Abstract
It has long been known that acetaldehyde is polymerized to give amorphous polyacetaldehyde when the monomer is frozen. In this method freezing of the monomer was an indispensable process.
Recently we found that alumina was a more effective catalyst for amorphous polymerization. Acetaldehyde was easily converted to high polymer without freezing of the monomer.
Furthermore, Natta et al. and ourselves succeeded respectively in the preparation of the crystalline polymer of aldehydes by organometallic compounds and metal alkoxide. The crystalline polymer is much less soluble in organic solvents than the amorphous one.
The mechanism of the stereoregular polymerization was considered in connection with several synthetic organic reactions which involve metal alkoxides and carbonyl compounds. The coordination complex of aldehyde to the metal alkoxide seems to play an influential role in the stereoregular polymerization.
