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
Union Sulphur Company land. He assumed that the sulfur deposits extended laterally underneath his property, and he planned to extract the sulfur with a new method. He would insert three pipes down into the sulfur. Super-heated water would be pumped down one pipe to melt the sulfur, and compressed air would be pumped down another pipe. The increased pressure from the compressed air would then force the molten sulfur up through the empty third pipe. Upon drilling on his property, however, Frasch discovered that the sulfur was only located beneath the American Sulphur Company property. The American Sulfur Company was not a fly-by-night