Most plastics come from chemicals in crude oil. However as the world’s a reserve of crude oil begin to run out; coal and gas are now being used more frequently. At a refinery, crude oil is separated into different fractions or chemicals. Most of these fractions are used for fuels.
In a further process at the refinery some of the remaining fractions are cracked or separated into various parts, including the gas ethylene, one of the main chemicals from which plastics can be made.
Plastic is a word that originally meant “pliable and easily shaped.” It only recently became a name for a category of materials called polymers. The word polymer means “of many parts,” and polymers are made of long chains of molecules. Polymers abound in nature. Cellulose, the material that makes up the cell walls of plants, is a very common natural polymer.
Over the last century and a half humans have learned how to make synthetic polymers, sometimes using natural substances like cellulose, but more often using the plentiful carbon atoms provided by petroleum and other fossil fuels. Synthetic polymers are made up of long chains of atoms, arranged in repeating units, often much longer than those found in nature. It is the length of these chains, and the patterns in which they are arrayed, that make polymers strong, lightweight, and flexible. In other words, it’s what makes them so plastic.
These properties make synthetic polymers exceptionally useful, and since we learned how to create and manipulate them, polymers have become an essential part of our lives. Plastics have saturated our world and changed the way that we live.
Picture Credit : Google