All-cellulose composite laminates

A new processing method for fibre-reinforced all-cellulose composite (ACC) laminates has been developed in this work on the basis of a conventional hand lay-up method. Four layers of a man-made cellulosic textile (Cordenka rayon) and four layers of a natural fibre textile (linen), respectively, were impregnated with the ionic liquid (IL) 1-butyl-3-methylimidazolium acetate (BMIMAc). The impregnated layers were heated under pressure for the fibre surfaces to partially dissolve in the IL and to achieve compaction of the single laminae to form a composite. A matrix phase is formed in situ by the regeneration of dissolved fraction of the fibre via solvent exchange.Both textiles could be processed into thick (>1 mm) cellulose laminates. Analysis of the composite microstructure and phase transformations revealed that the dissolution behaviour of the man-made cellulose fibres was better than of the linen textile resulting in a more homogenous fibre–matrix-interphase and therefore better tensile properties.