Answer:
They cannot be re-melted by heating to form into new shapes.
Explanation:
Recycling refers to the process of melting a plastic and making it into another shape or size.
Thermoplastics can be softened repeatedly, melted and remoulded. Thermosetting polymers can not be softened, melted and remoulded once they are formed.
Hence, thermosetting polymers cannot be re-melted by heating to form into new shapes therefore they can't be recycled.