What is the structure of polystyrene?
Polystyrene structure
Chemically, polystyrene is a long-chain hydrocarbon in which variable carbon centers are attached to phenyl groups (the name given to cyclic benzene). The chemical formula of polystyrene (n) is C8H8; this material contains moles of the chemical elements carbon and hydrogen.
The properties of the material are determined by the short-term van der Waals adsorption between the polymer chains. Since molecules are long-chain hydrocarbons made up of thousands of atoms, the overall attractive force between molecules is large. Upon heating (or rapidly deforming due to the combination of viscoelastic and thermal insulating properties), the chains become more conformable and slide past each other. This intermolecular slackness (in contrast to the high intermolecular strength due to hydrocarbon persistence) gives flexibility and elasticity to this material. The ability of the system to deform at a temperature higher than its glass transition temperature allows polystyrene (and heat-softening polymers in general) to easily soften and form gonacones when heated.
History
Polystyrene was first discovered by Edward Simon in 1839, who did not know what a valuable substance she had discovered. The commercial preparation of styrene monomer and its polymerization dates back to 1934, when the Dow company was able to synthesize styrene from petroleum products and then polymerize it. At the same time, this process is completing its stages in West Germany. At the same time, this process is completing its stages in West Germany. With the passage of time and with the publication of various theories (including Hermann Staudinger’s theory in 1922 about polymer), BASF finally developed a two-step process for the production of polystyrene foam in the early 1950s. In this process, the first step includes the preparation of grains containing a uniform distribution of the foaming agent by the suspension polymerization method of styrene monomer, and in the second step, this material is processed inside a mold. The ease of producing products in any shape and size is one of the advantages of this method, which led to its development. This material was first produced in 1950.
Ordinary polystyrene
Polystyrene with the abbreviation GPPS, which is used for general purposes, should usually have properties such as good heat resistance, good impact strength, and good fluidity during the process. Polystyrene with the abbreviation GPPS, which is used for general purposes, should usually have properties such as good heat resistance, good impact strength, and good fluidity during the process. The brand name of this product in the Iranian market is Crystal.
Indications
To produce disposable containers, electronic devices, clock bodies, televisions, radios, sports equipment, toys, cold insulation in the body of refrigerators, freezers and household appliances.
Resistant polystyrene
This type of polystyrene with the abbreviation high-impact polystyrene (HIPS) is resistant to impact and for this reason it is used in making containers and the body of household appliances. The brand name of this material in the Iranian market is Hypek.
Indications
For the production of sports equipment, toys, cold insulation in the body of refrigerators, freezers and household appliances and disposable containers
Expanded polystyrene (Unolit)
This type of polystyrene with the abbreviation Expanded polystyrene (EPS) is a type of white polymer to which a foaming agent has been added; which is known as Yunolit in Iran.
Indications
To produce ceiling plastofoam blocks to be used as sound and thermal insulation in different buildings and places.
Cold insulation in cold stores and industrial refrigerators.
Making all kinds of packaging foams and all kinds of refrigerators and thermoses.
Features of EPS ceiling plastofoam light block
Production of ceiling plastofoam blocks
The new ceiling block is made of expanded polystyrene material and is the best alternative to cement and clay blocks.
Features of EPS ceiling plastofoam light block
1- lightness
2- The speed and ease of implementing the roof
3- Stable against earthquakes: Due to the reduction of dead load, it is more stable against earthquakes and does not crumble during earthquakes.
4- Saving plaster and soil: For the first time, grooves are created on the lower side of the mentioned block and it is placed under the roof.
5- Saving on hardware: It is reduced by 22% per square meter.
6- Shockable
7- Fast and easy transportation
8- Reduction of 15 tons of weight per 100 square meters
9- High speed in implementation and reduction of salary costs
10- saving on concrete roof beams so that the center distance of the concrete beam can be changed from 50 cm to at least 60 cm
Producer complexes and products
Different grades of expanded polystyrene
Unolith (EPS) grades are usually based on particle size and type of surface coating. Of course, there are special grades of it such as slow burning (F) and antistatic.
Related complexes in Iran
In Tabriz Petrochemical, products are produced in different grades. In Baniarganbad Petrochemical, products in grades F-1000, F-2000, F-3000 and Petromel in grades F50. F100. F150. F250. F350. F22. F16 is produced.
