The use of plastics is forever increasing from the days in which it was first invented. Not only does plastic now replace materials such as metal, glass, ceramics, wood, and paper in a wide variety of ways, there are new roles which only plastic can fill. .
Plastics are polymers. These are large, long molecules constructed of smaller, shorter molecules called monomers. Polymers can be natural or synthetic. Natural polymers are common in animals and plants, such as with proteins in animals and carbohydrates in plants. Synthetic polymers however, are made mainly from petroleum. This is processed in an oil refinery to produce basic chemicals known as monomers. The monomers are then turned into polymers. Some polymers are turned into solid plastic materials and others into textile fibers. .
Plastic was first made in 1869 when John W. Hyatt created celluloid (Dorin et al. 64). It was used to make objects such as ornaments, knife handles, cuffs, collars, and film for movies. Today, there are over seven hundred different types of plastic used to produce both hi-tech and everyday objects. .
The raw material for plastics is crude oil, a complex mixture of thousands of compounds. In order to be useful, it must be processed. Approximately four percent of the world's production of crude oil is turned into plastic, while roughly, forty-two percent is used for heating and electrical energy, forty-five percent is used for transportation, and the rest is used for other uses (Carey 216).
The compounds in crude oil have different masses, and therefore boil at different temperatures. Thus, it is possible to separate them by a process known as fractional distillation. The mixture is separated into fractions, not individual compounds. The fractions contain a mixture of compounds that have similar boiling temperatures. It is mainly the naphtha and gas oil fractions that are used for further processing to make plastic.