What are synthetic or natural organic polymers known for being shaped when soft and then hardened?

The term that describes synthetic or natural organic polymers that can be shaped when soft and then hardened is plastics. Plastics are versatile materials that undergo a process known as polymerization, where long chains of monomer units form a solid material. This characteristic allows plastics to be molded into various shapes and forms when they are heated and softened. Upon cooling, they retain the shape they were formed into.

Plastics are used in a vast array of products and applications due to their durability, resistance to corrosion, and lightweight nature. This unique property of being malleable when heated and becoming rigid upon cooling makes plastics a preferred choice in manufacturing processes across numerous industries.

While resins can also be shaped and hardened, they are typically used as a precursor or component in the production of plastics. Wax materials are generally used for different applications like coatings or for crafting, and they do not have the same widespread functionality as plastics. Fiberglass involves glass fibers that are combined with resins but does not fit the basic definition of a polymer shaped when soft; the fiberglass itself is not the polymer but rather a composite material. Therefore, plastics distinctly embody the characteristic of being organic polymers that can be softened and then hardened into various forms.