Polypropylene (PP) is a thermoplastic polymer used extensively in various applications due to its unique properties. Known for its resilience to chemical and physical stresses, PP is lightweight, resistant to fatigue, and has a high melting point, making it ideal for use in packaging, textiles (like ropes, thermal underwear, and carpets), automotive components, and reusable containers. Its versatility is further enhanced by its ability to be modified or copolymerized, which allows for a wide range of mechanical and thermal properties. Polypropylene is also appreciated for its sustainability aspect, as it is recyclable, contributing to reduced plastic waste and promoting circular economy practices in the plastics industry.

Low-Density Polyethylene (LDPE) was discovered in 1933 by two English chemists, Reginald Gibson and Eric Fawcett, while working at the Imperial Chemical Industries (ICI) research laboratory. The discovery was somewhat accidental; they were applying high pressure to a mixture of ethylene gas and benzaldehyde, aiming to produce a different compound, when they noticed the formation of a waxy material, which was later identified as LDPE. This breakthrough led to the development of commercial processes to produce LDPE, which became widely used for its flexibility, toughness, and chemical resistance. LDPE revolutionized the packaging industry, among other applications, providing a versatile and inexpensive material for films, containers, and other products.