Around us there are countless products made of plastic in part or in full.
In general, a plastic is a flexible, durable, lightweight and insulating material from electricity and heat. It is widely used in industry because it is easy to manufacture and model, is economical, lightweight and supports pigments of a wide variety of colors. In addition, it can be combined with other materials and thus improve its properties.
1.-ORIGIN AND PRODUCTION OF PLASTIC
A plastic is a material that is made up of large molecules (macromolecules) that become entangled in a chain. Plastics are also known as polymers, because the molecules of any plastic are composed by the union of many smaller, simpler molecules that repeat, forming chains that entangle with each other, which create a network. These simplest molecules, which combine together, are called monomers, and the union of many monomers forms a polymer, that is, a plastic ("poly" means "many", so "polymer" means "many monomers. ”).
Although natural plastics, such as cellulose and rubber, do exist, the vast majority of plastics are synthetic materials. They are obtained from raw materials such as oil, coal or natural gas. Although the vast majority are basically extracted from oil. There are many industrial and complicated methods of plastic manufacturing. The obtained plastic material can be shaped into pellets, granules or powders, which are then processed and molded into final sheets, tubes or pieces of the object.
It is difficult to generalize on the properties of plastics due to the wide variety of plastics that exist. We will study the most significant, all of which share:
Null electrical conductivity. Plastics misconduct electricity, which is why they are used as electrical insulators; we see it, for example, in the coating of cables.
Low thermal conductivity. Plastics usually transmit heat very slowly, which is why they are often used as thermal insulation; for example, on the handles of the kitchen batteries.
Mechanical resistance. Although the plastics are very light, they are very resistant. This explains why they are used next to metal alloys for building aircraft and why almost all toys are made of some kind of plastic.
Fuel. Most plastics burn easily because their molecules are made of carbon and hydrogen. The color of the flame and the smell of the smoke they emit are usually characteristic of each type of plastic.
In addition, we can highlight the economical ones, which are, with the exception of, the simplicity of their manufacturing techniques and the ease they have. to be combined with other materials. Therefore, it is possible to create composite materials with better properties, such as fiberglass reinforced polyester.