may be used as a packaging material for both wet and dry items.
As concern for the use of petroleum-based products and their effects on the environment increases, industries have started to investigate several other sustainable resources for the creation of bioplastic. Bioplastic covers approximately 10-15% of the total plastics market toady and is estimated to increase its market share to 25-30% by 2020. Over 500 bioplastic processing companies already exist worldwide. The group investigated these alternative sources, specifically agar-agar (Gelidium amansii) and potato starch, that would provide a better and more practical plastic. These two ingredients were selected by the researchers because they can be easily acquired and are abundant in the Philippines. The study’s first goal was the creation of such plastics for testing. The second was to test the two plastics in the following categories: water resistance, flexibility, tensile strength and mouldability. This research aimed to bring awareness to the consumers, as well as to the manufacturers on the feasibility of using these biodegradable plastics that could eventually spawn a bioplastic industry in the Philippines. This would provide an environment-friendly alternative to the non-biodegradable plastics that fill dumps, clog waterways and whose production emits high amounts of greenhouse gases. It was the researchers’ hypothesis that both plastics would be strong enough to bear a reasonable amount of weight and that both would be waterproof, flexible and mouldable.
The study was based on previous scientific researches stated below and an Experimental Research Design regarding the production of agar-agar plastic conducted by First Year High School students of La Salle Green Hills (David, 2011). An instructional...