Stronger polymers
Toray Industries, Inc. (Tokyo, Japan; www.toray.com) has created a new polymer that retains the outstanding thermal resistance, rigidity and strength of polyamide 6 (PA6), while having a bending-fatigue limit that is 15 times that of conventional polymers. Prospective applications for such durability include automobiles, appliances and sporting goods.
Toray focused on polyrotaxane — a supramolecular polymer with a beaded or necklace-like structure, its molecules consisting of strings and rings — which has a sliding molecular bond, as a polymer whose structure moves in response to external forces. The company endeavored to balance the inherent attributes of PA6 and fatigue resistance by finely dispersing polyrotaxane in the resin.
Toray used its proprietary Nanoalloy microstructure-control technology to maximize the effectiveness of polyrotaxane by dispersing it in the 10-nm crystals of PA6. The resulting flexible stress-dispersion mechanism led to the creation of the new polymer.