What is the characteristic of a thermosetting plastic?

A thermosetting plastic is characterized by its inability to be remelted and reshaped after it has been formed and cured. This unique property arises from the chemical cross-linking that occurs during the curing process, which permanently sets the material into a rigid structure. Once cured, the molecular structure of thermosetting plastics is stable and cannot be altered by heat. This inherent stability makes them ideal for applications requiring durable and heat-resistant materials, such as in electrical insulation, automotive parts, and kitchenware. The other options do not accurately describe thermosetting plastics; they might suggest properties associated with thermoplastics or mischaracterize the behavior of such materials.