Methods for the production of a biodegradable plastics material obtained from plant waste materials are provided which include the steps of dissolving plant waste material in an anhydrous solvent which includes anhydrous trifluoroacetic acid in order to dissolve a cellulose fraction of the material, the waste material being at least partly dehydrated in such a way that its water content is not likely to cause hydrolysis of the cellulose fraction, and removing the solvent from the solution containing the non-hydrolyzed cellulose fraction.