What are the effects of prolonged UV exposure on the molecular weight of polyethylene?
Prolonged exposure to ultraviolet (UV) radiation significantly impacts the molecular weight of polyethylene, a widely used polymer. UV radiation initiates photodegradation, breaking the polymer chains through oxidative reactions. This process leads to chain scission, reducing the average molecular weight of the material. As a result, polyethylene becomes more brittle and loses its mechanical strength, compromising its durability. The degradation is accelerated in the presence of oxygen, forming carbonyl groups that further weaken the polymer structure. Understanding these effects is crucial for improving polyethylene's UV resistance in outdoor applications.
