An Array of Colorful Polymers
Yellow, navy, maroon, midnight blue – what color shall it be? Milan-based researchers have found a way to synthesize different kinds of polyesters, their color being dependent on the starting substance only. “We are confident that these materials might find useful applications in the dye and paint industries,” Cristina Navarra and her co-authors write.
The researchers at Institute of Molecular Recognition in Milan, Italy
and at the University of Milan used an enzyme-catalyzed ring-opening
polymerization: they heated a colored amine or alcohol with an excess
of the colorless liquid ε-caprolactone overnight. With the help of the
enzyme Novozym 435, the ε-caprolactone ring was opened and several
molecules were linked together, with the initial amine or alcohol at
the beginning of the chain.
The researchers could modulate the polymer length by changing the
amine:caprolactone ratio. The chain length varied between 10 and 39
monomers. Almost all synthesized polyesters were colored powdery
solids, the researchers write; one product, however, was a viscous oil.