Polymers are macromolecules formed from smaller structural units (monomers). The term "polymer" comes from the Greek and means "many parts". They are of great importance for life on the planet, since DNA, proteins and polysaccharides are examples of natural polymers. In addition, many materials that we use on a daily basis, such as plastics, rubbers and fibers, are synthetic polymers.
Polymers can be classified in several ways, one of them is the classification according to the origin, which can be natural or synthetic. Natural polymers, as the name suggests, are found in nature and include DNA, cellulose, latex, among others. Synthetic polymers, on the other hand, are produced in the laboratory and include plastics, synthetic rubbers, synthetic fibers, among others.
Another important classification is related to structure. The polymers can be linear, branched or crosslinked. Linear polymers are formed by a single chain of monomers, while branched ones have side chains. The reticulates, in turn, have a three-dimensional structure, with covalent bonds between the polymeric chains.
Polymers can also be classified according to their thermal behavior, and may be thermoplastics, thermosets or elastomers. Thermoplastics are polymers that can be molded when heated and harden when cooled, and can be reprocessed many times. Thermosets, on the other hand, once molded and heated, cannot be reprocessed as they form a rigid three-dimensional structure. Elastomers are polymers that have great elasticity, rubber being a classic example.
Polymers are formed through polymerization reactions, which can be addition or condensation. In addition polymerization, monomers add to each other without removing any molecules. In condensation polymerization, however, there is the elimination of a small molecule, such as water.
It is important to mention that polymers have a wide variety of applications. They are used in the manufacture of plastics, rubbers, fibers, adhesives, paints, among others. In addition, they have applications in medicine, such as in the manufacture of prostheses and implants, and in biotechnology, such as in the production of biofilms and the controlled release of drugs.
Finally, it is worth noting that polymers, despite their numerous advantages, also bring challenges to society. One of the main ones is the improper disposal of synthetic polymers, which are resistant to decomposition and can cause environmental problems. Therefore, it is essential to raise awareness about the importance of recycling and the responsible use of these materials.
In summary, polymers are macromolecules of great importance for life and society. They are formed from monomers and have a wide variety of properties and applications. However, responsible use and recycling are key to minimizing the environmental impact caused by these materials.
