What are the differences in thermal expansion between PVC and polypropylene outdoor flower boxes?

When selecting outdoor flower boxes, understanding the thermal expansion properties of materials like PVC and polypropylene is crucial for long-term durability. PVC (Polyvinyl Chloride) has a higher coefficient of thermal expansion compared to polypropylene, meaning it expands and contracts more significantly with temperature fluctuations. This can lead to warping or cracking over time, especially in extreme climates. Polypropylene, on the other hand, exhibits lower thermal expansion, making it more stable and resistant to deformation in varying temperatures.

Additionally, PVC tends to become brittle in cold weather, while polypropylene retains its flexibility, reducing the risk of damage. For outdoor use, polypropylene flower boxes are often the better choice due to their superior resistance to thermal stress. However, PVC remains popular for its affordability and ease of molding. Consider your local climate and budget when deciding between these materials for your outdoor planters.