Polyethylene or polyethylene is one of the simplest and cheapest polymers. Solid polyethylene is waxy and inactive. This material is obtained from ethylene polymerization and is abbreviated as PE. In the process of polymerization, the double bond of each of the monomers is broken, and instead a simple bond is formed between the carbon atoms of the monomers, and the product is a large molecule. History of polyethylene production Polyethylene was first synthesized by the German chemist Hans Von Pechmanv. In 1898, while heating the de Azumotan, he synthesized a white waxy compound called polyethylene. The first industrial synthesis of polyethylene was accidentally discovered by Ezekiel Noste and Rinollergison (ICI chemists) in 1933. The two scientists obtained a wax-like substance by heating a mixture of ethylene and benzaldehyde at high pressure. The reaction was due to the presence of oxygenated impurities in the devices used as the starting material for polymerization. In 1935, Michael Perrin, another ICI scientist, developed this method and synthesized polyethylene under high pressure, which became the basic method for the industrial production of LDPE in 1939. Use of catalysts in the synthesis of polyethylene An important event in the synthesis of polyethylene was the discovery of several new catalysts that made ethylene polymerization possible at a milder temperature and pressure than other methods. The first catalyst discovered in this field was chromium trioxide, which was discovered in 1951 by Robert Banks and John Hussen at Philips Teprolium. In 1953, German chemist Carl Ziegler developed catalytic converters including titanium halides and aluminum alloys. These catalysts could be used in milder conditions than Philips catalysts and also produced a polyethylene arrangement (with a regular structure). The third type of catalytic converter system was the use of metallic compounds, which was developed in Germany in 1976 by Walter Caminiki and Hans Zhoujin. Ziegler and Metallusan catalysts are highly functional and are used in the ethylene copolymerization process with other olefins, which are the basis for the production of important polymers such as VLDPE, LLDPE, and MDPE. Recently, a high-usability catalyst family has been developed for polymerization of polyethylene called zirconocon dioxide, which allows the production of high-crystalline (single-arrangement) polymer. There is also another type of catalyst called the immunoglobulin complex with metals of the sixth group, which has a higher performance than metallurgy. Types of polyethylene The classification of polyethylene is based on their density, which depends on the amount of density of the polymer chain and the type and number of branches in the chain. High Density Polyethylene (HDPE) This polyethylene has branchless polymer chains, so the intermolecular force in the chains is high and its tensile strength is higher than other polyethylene. The reaction conditions and the type of catalyst used are effective in the production of HDPE polyethylene. For the production of branched polyethylene, the polymerization method with Ziegler-Nata catalyst is usually used. Low density polyethylene (LDPE) This polyethylene has branched chains, so LDPE chains cannot bond well with each other and have poor intermolecular strength and lower tensile strength. This type of polyethylene is usually produced by radical polymerization. The polymer is characterized by flexibility and the ability to decompose by microorganisms. Low Density Linear Polyethylene (LLDPE) This polyethylene is a linear polymer with a number of short branches and is usually formed by the copolymerization of ethylene with long chain alkenes. MDPE Polyethylene is of medium density. Application Polyethylene is widely used in the manufacture of a variety of plastic appliances used in the kitchen and food industry. LDPE is used in the production of light plastic containers as well as plastic bags. HDPE is used in the manufacture of milk and liquid containers and a variety of plastic kitchen utensils. MDPE is commonly used in the manufacture of plastic pipes and plumbing fittings. Due to the high degree of flexibility, LLDPE is used in the production of a variety of flexible plastic devices, such as bendable pipes. Recently, a lot of research has been done on the production of long-chain polyethylene with short branches. These polyethylene are essentially HDPE with a number of side branches. These polyethylene have a combination of HDPE strength and LDPE flexibility. Please contact us for more information.