Rubber toughening and damage competition theory. In material selection it is important to look at the interaction between the matrix and the secondary phase. For example, crosslinking within the rubber phase will promote high strength fibril formation that will toughen the rubber, preventing particle fracture. Carboxyl-terminated butadiene-acrylotnitrile (CTBN) is often used to toughen epoxies, but using CTBN alone increases the toughness at the cost of stiffness and heat resistance. Amine-terminated butadiene acrylonitrile (ATBN) is also used. Using ultra-fine full-vulcanized powdered rubber (UFPR) researchers have been able to improve all three, toughness, stiffness, and heat resistance simultaneously, resetting the stage for rubber toughening
Thiokol Thiokol Thiokol (variously Thiokol Chemical Corporation, Morton-Thiokol Inc., Cordant Technologies Inc., Thiokol Propulsion, AIC Group, ATK Thiokol, ATK Launch Systems Group; finally Orbital ATK before becoming part of Northrop Grumman) was an American corporation concerned initially with rubber and related chemicals, and later with rocket and missile propulsion systems. Its name is a portmanteau of the Greek words for sulfur (θειον ""theion"") and glue (κολλα ""kolla""), an allusion to the company's initial product, Thiokol polymer. The Thiokol Chemical Company was founded in 1929. Its initial business was a range of synthetic rubber and polymer sealants. Thiokol was a major supplier