How does the melting point of PVC limit its use in high-temperature environments?

PVC (Polyvinyl Chloride) is a widely used thermoplastic polymer known for its versatility and cost-effectiveness. However, its relatively low melting point of around 160-210°C (320-410°F) significantly limits its application in high-temperature environments. When exposed to temperatures approaching its melting range, PVC begins to soften, lose structural integrity, and may eventually deform or melt. This thermal instability makes PVC unsuitable for applications requiring prolonged exposure to heat, such as automotive engine components, industrial piping for hot fluids, or construction materials in high-temperature zones. Additionally, PVC can release hazardous hydrochloric acid gas when overheated, creating safety concerns. For these reasons, alternative materials with higher thermal resistance, such as CPVC, PTFE, or ceramic composites, are often preferred for high-temperature applications. Understanding PVC's thermal limitations helps engineers and designers select appropriate materials for specific temperature conditions.