How does the glass transition temperature of PVC affect its cold-weather performance?

The glass transition temperature (Tg) of PVC plays a critical role in determining its performance in cold weather. PVC, a widely used thermoplastic polymer, becomes rigid and brittle below its Tg, which typically ranges between 70°C to 85°C for unplasticized PVC. In cold environments, as temperatures approach or drop below the Tg, the polymer chains lose mobility, reducing flexibility and increasing the risk of cracking or fracture.

Plasticizers can lower the Tg of PVC, improving its cold-weather durability by maintaining flexibility at lower temperatures. However, unmodified PVC may exhibit poor impact resistance in freezing conditions, limiting its applications in outdoor or low-temperature settings. Understanding the relationship between Tg and environmental conditions helps engineers select appropriate PVC formulations for optimal performance in cold climates.