Post by account_disabled on Mar 15, 2024 23:30:28 GMT -6
If you look around you, you will surely notice at least some plastics in your environment, although you may not realize that they are made of polymers. What are polymers? Examples and applications of these popular substances can be found below. Published: 09-07-2023 What are polymers? Polymers are a specific type of chemical substances that are characterized by their high molecular weight . Furthermore, they have a specific structure: they consist of repeating units called mers . The high molecular weight means that the detachment or attachment of a single mer does not significantly alter the chemical and physical properties of the compound. This is an important difference with oligomers (substances made up of a small number of groups): in their case, such a change can cause, for example, a different melting point. Polymers are mainly associated with plastics . However, in reality this group of compounds is much broader. In addition to synthetic polymers , which are the basic components of plastics, there are also natural polymers , which are common in nature. They are one of the basic components of living organisms. Chemical properties of polymers. Each polymer can have its own individual properties. It is possible, however, to distinguish several chemical properties of polymers that are common to all of them. These are the following: Resistance to chemicals. For example, the plastics used for packaging do not react with the chemicals they contain. Electrical and thermal insulation.
Polymers are good insulators. The materials used for the protective layers of cables or for power sockets are produced from them. Their heat resistance properties allow these materials to be used in the home, for example in pot handles. High resistance and at the same time light . Some plastics can even float. Easy to process . Polymers can be processed in various ways: they can be formed into thin layers (e.g. textile fibers) and solid structural structures. They can be easily formed into a specific shape. How are polymers produced? The production of polymers can be done by one of two CZ Leads methods: polymerization and polycondensation. In the first process, a chain reaction takes place in which the monomers join together. This is not accompanied by the formation of byproducts. For polymerization to occur, it is necessary to use an initiator, a substance that starts the reaction and in which it is consumed. The linking monomers can originally be found in solid, liquid or gas phase. Plastics resulting from polymerization include: LDPE and HDPE polyethylene , polyvinyl chloride (PCV) , polypropylene (PP) , polystyrene (PS). Polycondensation produces a macromolecule, that is, a polymer, and as a byproduct another substance, such as water, ammonia or hydrogen chloride . In this reaction, the polymer chain grows step by step.
Among the most popular plastics produced by polycondensation are: polyamides, phenol-aldehyde resins, epoxy resin, certain polyesters . In the later stages of plastics production, various types of additives, such as stabilizers or modifiers, are often necessary. With them it is possible to produce materials with specific properties. You can find a wide range of additives for plastics in the PCC Group portfolio, which is available on the Product Portal . What types of polymers exist? All polymers can be divided according to several criteria, for example by their origin, structure and shape and arrangement of their molecules. Depending on their origin, polymers can be: synthetic , that is, they are produced entirely by chemical synthesis from monomers; natural , that is, they are produced by living organisms; these include, for example, cellulose , proteins or nucleic acids; natural but modified through chemical reactions, for example, cellulose acetate or modified starch are modified polymers . Different types of polymers can also be distinguished based on their chain structure. There are, among others, linear, branched, ladder or cross-linked polymers. Additionally, polymer molecules can have unusual shapes, similar to links in a chain or a tree. Another classification is based on the number of different groupers in a chain. If the chain is made up of only one type of mers, it is a homopolymer . If there are two or more of them, such compounds are called copolymers . Most polymers are organic compounds.