How does the color of polypropylene change over time outdoors?

Polypropylene, a widely used plastic, undergoes noticeable color changes when exposed to outdoor conditions over time. The primary factor driving this transformation is ultraviolet (UV) radiation from sunlight. UV rays break down the polymer chains in polypropylene, leading to a process called photodegradation. This degradation causes the material to lose its original color, often turning yellow or brown.

Additionally, environmental factors such as temperature fluctuations, humidity, and exposure to pollutants can accelerate this process. Over time, the surface of polypropylene may also become brittle and develop cracks, further altering its appearance. Stabilizers and additives are sometimes incorporated into polypropylene to slow down these changes, but prolonged outdoor exposure will inevitably lead to discoloration and material degradation. Understanding these changes is crucial for industries relying on polypropylene for outdoor applications, as it impacts both aesthetics and functionality.