This section contains the information on the main brands of polyamides which we produce.
The materials we offer differ on physical and mechanical properties, use conditions, methods of processing and can be applied in various industrial areas.
History of polyamides
Polyamides represent a class of high-molecular compounds, huge on number of representatives and very important on its scientific and practical value.
Nearly one and a half centuries have passed since the date of receiving the first synthetic polyamide by Harbordt in 1862. They represent the history of continuous scientific development in this sphere which results in ever-widening practical applications.
In the modern industry polyamides are of enormous significance. That is confirmed by the fact that their world production is estimated in hundreds of thousands of tons and increases continuously.
In the production scale polyamides are high on the list among synthetic high-molecular polymers.
The range of the materials made of different types of polyamides is huge. It includes not only synthetic fibers widely used for production of textile products of household and technical purpose but also various molding and films.
On the example of polyamides it was established for the first time that linear polymers of a certain molecular weight are capable to form fibers. The first synthetic fibers of practical value were received from polyamides. Polyamide fibers are distinguished by extremely high durability and take the first place in the production scale among all other synthetic fibers.
At the present time the chemistry and the physics of polyamides take a large section in the science on high-molecular compounds. At the first stage of development of the chemistry of high-molecular compounds their features were studied on cellulose generally. Now these researches are conducted with wide use of polyamides.
The main regularities of polycondensation and polymerization of cyclic compounds were mainly established at producing polyamides. Orientation and crystallization of polymers were widely studied on the example of many polyamides.
Polyamides are widely spread in the nature. These are various proteins and other numerous biologically important substances which are found in organisms of animals and plants.
The first synthetic polyamide was received by Harbordt in 1862. Exposing m-aminobenzoic acid to the action of chlorine hydride at 200 °C he separated the powder of gray color, not soluble in alkalies and acids except for the concentrated sulphuric acid. In the sulphuric acid this product was highly soluble and settled out when water was added to the solution. Thus the poly-m benzamide, the first representative of synthetic polyamides, was received.
In 1881 Michler and Zimmerman received polyphenylene urea at saturation the solution of m-phenylenediamine in chloroform with phosgene. At the present time this reaction is widely applied in interfacial polycondensation.
КIn 1888 for the first time Curtius and Goebel separated polyamides at polycondensation of a-amino acids esters.
In 1889 the polyamides known under the name of carbamide or urea formaldehyde resin were synthesized by polycondensation of urea with formaldehyde. Soon these products gained enormous practical value and already in the twenties of our century the industrial production of carbamide resins began. Thus, carbamide resins are the first representatives of polyamides, and their production plays a large role in plastics industry till up to the present.
In 1899 for the first time poly-e-caproamide (polycaprolactam) was received by Gabriel and Maas at e-amino caproic acid polycondensation. At that they observed that heating of e-amino caproic acid led to formation of low-molecular cyclic product – e-caprolactam – along with polymer.
Afterwards poly-e-caproamide played a huge role in development of the industry of synthetic fibers – it is widely applied as a raw material at fiber production. It began after Schlack revealed in 1938 that e-caprolactam is capable to be polymerized when heating with water forming at that a high-molecular polymer. On the basis of this polyamide the synthetic fiber was developed which has received the name "perlon" or "kapron".
In 1906 Leuhs synthesized compounds of a new class – N-carban-hydrides of a-amino acids from which it became possible to receive synthetic polypeptides with a big molecular weight.
In 1935 Carothers synthesized poly hexamethylene adipamide by polycondensation of hexamethylenediamine with adypic acid. From this polyamide the first synthetic fiber was received.
Especially rapid development of researches on synthesis and use of polyamides began after Carothers's work on synthesis of polyamides from various diamines and dicarboxylic acids. Carothers showed that strong fibers can be received from the polyamides synthesized by him by extract from the melted resin. In 1938 in the USA the production of synthetic fiber from poly hexamethylene adipamide started which became known in the world under the name "nylon". At the present time nylon-66 takes the leading place among all synthetic fibers and the scale of production of this fiber is estimated in hundreds of thousands of tons.
At the end of 1939 in Germany the production of perlon fiber started. Then the production of polyamide fibers began in other countries.
Polyamides represent high-molecular compounds of linear structure with molecular weight up to 30 thousand. Macromolecules consist of flexible methylene chains with polar amido groups regularly located along a chain.
Existence of the amido groups capable to form hydrogen bonds defines physical and chemical properties which are general for all polyamides.