Meaning of Plastic
What is Plastic:
Plastic is a material of organic origin with high molecular weight, and it is characterized by its malleable property that allows it to adopt a variety of shapes. The word plastic derives from the Greek plastikos, which means "moldable".
Plastic is made up of long chains of large molecules called polymers, which undergo the chemical polymerization process, and is obtained from chemical derivatives of oil and natural gas.
Plastic molecules are of organic origin, for example, resin, rubber or cellulose, among others, which can be molded into various shapes and permanently after being at high temperatures, and carry out a compression process , molding or spinning.
For the manufacture of the finished plastic, resin in powder or small pellets is mainly used. As a result, bottles, tubes, containers, fibers and a great variety of objects that we use in our day to day are made.
Due to its versatility and resistance, plastic has become one of the most used materials and, even, one of the most polluting, since it can be non-recyclable or biodegradable and its incineration greatly affects the ozone layer and the environment. in general.
History of plastic
The use of polymers dates back to ancient Mesoamerican cultures. However, it was in 1860 that the first plastic was made, when John Haytt developed celluloid.
Then in 1909 Leo Baekeland, a Belgian chemist, created the first synthetic plastic, resistant to water, solvents and did not conduct electricity.
Scientists continued with plastic research and in 1920 Hermann Satudinger was the first to synthesize polystyrene and explain what polymerization consists of. In 1933, chemists Reginald Gibson and Eric Fawcett created a thermoplastic called polyethylene.
Then, in the following decades, scientists continued to investigate plastic and polytetrafluoroethylene or Teflon, polystyrene, the artificial fiber known as nylon, polypropylene, among others, appeared.
See also Polymer.
There is a wide variety of plastics that can have particular or common properties. The main properties of plastic are mentioned below:
- It is not a conductor of electricity, so it is a good electrical insulator.
- It is a thermal insulator, although it does not withstand very high temperatures.
- It works as an acoustic insulator.
- It has a high combustibility because it is largely composed of carbon and hydrogen.
- It has a high mechanical resistance.
- It has a high chemical resistance, so it prevents corrosion and other chemical factors that alter some materials.
- They are waterproof.
- They have low density.
- They enjoy having plasticity when softened in heat.
- Its preparation is not expensive.
- Some plastics cannot be easily recycled.
Types of plastic
Plastics can be classified into three types: thermoplastics, thermosets, and elastomers.
It is the most widely used plastic. It is characterized by being a plastic that deforms at room temperature and can melt at high temperature and transform into a liquid that hardens when cooled. This is possible because its macromolecules are free.
Thermoplastics are polyethylenes, polyesters, polystyrenes, polypropylenes, polyvinyls and saturates. For example, bags, bottles, food containers, electrical insulators, boxes, among others.
These plastics, once they have gone through the process of forming a closed mesh of macromolecules, are transformed into a rigid plastic, and its shape cannot be changed again.
As thermosets, mention may be made of phenols, animas, polyester resins, epoxy resins, melamine resins, aminoplastics and bakelite. For example, electrical insulators, sports equipment, swimming pools, among others.
They are plastics with great elasticity and rebound without losing their initial shape and dimension when a force acts on them. Rubbers, polyurethanes, silicones, among others, are part of this type of plastic. For example, tires, prostheses, diving suits, among others.