It is a hundred years ago this year that German chemist Hermann Staudinger introduced his macromolecular hypothesis, making him one of the founders of polymer chemistry.
Until then, scientists could not really imagine what polymers were at the molecular level. In his research into the synthesis of isoprene, the monomeric natural rubber compound, Staudinger discovered that polymers are long chains of short, repeating molecular units attached to each other via covalent bonds.
With this he explained the high molecular weights that were found in polymers. A discovery that earned him the Nobel Prize in Chemistry in 1953. Thanks to the macromolecular hypothesis, applicable plastics such as PVC could be developed.