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
Polymer Corporation Polymer Corporation Polymer Corporation was a Canadian federal crown corporation established in 1942 to produce artificial rubber to substitute for overseas supply cut off by World War II. After the Japanese captured the Dutch East Indies in 1942, most of the world's supply of natural rubber was out of Allied hands. Due to the importance of rubber products for both modern life and modern warfare, the loss of such an important resource at this phase in the war was a crisis. A factory was established in Sarnia, Ontario, using German patents from an American licensee. Polymer produced approximately 3,300 tons