A team of scientists have produced paint primer on the basis of lignin – a plant residue and waste product from the production of bioethanol.
The research, from the Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM) in Bremen, could be a step towards reducing the dependence on fossil fuel resources, and adding a new value stream to bioethanol production.
Lignin is an abundant natural product. As a by-product of both paper and ethanol production, it is a source of growing interest to the biofuels industry. However, its challenging properties has hindered its widespread use.
The exact composition of a lignin mass depends on a number of factors, such as if it originated from paper or bioethanol production. This means producing a substance that always has similar reactions is complicated.
“Most previous approaches were based on producing lignin monomeric starting materials, which always have the same properties. Due to the different composition of the starting material this is quite complex,” explained Yvonne Wilke in a Fraunhofer IFAM press release.
“We took a different approach by standardising and modifying the whole substance. This gives us a raw material that we can say is always the same within certain limits.”
The Fraunhofer IFAM experts transformed the standardised mixture, and used it as a raw material for binders for primer formulations. The resultant primer has properties comparable to petrochemical equivalents in regards to corrosion protection, adhesion and applicability.
As lignin is produced from plant residues and waste products it has a low carbon footprint and good sustainability credentials, meaning the primer could be attractive to the automotive industry and others as they strive to reduce their environmental impact.
"Independence from fossil fuels is a tremendous goal. Especially considering the amount of products that are still based on fossil fuels," says Wilke. "With our project, we've been able to take a few steps in the right direction and to show that lignin is a real alternative in the manufacture of primers and adhesives, as well as that it brings us closer to independence from petrochemicals."