What are the effects of ozone exposure on the surface chemistry of WPC outdoor trash cans?

Ozone, a powerful oxidizing agent present in the lower atmosphere, significantly impacts the surface chemistry and long-term durability of Wood-Plastic Composite (WPC) outdoor trash cans. The primary effect is the oxidation of the polymer matrix, typically polyethylene or polypropylene. Ozone attacks the polymer chains, leading to chain scission. This breaks down the molecular structure, resulting in a reduction of the material's molecular weight and a loss of mechanical properties like strength and flexibility. Concurrently, the plastic component becomes more brittle.

The wood flour or fiber component within the WPC is also affected. Ozone can degrade the lignin in the wood, a complex polymer that provides rigidity. This degradation compromises the structural integrity of the wood particles and can weaken the bond between the wood and plastic phases. The combined chemical attack on both components accelerates the overall material degradation.

Visually, these chemical changes manifest as surface chalkiness, color fading, and micro-cracking. The surface becomes rough and more susceptible to water absorption and microbial growth, such as mold and mildew. Furthermore, ozone exposure can make the surface more vulnerable to further environmental damage from UV radiation and rain. Ultimately, prolonged ozone exposure shortens the functional lifespan of WPC trash cans by accelerating the erosion of the material's surface, leading to premature embrittlement, cracking, and failure. Understanding these effects is crucial for developing more resistant WPC formulations and for predicting the service life of outdoor products.