New bio-composites based on short fibre reinforced hydroxypropylcellulose films

The present work deals with the preparation and the characterisation of solid films, having thickness between 15 and 40 mum, prepared with hydroxypropyl cellulose (HPC and different amounts of commercial cellulose fibres (0; 0.5: 10 and 15% w/w) (system A) and with 1,4-butyl diisocyanate (BDI), as a cross-linking agent (system B). Before the preparation of these films, the surface energy of cellulose fibres, as such and after purification with different solvents. was determined by Inverse Gas Chromatography (IGC), which gave the values of dispersive energy and acid-base properties of their surfaces. The tensile and photo-elastic properties of the solid films obtained were studied. There were no significant changes in Young's modulus between the two systems. However, as expected, the values of the elongation and those of the fracture stress were systematically higher for system B in comparison with system A. The same trend was found for the birefringence, measured at the same elongation values for the films obtained from both systems.