Plastic is made from gas and oil, all of which come from plants. So why plastic?
Yael Vodovots, a professor of food science and technology at Ohio State University, explained why plastic does not biodegrade.
Plastic is made from oil and gas.Oil is considered a fossil fuel. This means that it consists of the remains of old living organisms: bacteria, algae, plants. All of them were once deep underground, and after millions of years they turned into fuel.
There is also a lot of propylene in oil.To create plastic, propylene and a catalyst (that is, a substance that accelerates chemical reactions) are used. As a result, propylene molecules begin to adhere to each other. One such chain containing many molecules is called a polymer.
If some biodegradable material (for example, a cardboard box), then microorganisms digest the polymers that are in this material. This is done with the help of special enzymes.
The problem is that there are few polymers like propylene in nature. Therefore, microorganisms that break down materials simply cannot recognize the bonds that hold these polymers together.
For the same reason, purely theoretically, polymers inplastic can only break down after hundreds of thousands of years. But during this time, plastic objects can already release harmful substances into water and soil. Plastic also breaks down into tiny pieces that fish, birds and other animals eat.