Vulcanizing rubber joins all the rubber molecules into one single humongous molecule. In other words, the sole of a sneaker is made up of a single molecule.

One Big Happy Molecule

Science Sidetrip:

Then there comes onto the scene a tinkerer named Charles Goodyear. In the winter of 1839 Goodyear was in Massachusetts trying to figure out how to make natural rubber more useful so that he could finally make a living at his until-now fruitless tinkering. He had mixed rubber latex and sulfur together when he had a little accident. He spilled the mixture on a hot stovetop. When the mixture was through frying, Goodyear couldn’t believe what had happened.

Wouldn’t you know sulfur was just the extra ingredient he needed to make rubber work in cold weather. After mixing hot gooey rubber latex and sulfur and letting the mixture cool, he took the rubbery solid that resulted and tacke… Continue Reading

Source: https://pslc.ws/macrog/exp/rubber/sepisode/spill.htm