He polyurethane is a synthetic resin that occurs when condensing polyesters . The term comes from the English word polyurethane.
It should be remembered that a resin It is a pasty or solid substance that is soluble in alcohol and insoluble in water. The rating of synthetic , meanwhile, refers to its obtaining is achieved through an industrial process that mimics a natural process.
In the specific case of polyurethane, it comes from polyesters, which are resins made by polymerization of styrene (an unsaturated hydrocarbon). It is a plastic material that is distributed in various presentations, since it can be constituted as a flexible or rigid element according to its production .
The German chemist Otto Bayer He is designated as the inventor of polyurethanes in the decade of 1930 . The manufacture and use of these polymers expanded in the Second World War when to get rubber It became very difficult and expensive.
Today there are polyurethanes that are foams, sealants, adhesives or elastomers, for example. Beyond their different characteristics, there are no major chemical differences between polyurethanes, since they always arise from a reaction from diisocyanates with polyols .
Its rigidity or flexibility, in this context, is given according to the class of diisocyanates and polyols used. The density , for its part, depends on the expansion agent that is used in the production process.
Polyurethanes are used to create mattresses , clothes, shoes and seats, to mention just a few possibilities. It should be noted that most refrigerators (also called refrigerators, refrigerators or refrigerators) use polyurethane as isolating material .