AkzoNobel Creates Paints Coatings From Nature
Organic chemists from the University of Groningen and AkzoNobel have developed a process that allows them to turn biomass into a high-quality coating using light, oxygen and UV light. This process combines a renewable source with green chemistry and could replace petrochemical-based monomers such as acrylates, which are currently used as building blocks for coatings, resins and paints. Lignocellulose makes up 20 to 30 per cent of the woody parts of plants and is the most abundantly available raw biomass material on Earth. Currently, it is mainly used as a solid fuel or used to produce biofuels. Lignocellulose can be cracked with acid to produce the chemical building block furfural, but this needs to be modified to make it suitable for the production of coatings. Researchers used a process that has been developed in their group to convert the furfural into a compound, hydroxybutenolide, that resembles acrylic acid. The chemical conversion uses only light, oxygen and a simple catalyst and produces no waste. The only side product is methyl formate, which is useful as a replacement for chlorofluorocarbons in other processes. Part of the structure of hydroxybutenolide is similar to acrylate, but the reactive part of the molecule is a ring structure. ‘This means that it is less reactive than acrylate and our challenge was to further modify the molecule so that it would produce a useful polymer.’ This was achieved by adding different green or biobased alcohols to the hydroxybutenolide, creating four different alkoxybutenolide monomers. These monomers can be transformed into polymers and coatings with the help of an initiator and UV light.