Polyketene

Polyketene is a polymer with the general formula (RCH=C=O)n, where R is typically hydrogen or an alkyl group. It is formed by the polymerization of ketenes, which are compounds of the general formula R2C=C=O. The polymerization process can be initiated by various catalysts, including anionic, cationic, or radical initiators, and often requires low temperatures. The resulting polymer chain consists of repeating carbon-carbon double bonds and carbonyl groups.

The properties of polyketene vary significantly depending on the specific ketene monomer used and the polymerization conditions. Polyketene itself, derived from ketene (R=H), is a highly reactive and unstable polymer that readily decomposes. Substituted polyketenes, where R is not hydrogen, tend to be more stable. For example, poly(methylketene) and poly(ethylketene) have been synthesized and studied. These polymers are generally insoluble in most common solvents and can exhibit crystalline structures.

Polyketenes are of interest in polymer chemistry due to their unique structure, which contains a conjugated system of double bonds and carbonyl groups. This structure can lead to interesting electronic and optical properties. However, their reactivity and the challenges in controlling their polymerization have limited their widespread commercial applications. Research continues to explore potential uses for polyketenes in areas such as specialty materials and as intermediates in organic synthesis.