POLYETHYLENE

Name: Polyethylene, PE

Real Name: Poly(methylene)

Composition: C2H4

Family: Thermoplastics

Density: 0.97

Temperature Range: -30°C/70°C

Owned by: Imperial Chemical Industrie (originally)

The discovery of polyethylene dates back to 1898, when German chemist Hans von Pechmann accidentally synthesized it by heating diazomethane. However, the material obtained at the time had no practical applications, and its potential remained unrecognized. It wasn't until 1933 when scientists Eric Fawcett and Reginald Gibson, working in the laboratories of the British company Imperial Chemical Industries (ICI), rediscovered polyethylene under high-pressure conditions. This discovery marked the beginning of its industrial production.

During World War II, polyethylene gained great strategic importance when it was used as insulation in radar cables, giving the Allied forces a crucial technological advantage. After the war, its production rapidly expanded into civilian applications due to its low cost, ease of processing, and durability. Today, polyethylene is the most widely manufactured polymer worldwide, with millions of tons produced annually and applications ranging from lightweight packaging to high-strength industrial parts.

Polyethylene stands out for a combination of properties that vary depending on its density and manufacturing method, but which generally make it a highly functional material. One of its most important characteristics is its excellent chemical resistance, as it does not react easily with acids, bases, solvents, or cleaning products, making it ideal for packaging and pipes.

Another key property is its lightness, which facilitates handling and transportation, reducing costs throughout the supply chain. Furthermore, it has good impact and abrasion resistance, which extends the lifespan of products made from this material. It is also characterized by being a hydrophobic polymer, meaning it repels water and does not absorb moisture, giving it stability even in humid environments or under adverse weather conditions.

Regarding its thermal behavior, polyethylene has a relatively low melting point compared to other engineering plastics, which allows for easy processing using techniques such as extrusion, injection molding, and blow molding. However, this same characteristic limits its use in applications requiring high temperatures.

There are different types of polyethylene depending on their density: low-density polyethylene (LDPE), flexible and widely used in plastic bags and films; high-density polyethylene (HDPE), more rigid and resistant, used in packaging and pipes; and more advanced variants such as LLDPE and UHMWPE, the latter with extremely high wear resistance.

Polyethylene's applications are virtually unlimited due to its low cost and ease of processing. In the packaging sector, it is the most widely used material for the manufacture of bags, bottles, food containers, protective films, and wrapping, thanks to its lightness, strength, and sealing properties.

In the construction industry, polyethylene plays a key role in the production of pipes, waterproofing sheets, electrical cable coatings, and insulation that protects against moisture and corrosion. Its chemical resistance makes it the ideal choice for transporting drinking water, chemicals, and fuels.

In the medical sector, certain variants of polyethylene, such as ultra-high molecular weight polyethylene (UHMWPE), are used in orthopedic prostheses, implants, and surgical components due to its biocompatibility and wear resistance.

In the automotive and heavy industry, polyethylene is used in fuel tanks, interior components, molded parts, and coatings that require lightness and strength. It is also an indispensable material in everyday consumer products such as toys, household containers, kitchen utensils, and gardening supplies.

Furthermore, polyethylene has become a key material for recycling and the circular economy. Its ability to be reprocessed and reused in new applications makes it one of the most recycled plastics in the world, helping to reduce the environmental impact of mass plastic production.