Polymer architecture via abstraction of a hydrogen, can create a mid-chain growth site. Branching can be quantified by the branching index. An effect related to branching is chemical crosslinking - the formation of covalent bonds between chains. Crosslinking tends to increase T and increase strength and toughness. Among other applications, this process is used to strengthen rubbers in a process known as vulcanization, which is based on crosslinking by sulfur. Car tires, for example, are highly crosslinked in order to reduce the leaking of air out of the tire and to toughen their durability. Eraser rubber, on the other hand, is not
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