I have chosen to go into the field of Sustainability Management through a program offered at University of Wisconsin. Sustainability is important to me because I feel that we, as a race, and especially as a country, we are extremely wasteful. We are taught to be consumers from the time we can open our eyes. Everywhere we look there is an advertisement for one thing or another; bright, happy pictures selling everything; up-beat jingles stuck in our heads; celebrities endorsing a variety of products. As a person, we think that all of these products will make us a “happy” or “better” person…and it might for a short period, until the next new thing comes around the corner and we rush to upgrade. Our lives and our world have become littered by all these materials; some of which are natural products, but the majority are synthetic, or man-made, and are not easy to dispose of. According to the Mother Nature Network, 60% of the trash that we throw away can actually be recycled, but only about 13% is (Moss, 2011). Of this massive amount of garbage, about 30 million tons of that is some form of plastic (Science Channel, 2011).
What happens to all those unused or discarded products? Unfortunately they do not vanish into thin air: The First Law of Thermodynamics (or the Law of Conservation of Matter) states that matter/energy cannot be created nor can it be destroyed. The quantity of matter/energy remains the same; it may change form, but the total amount of matter/energy in the universe remains constant (Second Law of Thermodynamics). We have come quite a long way in science and sustainability and have managed to merge these two concepts together. So, my topic of discussion is to understand how chemistry assists with the decomposition of plastics:
How does chemistry help with the breakdown of biodegradable material? What chemical processes occur in the degradation of biodegradable and photodegradable plastics?
What is plastic?
Look around you. Plastic is everywhere! It is used in making your computer you are working on, the highlighter or pen you are using, your cell phone, your lamp, TV set, toothbrush, your binders you use for school, the cup you are drinking out of, the packaging of the new toy you just bought, the container you use to store your leftovers in…plastic is in every room of your home and you probably never recognized it. So what is plastic made of and how is it so diverse?
Plastic is made of small organic molecules, monomers, which contain carbon and are typically made from petroleum or natural gas. Some organic materials, biopolymers, such as wood fibers, corn or banana peels, can also be used to make to make plastics. Monomers are molecules that form the basic unit for polymers. Polymers are these monomers that are bound together to form a repeating chain molecule through a chemical reaction called polymerization [see picture, (Simple Science - Polymers)]. A catalyst is a substance that increases the rate of a chemical reaction without itself undergoing a permanent chemical change, and is combined with the monomers to begin the polymerization process. While this chemical reaction is underway, the monomers are combining to form the polymer chains. Millions of these chains can be formed at the same time. These large sums of polymer chains create a substance called resin. Resin is then sold in the form of powder, tiny granules, or pellets to a manufacturer. The manufacturer will then modify the resin to create his end product, for example, a grocery bag or plastic bottle (Plastics and Polymers, 2007).
Plastic can come in many different forms and used to make many different products. Below are a few examples of different forms of plastics and their uses (Lower, 2009): * Polycarbonate is very hard and strong and is used to make items CD’s, dome lights, and even bullet-proof glass. * Polyethylene terephthalate (PET) is used for food packaging, weather balloons, and