Low Density Polyethylene (LDPE) is produced through a free radical polymerization process, typically under high pressure (1000 to 3000 atm) and at high temperatures (80 to 300°C). The reaction occurs in a tubular reactor or an autoclave. Ethylene gas is the primary monomer used to produce LDPE. The process involves the initiation of a free radical, usually by peroxide, which triggers the polymerization of ethylene under the specified conditions. The high pressure aids in keeping the ethylene gas in a liquid state, facilitating the polymer chains' growth. This method produces a polymer with a highly branched structure, accounting for its lower density compared to High Density Polyethylene (HDPE), which is more linear. Adjusting the reaction conditions, such as temperature, pressure, and the concentration of initiators, can help control the product's properties, such as its density, melt flow index, and branching degree.

Polyvinyl chloride (PVC) is a widely used plastic found in a variety of products, from pipes to clothing. It does not inherently contain per- and polyfluoroalkyl substances (PFAS), which are a group of man-made chemicals used primarily for their water and oil resistance properties. However, it's important to note that additives used in the manufacturing process of PVC products could potentially include PFAS compounds to confer certain characteristics like durability or resistance to wear. This depends largely on the specific application and manufacturing choices. Therefore, while PVC itself does not contain PFAS, some PVC products could, theoretically, have PFAS as part of their formulation depending on their intended use and the decisions made by manufacturers.

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.