Biobased Products from Plant Resources

Plants supply useful applications in chemistry, either directly, or following the biotechnological and/or chemical transformation (hemisynthesis) of materials from agriculture or forestry. Traditional processes for making colours, fibres and materials drew on know-how, the underlying scientific basis of which remained unknown until chemistry emerged as a scientific discipline.

The strategy used to identify plant-use pairings starts with the target useful property, going back through the whole range of crop management operations to select the plant producing the desired structures. Two main approaches are utilised to identify the desired structures (fibres) and biomolecules in plants. The first, the functional approach, is an innovative one. It consists in exploring the molecules which exist in the plant sphere and their derivatives to find functions similar to those being sought, even if such functions are carried by molecules in different structures from those currently used. This approach may require functionalisation, the modification of macromolecule assemblies or the introduction of chemical groupings (in molecules or macromolecules) to confer on them the desired properties for use. The second, the structural approach, consists in identifying biomolecules which are identical or similar to those used in carbon fossil chemistry, and adapting the biomass transformation process to bring about substitution.

The two approaches may coexist for the same property. Thus rubber material can be produced either from the polymer which makes up latex in the rubber tree, or chemically polymerised from butadiene which is obtained by the fermentation of oses.

The purpose of this article is to move beyond simple curiosity about the chemical uses of plants, to define key rules enabling us to select a plant and its cropping system with a view to establishing a biobased resource to satisfy a useful function. Alternative resources such as algae, microalgae, and cyanobacteria are possible, often in niche markets. The reader may also like to refer to other specialist articles in the Techniques de l’Ingénieur  [IN 201][CHV 4 030]