Giulio Natta and the Origins of Stereoregular Polymers

Abstract

The name of Natta is entwined inextricably with that of Ziegler,in the famous catalyst systems known by their names andused to make polyethylene and polypropylene. Unlike ethylene,which is achiral, propylene is a prochiral molecule andupon polymerization can lead to interesting stereochemicaland regiochemical enchainment sequences. Natta’s presciencein recognizing this unique feature of propylene led to the discoveryof crystalline isotactic polypropylene and the beginningof a new industry. The story of how Natta discoveredpolypropylene is an engrossing one – one of stiff competitionamongst contemporaries, Natta’s intimate relationship withthe Italian industries, and his unique scientific background.Natta’s identification of isotactic polypropylene as a righthandedthree fold ‘single helix’ in March 1954, in quick successionto the discovery of DNA ‘double helix’ by Watson,Crick, and Rosalind Franklin (March 1953), and the coiledcoilmotif of ‘triple helix’ of collagen by G N Ramachandran(August 1954), makes this period the ‘golden age of macromolecularcrystallography’.