By: Joyce Wu Y10 Peace
The “normal” plastic products that we use everyday (such as plastic bags, plastic food packaging, plastic eating utensils etc.) are manufactured from non-renewable sources (coal, oil and natural gas). These plastics are non-degradable and take more than hundreds of years to break down in landfills, while 29 billion tonnes of this non-degradable plastic waste are dumped into those landfills every year worldwide! [Recyclaholics: The Facts] That plastic waste doesn't just take up loads of space; it also releases methane, a greenhouse gas that is 23 times as harmful as carbon dioxide as a contributor to global warming! [Recyclaholics: The Facts] Therefore, these non-degradable plastic products are causing a giant environmental problem nowadays. The usage of biodegradable plastic can solve this problem, because these plastics can biodegrade in about 2-3 months when composted properly. [Pays to Live Green]
Biodegradable plastics were actually invented in 1869 by the American inventor John Wesley Hyatt (to coat billiard balls) before today’s synthetic plastics were made. The first biodegradable plastics were made with cellulose, which is an organic compound with the formula (C6H10O5)n that is contained in the primary cell wall of many green plants [Cellulose]. In the 1930s, Henry Ford even produced biodegradable plastic car parts using soybeans! [Who Invented Bio-Plastics? A Brief History of Biodegradable Plastic] Nowadays, there are many kinds of biodegradable plastic, including polyesters, polyhydroxybutyrates, vinyl polymers and starch-based polymers. [Garthe, James W., and Paula D. Kowal] In this essay, the use of plastic made from polylactic acid or PLA (a kind of starch-based polymer) will mainly be discussed, because they are one of the most commonly used and cheapest-costing of all biodegradable plastics.
PLA is made from the starch in corn (or sometimes wheat) plants,...