What happens if thermosets are heated too high?

When thermosetting polymers are subjected to high temperatures, they undergo thermal decomposition rather than becoming flexible or enhancing their strength. Unlike thermoplastics, which can be reheated and remolded, thermosets have a rigid structure formed through a chemical cross-linking process during curing. This cross-linked structure provides thermosets with excellent thermal and mechanical properties. However, if the temperature exceeds the material's thermal tolerance, the integrity of the cross-linking bonds is compromised, leading to decomposition.

During decomposition, the polymer chains break down, resulting in a loss of material properties and the potential release of volatile compounds. This thermal degradation is irreversible, and as such, once a thermoset has decomposed, it cannot revert to its original state or regain its mechanical properties. Understanding the behavior of thermosets under heat is crucial for engineers and technicians, as it informs proper handling, processing, and usage conditions to prevent undesirable outcomes.