Title : A Novel biosourced and biodegradable plastic with antimicrobial and antitranspiration Functions
Plastics in the market are produced from fossil sources. These plastics have extremely stable chemical structures against natural degradation, leading to great concern over plastic pollution. Thus, there is considerable interest in biodegradable plastics. Current biodegradable plastics, such as polylactic acid, and oxo-degradable plastics require a special composting facility to degrade, which are largely inaccessible to individuals. The objective of this project is to produce a biosourced and biodegradable plastic through the utilization of invasive algae and waste corncobs – both of which are environmental concerns – and to measure its characteristics and anti-bacterial properties.In our production process, we extracted starch from waste corn cobs and synthesized sodium alginate from Undaria pinnatifida through the addition of acetic acid and sodium carbonate to the alginate. We then added distilled water, vinegar, and glycerin into the as-made starch and sodium alginate to form a mixture. After heating to promote polymerization, liquid biopolymer solutions were prepared. Further drying the solution, we obtained the engineered bioplastic.
The properties of our engineered bioplastic, including the biodegradation rate, strength, and melting point, were characterized and compared to cling wrap plastic. The antimicrobial effects of the bioplastic were evaluated by quantifying E. coli colony numbers on apples coated with the bioplastic.Our engineered bioplastic exhibited superior performance in biodegradation, antimicrobial function, anti-respiration, and fresh food protection as an edible coating. As compared to the 2% degradation of oxo-degradable plastics, about 68% of our bioplastic was degraded when buried in the soil for 10 days. The bioplastic had significant antibacterial properties, as the greater the concentration of the liquid bioplastic, the lower the bacterial coverage, where 80 µL of the bioplastic on a Mueller-Hinton agar plate killed almost all the E. coli bacteria. Additionally, the bioplastic slowed down the deterioration of chlorophyll in leaves as compared to the control, showing that our bioplastic slows down the dehydration and death of plants. The bioplastic can also function as an edible food coating to prolong the freshness and shelf-life of fruits. Our novel bioplastic can serve as a great alternative to petroleum-based plastics due to its biocompatibility, biodegradability, antimicrobial activity, cost-effectiveness, and environmental benefits.