French team invents tough, reheatable plastic

French researchers have designed a polymer that can be heated and reshaped, and yet remains as strong as well-known industrial plastics, according to a study Thursday in the US journal Science. The material is unusual because it "can be repeatedly processed at high temperatures... it can even be ground up and recycled into a new shape while retaining the mechanical properties of the original material," said the study. Complex shapes "can be easily made without resort to a mold" and since the material will not melt, precision heat tools are not necessary and a hot air blower is sufficient, it added. Once further developed, the material could find uses in aircraft and automobile parts, construction, electronics and sports equipment. Until now, synthetic polymers have been divided into two classes -- thermoplastics that can be melted and remolded, and thermosets that are processed into liquid, chemically infused and molded into a permanent shape. The latter are the strongest and most stable, particularly at high temperatures, and are often used in aircraft. But they cannot be broken down again and reshaped. The material created by Damien Montarnal and colleagues at the Ecole Superieure de Physique et Chimie Industrielles in Paris, is as strong as a thermoset but can be repeatedly manipulated into different forms. "It can even be ground up and recycled into a new shape while retaining the mechanical properties of the original material," said the study. The material has not yet reached mass production, but researchers said the process for making it could be "readily scaled up for applications and generalized to other chemistries."