INM Researchers to Develop Natural Resources-based Adhesives for Building Materials

The INM ? Leibniz Institute for New Materials is starting out on a joint pilot project with Namibia. Researchers from the Saarland and Africa will be developing adhesives obtained from natural resources and using them to produce sustainable building materials. The NaMiBIND project is scheduled to run for two years and the Federal Ministry of Education and Research (BMBF) is providing sponsorship to the tune of around 250,000 euros.

Namibia has acacias and sand in abundance. Acacia mellifera and Dichrostachys cinerea in particular change the biodiversity of plants and animals by bush encroachment and in doing so pose a threat to entire ecosystems. In order to halt their growth, the shrubs have up to now simply been cut down and used as fuel.

The INM, in partnership with the UNAM University and Polytechnic of Namibia along with the Namibian Business & Innovation Centre (NBIC) is keen to find a way to use the proliferous bushes in the form of ecologically certified basic wood materials as sustainable building materials. Their aim in this is to use sand from Namibia’s desert and the natural ingredients in acacias as components of an adhesive that they can combine with the acacia wood to produce simple construction panels similar to chipboard. The sale of these materials in Africa and exports will at the same time provide a boost for economic prosperity in Africa, and means that sand and scrub will remain in a cycle that is both sustainable and environmentally friendly, beneficial to the economy and socially acceptable, according to Rainer Hanselmann, Head of Sales at the INM.

"Typical binders used today for wood chipboards are composed of industrial polymers and resins, some of which are highly flammable", explains Ingrid Weiss, Head of the Biomineralization Program Division. In her opinion, "the development of alternative binders made from inorganic precursors based on INM technology will pave the way for manufacturing materials that are highly heat-resistant, water-repellent and antimicrobicidal. But for economic purposes this technology is far too expensive".

"As the basis of our new "Namib" binder, we will be using sand directly from the desert and first of all turn it into glass using simple, proven processes with potassium carbonate", says the biologist. "This glass is then powdered and converted to a "water glass suspension". Other components, such as certain hydrocarbons, would be provided by the acacias themselves. And this is the point where the new development in the sustainable process kicks in.

There are a number of varieties of acacia bushes in Namibia, including Acacia mellifera, Acacia reficiens, Dichrostachys cinerea, Colophospermum mopane, Terminalia sericea and Rhigozum trichotomum. "In order to be able to use these as building materials and binders, we need to