Which characteristic describes thermosetting plastics?

Thermosetting plastics are characterized by their structure, which is formed through strong chemical bonds that create a rigid network. Once they are set or cured, these plastics cannot be remolded or reshaped upon reheating; they retain their form and strength. This permanence is primarily why thermosetting plastics are difficult to recycle. The intense and irreversible cross-linking of polymer chains that occurs during their curing process means that they can’t be melted down and reformed like thermoplastics can.

In contrast to thermoplastics, which can be reshaped and are more versatile in recycling processes, the rigid structure of thermosetting plastics leads to challenges in breaking them down for recycling. Therefore, the characterization of thermosetting plastics as hard to recycle is accurate, reflecting their inherent properties and the limitations imposed by their manufacturing process.