It is amazing how diverse the objects and materials surrounding us are made of. Earlier, around the XV-XVI centuries, the main materials were metals and wood, a little later glass, almost at all times porcelain and faience. But today's century is the time of polymers, which will be discussed further.
The concept of polymers
Polymer. What it is? You can answer from different points of view. On the one hand, it is a modern material used for the manufacture of many household and technical items.
On the other hand, it can be said that this is a specially synthesized synthetic substance obtained with predetermined properties for use in a wide range of specializations.
Each of these definitions is correct, only the first from the point of view of household, and the second from the point of view of the chemical. Another chemical definition is as follows. Polymers are macromolecular compounds based on short sections of a molecule’s chain — monomers. They are repeated many times, forming a macrochain of the polymer. Monomers can be both organic and inorganic compounds.
Therefore, the question: "polymer - what is it?" - requires a detailed answer and consideration for all the properties and fields of application of these substances.
Types of Polymers
There are many classifications of polymers according to various criteria (chemical nature, heat resistance, chain structure, and so on). In the table below, we briefly consider the main types of polymers.
Polymer Classification| Principle | Kinds | Definition | Examples |
| By origin (occurrence) | Natural (natural) | Those that are found in natural conditions, in nature. Created by nature. | DNA, RNA, proteins, starch, amber, silk, cellulose, natural rubber |
| Synthetic | Obtained in the laboratory by man, are not related to nature. | PVC, polyethylene, phenol-formaldehyde resins, polypropylene, polyurethane and others |
| Artificial | Created by man in the laboratory, but based on natural polymers. | Celluloid, cellulose acetate, nitrocellulose |
| In terms of chemical nature | Organic nature | Most of all known polymers. It is based on a monomer of organic matter (consists of C atoms, the inclusion of N, S, O, P atoms and others is possible). | All synthetic polymers |
| Inorganic nature | The basis is constituted by such elements as Si, Ge, O, P, S, H and others. Polymer properties: they are not elastic, do not form macrochains. | Polysilanes, polydichlorophosphazene, polygermans, polysilicic acids |
| Organoelement nature | A mixture of organic and inorganic polymers. The main chain is inorganic, the side chains are organic. | Polysiloxanes, polycarboxylates, polyorganocyclophosphazenes. |
| Main Chain Difference | Homosexual | The main chain is either carbon or silicon. | Polysilanes, polystyrene, polyethylene and others. |
| Hetero chain | The main skeleton of different atoms. | Polymers examples are polyamides, proteins, ethylene glycol. |
Also distinguish polymers of linear, mesh and branched structure. The basis of polymers allows them to be thermoplastic or thermosetting. They also have differences in their ability to deform under ordinary conditions.
Physical properties of polymeric materials
The main two states of aggregation characteristic of polymers are:
Each is characterized by its own set of properties and has important practical significance. For example, if a polymer exists in an amorphous state, then it can be a viscous fluid, a glass-like substance, and a highly elastic compound (rubbers). This is widely used in chemical industries, construction, engineering, and industrial goods.
The crystalline state of the polymers are quite arbitrary. In fact, this state is interspersed with amorphous parts of the chain, and in general the whole molecule is very convenient for obtaining elastic, but at the same time high-strength and hard fibers.
Melting points for polymers are different. Many amorphous ones melt at room temperature, and some synthetic crystalline ones withstand quite high temperatures (plexiglass, fiberglass, polyurethane, polypropylene).
Polymers can be painted in a variety of colors, without restrictions. Due to their structure, they are able to absorb paint and acquire the most vivid and unusual shades.
Chemical properties of polymers
The chemical properties of polymers differ from those of low molecular weight substances. This is explained by the size of the molecule, the presence of various functional groups in its composition, and the total supply of activation energy.
In general, several main types of reactions characteristic of polymers can be distinguished:
- The reactions to be determined by the functional group. That is, if the OH group, which is characteristic of alcohols, is included in the polymer, it means that the reactions they will enter will be identical to those of alcohols (dehydration, oxidation, reduction, dehydrogenation, etc.).
- Interaction with NMS (low molecular weight compounds).
- Polymer reactions with each other with the formation of crosslinked networks of macromolecules (network polymers, branched).
- Reactions between functional groups within the same polymer macromolecule.
- The decomposition of a macromolecule into monomers (chain destruction).
All of these reactions are of great importance in practice for producing polymers with predetermined and convenient human properties. Chemistry of polymers allows you to create heat-resistant, acid and alkali-resistant materials with sufficient elasticity and stability.
The use of polymers in everyday life
The use of these compounds is widespread. Few can recall areas of industry, the national economy, science and technology in which a polymer would not be needed. What is polymeric economy and widespread use, and how is it exhausted?
- Chemical industry (plastics, tannins, synthesis of the most important organic compounds).
- Engineering, aircraft, oil refineries.
- Medicine and pharmacology.
- Obtaining dyes and explosives, pesticides and herbicides, agricultural insecticides.
- Construction industry (steel alloying, sound and heat insulation structures, building materials).
- Making toys, dishes, pipes, windows, household items and household utensils.
Chemistry of polymers allows you to get more and more new, completely universal in properties materials, equal to which there is neither among metals nor among wood or glass.
Examples of products from polymeric materials
Before you name specific products from polymers (it is impossible to list them all, their diversity is too great), first you need to figure out what the polymer gives. The material that is obtained from the Navy will be the basis for future products.
The main materials made from polymers are:
- plastics
- polypropylene;
- polyurethanes;
- polystyrenes;
- polyacrylates;
- phenol formaldehyde resins;
- epoxy resins;
- caprons;
- viscose;
- nylons;
- polyester fibers ;
- adhesives;
- films;
- tannins and others.
This is just a small list of the variety that modern chemistry offers. Well, here it’s already becoming clear what objects and products are made from polymers - almost any household items, medicine and other areas (plastic windows, pipes, dishes, tools, furniture, toys, films, etc.).
Polymers in various fields of science and technology
We have already touched on the question of in which areas polymers are used. Examples showing their importance in science and technology include the following:
- the use of rubber ;
- antistatic coatings;
- electromagnetic screens;
- cases of almost all household appliances;
- transistors
- LEDs and so on.
There are no restrictions on the imagination of the use of polymeric materials in the modern world.
Polymer production
Polymer. What it is? This is almost everything that surrounds us. Where are they produced?
- Petrochemical (oil refining) industry.
- Special plants for the production of polymeric materials and products from them.
These are the main bases on the basis of which polymer materials are synthesized.