The word polymer is a term that is used a lot, especially in the industry related to the production of plastic. It is a synonym for plastic or resin , the name by which it is better known among people and these substances include a wide variety of materials , each of which has its own properties. It is very common to find them in instruments or household appliances such as clothes, toys and some storage containers.
What is a polymer?
A polymer is a macromolecule that arises from the union of several small molecules or monomers that are repeated along a chain thanks to the polymerization process .
- Characteristics of a polymer
- What is it made of
- How it is formed
- Polymer types
- What is a polymer for?
Characteristics of a polymer
Polymers have several characteristics that distinguish them from other types of substances. The most important of them are mentioned below.
- They can be inorganic or they can be made up of hydrocarbons .
- They are formed from the union of monomers through chemical bonds .
- They are the result of a process known as polymerization .
- They are named taking into account the base monomer that has been used for their formation and adding the prefix ” poly ” to it .
- They are also known by the name of rubber , rubber or acrylic .
- They are not homogeneous as they have various types of molecular weights, which is known as polymolecularity.
- They are resistant to external attacks by acids , atmospheric agents or bases .
- They have the ability to withstand wear and tear and are very difficult to break.
- They have a very low density of about 0.9 g / cm³ and 1.5 g / cm³.
- They can react differently when subjected to certain temperatures .
The history of polymers comes from ancient times when materials such as wood, wool and silk were used to modify them in order to be able to obtain materials that were more resistant and useful. The first synthetic polymer was obtained in 1907 and it was thanks to Leo Hendrik Baekeland who managed to create by joining phenol and formaldehyde , a polymer he called bakelite .
The study of these materials began around the year 1922 , when Herman Staudinger established that polymers were made up of a series of long molecular chains . It was in this way that the nomenclature processes began to be carried out . After the Second World War , polymers took on even greater importance, especially synthetics
What is it made of
Polymers are formed depending on their structure by long chains of monomers which are located in a straight line.
How it is formed
They are formed through a process known as polymerization , which consists of joining the different monomers that make up the polymer through a series of covalent bonds . This type of procedure can be given in two different ways:
- By condensation : this process has the ability to form copolymer and homopolymer polymers thanks to the loss of one of its molecules at the monomer junctions. It is also known as stage polymerization .
- By addition : in this case, three different phases are needed for the process, the initiation , propagation and finally, the termination . In these phases the homolytic rupture occurs and later the monomers join.
There are several types of polymers. The types are classified depending on several criteria including:
- Natural polymers : they are produced by living organisms such as plants or animals.
- Semi synthetic polymers : they are obtained through different transformation processes from natural polymers.
- Synthetic polymers : derived from petroleum, such as plastics and nylon.
In addition, they can be classified depending on the nature of the monomers into:
- Homopolymer : when all the monomers contained in a certain polymer are identical.
- Copolymer : they are made up of two or more different monomers.
Depending on their function , there are the following types:
- Thermoplastics : they can be softened when subjected to heat and for this reason, they can also be molded. Once cooled, they can go back to a hard consistency.
- Elastomers : they are quite elastic and can regain their original shape after being exposed to some kind of deformation.
- Thermosets : they can acquire a soft consistency when they are heated for the first time, but after they are cooled they can no longer undergo a new transformation.
According to the chemical elements that make them up:
- Organic : in their main chain they contain atoms of carbon, hydrogen and also oxygen.
- Inorganic : they contain in their main chains another type of substances such as silicon and germanium .
Depending on its structure we can find the following types:
- Linear : the type of union they have is constantly repeated.
- Branched : they have a series of side chains that are linked to the main one.
- Cross-linked : they occur when neighboring chains form several links.
All polymers have a variety of different properties from each other. They are capable of having elasticity , of being reflective , they are very resistant to shocks so they can perfectly withstand strong manipulations and they are also quite hard which helps them have excellent durability . They are also very fragile and can be opaque , transparent or translucent which makes them ideal materials for working on crafts. They have a good level of malleability and also have insulating properties. They also have fragility which makes them easy to deform with heat. Some of them also have the property of having ductility which, although they are not as strong and resistant as others, makes them ideal for different purposes. Their elasticity makes them also ideal in the manufacture of cars and tires.
What is a polymer for?
There are many uses that can be given to a polymer. For example, the most natural of them found on earth is cellulose , a compound that can be found in plant cell walls and is used to make textiles and paper . Synthetic polymers , in other words those made by humans or man-made, are used to produce everyday materials such as polyethylene , which is the most common type of plastic in the world.
They are used to make plastic bags , food containers , packaging , disposable cups , bathing suits , pots , pans and many other instruments that are used both in daily life and in kitchens.
Some examples of polymers are:
- Polypropylene : used in the manufacture of fabrics for carpets and tapestries.
- Low-density polyethylene : this type of polymer can be seen in the manufacture of food bags.
- High Density Polyethylene – Found in bottles, cleaning supplies, and some children’s toys.
- Polystyrene : it is widely used for the manufacture of kitchen utensils and household products.
- Polytetrafluoroethylene : its name is almost unknown to most people but this type of polymer is what is found coating non-stick cooking pans.