Here, he successfully isolated a number of useful organic compounds (including a synthetic coffee flavoring) as more completely reviewed by Rolf Mülhaupt.

While at Karlsruhe and later, Zurich, Staudinger began research in the chemistry of rubber, for which very high molecular weights had been measured by the physical methods of Raoult and van 't Hoff.

Contrary to prevailing ideas (see below), Staudinger proposed in a landmark paper published in 1920 that rubber and other polymers such as starch, cellulose and proteins are long chains of short repeating molecular units linked by covalent bonds.

At the time, leading organic chemists such as Emil Fischer and Heinrich Wieland[5][11] believed that the measured high molecular weights were only apparent values caused by the aggregation of small molecules into colloids.

At first, the majority of Staudinger’s colleagues refused to accept the possibility that small molecules could link together covalently to form high-molecular weight compounds.

As Mülhaupt aptly notes, this is due in part to the fact that molecular structure and bonding theory were not fully understood in the early 20th century.

The X-ray diffraction studies of polymers by Herman Mark provided direct evidence for long chains of repeating molecular units.

[14][15][16] Staudinger's groundbreaking elucidation of the nature of the high-molecular weight compounds he termed Makromoleküle paved the way for the birth of the field of polymer chemistry.