Rubber bands can shrink back after being stretched, which is the function of rubber molecules. Rubber molecules love to move, they are arranged hand in hand, because each molecule is always in active motion, so their team is always crooked and messy. If you pull the rubber band hard, the rubber molecules will lose the "freedom" to move arbitrarily, and the team they are arranged in will be neat and tidy, and the appearance will be stretched. However, these rubber molecules are not willing to be lonely, they want to restore their "freedom", so they will generate a force to restore the original state, which is the elasticity of rubber. This kind of rubber is actually a kind of raw rubber.
If it is stretched to a certain extent, the molecules will "slip" and can no longer return to their original state. In order to prevent the "slip" phenomenon between rubber molecules, the rubber molecules must be connected to each other to form a three-dimensional network. This method is called cross-linking, which is as elastic as a mesh door made of iron Barer . 1839 upptäckte Goodyear vulkaniserat gummi, som använder svavel som ett tvärbindningsmedel för att göra gummimolekylerna i de råa gummihållen på flera ställen och förvandlar det till ett högpresterande, elastiskt gummi .
Dagens gummiband är gjorda av detta elastiska gummi .
