Radiators are typically not made from polypropylene or polyethylene due to these plastics' thermal characteristics. These materials do not have sufficient heat resistance and conductivity for the high temperatures involved in a radiator's operation. Radiators must efficiently transfer heat from the hot coolant inside to the air outside. Metals such as aluminum or steel are commonly used materials because they have much higher thermal conductivity and can withstand the operational conditions of radiators. Polypropylene and polyethylene are more likely to be found in components that do not require high heat resistance or conductivity, such as some automotive fluid containers or ducts.

Polypropylene (PP) is a thermoplastic polymer used extensively across various industries due to its versatile properties. It is known for its exceptional chemical resistance, elasticity, toughness, and fatigue resistance. This plastic is made from the polymerization of propylene monomers and can be categorized into different types based on tacticity, including atactic, isotactic, and syndiotactic, with isotactic being the most common due to its higher crystallinity and strength.

Polypropylene is widely used in packaging, textiles, automotive components, reusable containers, laboratory equipment, and medical devices owing to its ability to withstand high temperatures and being impervious to water. It is also favored for its lightweight nature and recyclability, which contribute to its preference in eco-friendly and sustainable product designs. Despite its many advantages, polypropylene's susceptibility to UV degradation and difficulty in adhesion without special treatments can be limitations in certain applications.

Medical polypropylene is a thermoplastic polymer widely utilized in the healthcare industry due to its excellent chemical resistance, sterilizability, and flexibility. Its primary uses include manufacturing surgical instruments, syringes, and medical containers. Due to polypropylene's ability to withstand high temperatures, it is suitable for autoclaving, ensuring sterilization of medical tools without degrading its properties. Furthermore, its flexibility and lightweight nature make it an ideal material for creating comfortable and durable prosthetic limbs and devices. The material is also used in packaging for medical devices, ensuring safety and maintaining the sterility of products during transport and storage. Another significant application is in suture manufacturing, where its non-absorbable nature is essential for wound closure procedures. The contribution of polypropylene to medical applications showcases its versatility and importance in developing safe, reliable, and practical medical products.