The oxidation of polypropylene (PP) primarily involves a radical mechanism, initiated by the abstraction of hydrogen atoms, creating macroradicals. This process generally begins with the formation of hydroperoxides upon exposure to oxygen and light. These hydroperoxides further decompose into various radicals that propagate the oxidation process, leading to the formation of ketones, alcohols, and carboxylic acids. The oxidation rate is influenced by factors such as temperature, presence of catalysts, and the PP's crystallinity. Antioxidants are often added to PP to slow down oxidation by scavenging radicals or decomposing hydroperoxides, thereby enhancing its stability and lifespan. Understanding and controlling the oxidation mechanism is crucial in improving the durability and performance of polypropylene in various applications.

Polypropylene, a versatile and widely used plastic, comes in a broad spectrum of colors. Due to its polymer structure, it can be manufactured in virtually any color by adding different pigments or dyes during the production process. Manufacturers often produce polypropylene in standard colors like black, white, various shades of blue, red, green, yellow, and many more. For specific applications, custom colors can also be created to meet the exact needs of customers. This flexibility in coloring makes polypropylene ideal for a wide range of products, including packaging, automotive parts, textiles, and consumer goods. It's important for manufacturers and product designers to consider the end use of the product, as the color of polypropylene can affect the product's aesthetic appeal, visibility, and even functionality in certain applications.

Polyvinyl Chloride Pipe, or PVC pipe, is a type of plastic piping widely used in various plumbing and water handling applications. Made from a combination of chlorine and ethylene, PVC pipes are known for their durability, resistance to corrosion, and relatively low cost. They are lightweight, easy to install, and require minimal maintenance, making them a popular choice for residential, commercial, and industrial plumbing systems. PVC pipes can handle a wide range of temperatures but are not suitable for hot water lines without modification. They are available in various sizes and strengths, classified by their thickness and pressure ratings, to suit different requirements. Due to their versatility and cost-effectiveness, PVC pipes play a crucial role in modern infrastructure, though environmental concerns have been raised regarding their production and disposal.